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Chen XF, Zhang YC, Ding N, Liu L, Ji YD, Zhang C, Chi J. Radiation dose reduction and image quality in pediatric paranasal sinus CT: with automatic tube current modulation and iterative reconstruction technique. RADIATION PROTECTION DOSIMETRY 2024; 200:1470-1476. [PMID: 39270666 DOI: 10.1093/rpd/ncae192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/31/2024] [Accepted: 08/26/2024] [Indexed: 09/15/2024]
Abstract
Our objective is to evaluate radiation dose and image quality in pediatric paranasal sinus computed tomography (CT) with automatic tube current modulation (ATCM) and sinogram-affirmed iterative reconstruction algorithm (SAFIRE). CT scans from 80 patients were divided into two groups: Group A [80 kVp, pitch 1.5, 40 mAs, the filtered back projection (FBP) algorithm] and Group B (70 kVp, pitch 3, ATCM with reference at 40 mAs, SAFIRE strengths 1-5). We have evaluated image quality and radiation dose. Group B demonstrated significantly lower volume computed tomography dose index, dose-length product, and effective dose than Group A (0.13 ± 0.03 vs. 1.57 ± 0.01 mGy, 2.27 ± 0.82 vs. 19.88 ± 2.01 mGy·cm, and 0.0081 ± 0.0017 vs. 0.079 ± 0.013 mSv, respectively; P < .001). Increasing SAFIRE strengths correlated with noise reduction and SNR enhancement. Group B's noise and SNRsoft at SAFIRE strength 5 were comparable with Group A. Images reconstructed with SAFIRE strength 5 in Group B exhibit comparable image quality with FBP in Group A.
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Affiliation(s)
- Xiao-Fang Chen
- Department of Radiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
| | - Yi-Chi Zhang
- Department of Radiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
| | - Ning Ding
- Department of Radiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
| | - Li Liu
- Department of Radiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
| | - Yi-Ding Ji
- Department of Radiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
| | - Chao Zhang
- Department of Anesthesiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
| | - Jing Chi
- Department of Radiology, Suzhou Ninth People's Hospital Affiliated to Soochow University, No. 2666 Ludang Rd, Wujiang District, Suzhou, Jiangsu 215200, China
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Sedira N, Pinto J, Ginja M, Gomes AP, Nepomuceno MCS, Pereira S. Investigating the Architecture and Characteristics of Asian Hornet Nests: A Biomimetics Examination of Structure and Materials. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7027. [PMID: 37959626 PMCID: PMC10647307 DOI: 10.3390/ma16217027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/28/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023]
Abstract
This study investigates the internal architecture of Asian hornet nests (AHNs) using advanced imaging techniques, such as CT scanning and X-ray radiography, to understand their construction and function. The primary objective and significance of this study centre on drawing inspiration from the creative way Asian hornets construct their nests, with a particular focus on the architecture, design, functionality, and building materials of these nests. The architectural principles governing the construction of these nests, such as the arrangement of hexagonal cells, pedicels for load bearing, and adhesive materials, serve as a source of inspiration for innovative and sustainable design practices. The pedicels in Asian hornet nests play a crucial role in transferring load and ensuring stability. Additionally, AHNs' adhesion to tree branches is essential for preventing collapse, and the pedicels provide necessary structural support. The knowledge gained from studying AHNs' internal architecture could be applied directly to the architecture and civil engineering fields to improve structure stability and durability. The microstructure analysis of the paper-like material that hornets produce to build their nests indicates a complex and heterogeneous structure, composed of various plant fragments and fibres. This unique composition creates intricate grooves and pores, which are essential for regulating temperature and humidity levels within the outer envelope of the nest. The study of Asian hornet nests' internal structure demonstrated that nature's engineering principles inspire the design of durable and resilient structures in the construction industry. Civil engineers can incorporate similar principles into their designs to enhance the structural integrity and performance of buildings, bridges, and other infrastructure.
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Affiliation(s)
- Naim Sedira
- University of Trás-os-Montes e Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (J.P.); (M.G.); (S.P.)
- C-MADE–Centre of Materials and Building Technologies, UBI, 6201-001 Covilhã, Portugal
| | - Jorge Pinto
- University of Trás-os-Montes e Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (J.P.); (M.G.); (S.P.)
- C-MADE–Centre of Materials and Building Technologies, UBI, 6201-001 Covilhã, Portugal
| | - Mário Ginja
- University of Trás-os-Montes e Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (J.P.); (M.G.); (S.P.)
- Centre for Animal Sciences and Veterinary Studies (CECAV), UTAD, 5000-801 Vila Real, Portugal
| | - Ana P. Gomes
- University of Beira Interior (UBI), 6201-001 Covilhã, Portugal; (A.P.G.); (M.C.S.N.)
- FibEnTech–Fiber Materials and Environmental Technologies, Optical Centre, UBI, 6201-001 Covilhã, Portugal
| | - Miguel C. S. Nepomuceno
- C-MADE–Centre of Materials and Building Technologies, UBI, 6201-001 Covilhã, Portugal
- University of Beira Interior (UBI), 6201-001 Covilhã, Portugal; (A.P.G.); (M.C.S.N.)
- Lab2PT, Landscape, Heritage and Territory Laboratory, 4800-058 Guimarães, Portugal
| | - Sandra Pereira
- University of Trás-os-Montes e Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (J.P.); (M.G.); (S.P.)
- C-MADE–Centre of Materials and Building Technologies, UBI, 6201-001 Covilhã, Portugal
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Westmark S, Hessellund T, Hoffmann A, Madsen BB, Jensen TS, Gielen M, Bøggild H, Leutscher PDC. Increasing use of computed tomography scans in the North Denmark Region raises patient safety concern. Eur J Radiol 2023; 166:110997. [PMID: 37499480 DOI: 10.1016/j.ejrad.2023.110997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/04/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
PURPOSE Use of computed tomography (CT) scans raises safety concern as lifetime cumulative ionising radiation exposure is associated with risk of developing malignancies. This study aimed to investigate use of abdominal CT scans in the Danish health care sector. METHODS Data on abdominal CT scans performed annually in the North Denmark Region between 2005 and 2018 were extracted from the regional registry with emphasis on patients with a medical history of a repeated abdominal CT scan within 28 days. An audit of the medical files was subsequently conducted in 100 randomly selected patient cases to evaluate clinical information being provided, in addition to justification for a repeated abdominal CT scan, and finally if other radiology modalities could have been applied. RESULTS Number of annually performed abdominal CT scans in this demographically stable regional population increased by a factor 4.3 from 15 in 2005 to 65 in 2018 per 1,000 inhabitants. The audit revealed that 31% of the secondabdominal CT scans within a 28 days period were categorized as either doubtful whether justified or not justified. Moreover, 20% of theCT scans were considered replaceable by ultrasonography. CONCLUSIONS Annual performance of abdominal CT scans increased fourfold during the 14 years period. This tendency is probably attributable to changes in the Danish health care sector by which CT scan examination are used more frequently aiming at more accelerated patient investigation flow in conjunction with shorter length of hospitalization stay. Alertness is strongly warranted towards the associated risk of cancer due to life-time cumulative ionising radiation exposure by this strategy.
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Affiliation(s)
- Signe Westmark
- Centre for Clinical Research, North Denmark Regional Hospital, Hjoerring, Denmark
| | - Thomas Hessellund
- Department of Radiology, Clinic for Diagnostics, North Denmark Regional Hospital, Hjoerring, Denmark
| | - Andreas Hoffmann
- Department of Radiology, Gødstrup Regional Hospital, Gødstrup, Denmark
| | | | - Trine S Jensen
- Centre for Clinical Research, North Denmark Regional Hospital, Hjoerring, Denmark
| | - Mahican Gielen
- Department of Radiology, Clinic for Diagnostics, North Denmark Regional Hospital, Hjoerring, Denmark
| | - Henrik Bøggild
- Public Health and Epidemiology Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; Unit of Clinical Biostatistics, Aalborg University Hospital, Aalborg, Denmark
| | - Peter Derek Christian Leutscher
- Centre for Clinical Research, North Denmark Regional Hospital, Hjoerring, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
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Turkistani MH, Amer RR. Utilizing Triage Data for Medical Imaging Studies in the Emergency Department. Cureus 2023; 15:e41234. [PMID: 37529516 PMCID: PMC10387579 DOI: 10.7759/cureus.41234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2023] [Indexed: 08/03/2023] Open
Abstract
The use of radiological images is widespread in the emergency department (ED) as physicians commonly rely on them during initial evaluations to confirm diagnoses, contributing to prolonged waiting times. This study aimed to determine the relationship between commonly gathered triage data and the need for radiological imaging. Data were collected from electronic charts that contained routinely collected hospital data at the time of triage in the King Abdulaziz Medical City (KAMC) in Riyadh ED. The binary logistic regression results demonstrated a statistically significant relationship between age and radiological imaging ordered in the ED. Each one-unit increase in age corresponded to a 0.983-fold increase in the likelihood of ordering radiological imaging (odds ratio: 0.983, 95% confidence interval: 0.972-0.995, p = 0.004). In contrast, hypertension, diabetes, and heart failure were independent predictors of the need for radiological imaging in the ED (p >0.05). Patient data that are immediately available during ED triage can be used to predict the need for radiological imaging during ED visits. Such models can identify patients who may require radiological imaging during ED visits and expedite patient disposition.
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Affiliation(s)
| | - Roaa R Amer
- Emergency Department, King Abdulaziz Medical City, Riyadh, SAU
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A new approach to dose reference levels in pediatric CT: Age and size-specific dose estimation. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2022.110698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Masuda T, Funama Y, Nakaura T, Sato T, Urayama K, Kiguchi M, Oku T, Yoshida M, Arao S, Ono A, Hiratsuka J, Awai K. Usefulness of large beam-shaping filters at different tube voltages of newborn chest CT. Phys Eng Sci Med 2023; 46:289-293. [PMID: 36633769 DOI: 10.1007/s13246-023-01217-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/10/2022] [Accepted: 01/03/2023] [Indexed: 01/13/2023]
Abstract
BACKGROUND To investigate optimizing the use of different beam shaping filters (viz. small, medium and large) when using different tube voltages during the newborn chest computed tomography (CT) on a GE Lightspeed VCT scanner. METHODS We used pediatric anthropomorphic phantoms with a 64 detector-row CT scanner while scanning the chest. A real-time skin dosimeter (RD - 1000; Trek Corporation, Kanagawa, Japan) was positioned into the phantom center of the body, the surface of the body back, and the right and left mammary glands. We performed and compared six scan protocols using small, medium, and large beam shaping filters at 80 and 120 kVp protocols. RESULT There were no significant differences in the image noise for the chest scan among the different beam shaping filters. By using the large beam shaping filter at 80 kVp, it was possible to reduce the exposure dose by 5% in comparison with the small beam shaping filter, and by 10% in comparison with the medium beam shaping filter. By using the large beam shaping filter at 120 kVp, it was possible to reduce the exposure dose by 15% in comparison with the small beam shaping filter and by 20% in comparison with the medium beam shaping filter (p < 0.01). CONCLUSION The large beam shaping filter had the most dose reduction effect during newborn chest CT on a GE Lightspeed VCT scanner. The additional copper filtration being present in the large bowtie filter of the GE Lightspeed CT scanner when using different tube voltages is more effective in reducing radiation exposure in children.
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Affiliation(s)
- Takanori Masuda
- Department of Radiological Technology, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, 701-0193, Kurashiki-city, Okayama, Japan.
| | - Yoshinori Funama
- Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, 860-8556, Kumamoto, Japan
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, 860-8556, Kumamoto, Japan
| | - Tomoyasu Sato
- Department of Diagnostic Radiology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, 730-8655, Hiroshima, Japan
| | - Kotaro Urayama
- Department of Pediatric cardiology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, 730-8655, Hiroshima, Japan
| | - Masao Kiguchi
- Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3 Minami-ku, 734-8551, Hiroshima, Japan
| | - Takayuki Oku
- Department of Radiological technologist, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, 730-8655, Hiroshima, Japan
| | - Masato Yoshida
- Department of Radiological technologist, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, 730-8655, Hiroshima, Japan
| | - Shinichi Arao
- Department of Radiological Technology, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, 701-0193, Kurashiki-city, Okayama, Japan
| | - Atsushi Ono
- Department of Radiological Technology, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, 701-0193, Kurashiki-city, Okayama, Japan
| | - Junichi Hiratsuka
- Department of Radiological Technology, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, 701-0193, Kurashiki-city, Okayama, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3 Minami-ku, 734-8551, Hiroshima, Japan
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Shubayr N, Alashban Y. Estimation of radiation doses and lifetime attributable risk of radiation-induced cancer in the uterus and prostate from abdomen pelvis CT examinations. Front Public Health 2023; 10:1094328. [PMID: 36699908 PMCID: PMC9868812 DOI: 10.3389/fpubh.2022.1094328] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/21/2022] [Indexed: 01/12/2023] Open
Abstract
Computed tomography (CT) scans are one of the most common radiation imaging modalities, and CT scans are rising steadily worldwide. CT has the potential to enhance radiography practice, but it also has the risk of drastically increasing patient doses. One CT procedure for the abdomen pelvis (AP) area can expose a patient's prostate or uterus to a substantial radiation dose, leading to concerns about radiation-induced cancer. This study aimed to estimate organ doses of the uterus and prostate and evaluate the lifetime attributable risk (LAR) of cancer incidence and mortality resulting from AP CT examinations. This retrospective study included 665 patients, of which 380 (57%) were female, and 285 (43%) were male. Data were collected from the picture archiving and communication system for AP CT procedures and exposure parameter data. Organ doses for the uterus and prostate were calculated using National Cancer Institute CT (NCICT) software. Based on the risk models proposed by the BEIR VII report, the calculated organ doses were used to estimate the LAR of prostate and uterus cancer incidence and mortality due to radiation exposure from AP CT procedures. The mean effective dose resulting from AP CT for females and males was 5.76 ± 3.22 (range: 1.13-12.71 mSv) and 4.37 ± 1.66 mSv (range: 1.36-8.07 mSv), respectively. The mean organ dose to the uterus was 10.86 ± 6.09 mGy (range: 2.13-24.06 mGy). The mean organ dose to the prostate was 7.00 ± 2.66 mGy (range: 2.18-12.94 mGy). The LAR of uterus and prostate cancer incidence was 1.75 ± 1.19 cases and 2.24 ± 1.06 cases per 100,000 persons, respectively. The LAR of cancer mortality rates from uterus and prostate cancers were 0.36 ± 0.22 and 0.48 ± 0.18 cases per 100,000 persons, respectively. The LAR of prostate and uterus cancer occurrence and mortality from radiation doses with AP CT procedures was low but not trivial. Therefore, efforts should be made to lower patient doses while retaining image quality. Although the minimization of the patient's radiation dose must guide clinical practice, the estimated slight increase in risk could aid in easing fears regarding well-justified AP CT procedures.
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Affiliation(s)
- Nasser Shubayr
- Department of Diagnostic Radiography Technology, College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia,*Correspondence: Nasser Shubayr ✉
| | - Yazeed Alashban
- Radiological Sciences Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
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Tamam N, Salah H, Rabbaa M, Abuljoud M, Sulieman A, Alkhorayef M, Bradley D. Evaluation of patients radiation dose during mammography imaging procedure. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Hu X, Gou J, Lin W, Zou C, Li W. Size-specific dose estimates of adult, chest computed tomography examinations: Comparison of Chinese and updated 2017 American College of Radiology diagnostic reference levels based on the water-equivalent diameter. PLoS One 2021; 16:e0257294. [PMID: 34516579 PMCID: PMC8437305 DOI: 10.1371/journal.pone.0257294] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 08/28/2021] [Indexed: 11/29/2022] Open
Abstract
Rationale and objectives This study aimed to compare the volume computed tomography dose index (CTDIvol), dose length product (DLP), and size-specific dose estimate (SSDE), with the China and updated 2017 American College of Radiology (ACR) diagnostic reference levels (DRLs) in chest CT examinations of adults based on the water-equivalent diameter (Dw). Materials and methods All chest CT examinations conducted without contrast administration from January 2020 to July 2020 were retrospectively included in this study. The Dw and SSDE of all examinations were calculated automatically by “teamplay”. The CTDIvol and DLP were displayed on the DICOM-structured dose report in the console based on a 32cm phantom.The differences in patient CTDIvol, DLP, and SSDE values between groups were examined by the one-way ANOVA. The differences in patient CTDIvol, DLP, and SSDE values between the updated 2017 ACR and the China DRLs were examined with one sample t-tests. Results In total 14666 chest examinations were conducted in our study. Patients were divided into four groups based on Dw:270 (1.84%) in 15–20 cm group, 10287 (70.14%) in the 21–25 cm group, 4097 (27.94%) in the 26–30 cm group, and 12 (0.08%) patients had sizes larger than 30 cm. CTDIvol, DLP, and SSDE increased as a function of Dw (p<0.05). CTDIvol was smaller than SSDE among groups (p<0.05). The mean CTDIvol and DLP values were lower than the 25th, 50th, and 75th percentile of the China DRLs (p <0.05). The CTDIvol, DLP, and SSDE were lower than the 50th and 75th percentiles of the updated 2017 ACR DRLs (p <0.05) among groups. Conclusions SSDE takes into account the influence of the scanning parameters, patient size, and X-ray attenuation on the radiation dose, which can give a more realistic estimate of radiation exposure dose for patients undergoing CT examinations. Establishing hospital’s own DRL according to CTDIvol and SSDE is very important even though the radiation dose is lower than the national DRLs.
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Affiliation(s)
- Xiaoyan Hu
- Department of Radiology, Chengdu First People’s Hospital, Chengdu, Sichuan Province, China
| | - Jie Gou
- Department of Radiology, Chengdu First People’s Hospital, Chengdu, Sichuan Province, China
| | - Wei Lin
- Department of Radiology, Chengdu First People’s Hospital, Chengdu, Sichuan Province, China
| | - Chunhua Zou
- Department of Radiology, Chengdu First People’s Hospital, Chengdu, Sichuan Province, China
| | - Wenbo Li
- Department of Radiology, Chengdu First People’s Hospital, Chengdu, Sichuan Province, China
- * E-mail:
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Kiapour M, Ebrahimnejad Gorji K, Mehraeen R, Ghaemian N, Niksirat Sustani F, Abedi-Firouzjah R, Shabestani Monfared A. Can Common Lead Apron in Testes Region Cause Radiation Dose Reduction during Chest CT Scan? A Patient Study. J Biomed Phys Eng 2021; 11:497-504. [PMID: 34458197 PMCID: PMC8385221 DOI: 10.31661/jbpe.v0i0.2104-1307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Computed tomography (CT) is a routine procedure for diagnosing using ionization radiation which has hazardous effects especially on sensitive organs. OBJECTIVE The aim of this study was to quantify the dose reduction effect of lead apron shielding on the testicular region during routine chest CT scans. MATERIAL AND METHODS In this measurement study, the routine chest CT examinations were performed for 30 male patients with common lead aprons folded and positioned in testis regions. The patient's mean body mass index (BMI) was 26.2 ± 4.6 kg/m2. To calculate the doses at testis region, three thermoluminescent dosimeters (TLD-100) were attached at the top surface of the apron as an indicator of the doses without shielding, and three TLDs under the apron for doses with shielding. The TLD readouts were compared using SPSS software (Wilcoxon test) version 16. RESULTS The radiation dose in the testicular regions was reduced from 0.46 ± 0.04 to 0.20 ± 0.04 mGy in the presence of lead apron shielding (p < 0.001), the reduction was equal to 56%. Furthermore, the heritable risk probability was obtained at 2.0 ×10-5 % and 4.6 ×10-5 % for the patients using the lead apron shield versus without shield, respectively. CONCLUSION Applying common lead aprons as shielding in the testis regions of male patients undergoing chest CT scans can reduce the radiation doses significantly. Therefore, this shield can be recommended for routine chest CT examinations.
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Affiliation(s)
- Mohammad Kiapour
- MSc, Student Research Committee, Babol University of Medical Sciences, Babol, Iran
| | - Kourosh Ebrahimnejad Gorji
- PhD, Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Rahele Mehraeen
- MD, Department of Pediatric Radiology, Babol University of Medical Sciences, Babol, Iran
| | - Naser Ghaemian
- MD, Department of Radiology and Radiotherapy, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Fatemeh Niksirat Sustani
- MSc, Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Razzagh Abedi-Firouzjah
- MSc, Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Ali Shabestani Monfared
- PhD, Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
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Establishment of Objective Clinical Parameters for Assessment of Trigonocephaly: Are Caliper-Derived Clinical Measures Adequate? J Craniofac Surg 2021; 33:259-263. [PMID: 34334742 DOI: 10.1097/scs.0000000000008061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE Objective clinical parameters characterizing the severity of trigonocephaly are essential given the concern for computerized tomography (CT) scans and radiation in infants. The present study seeks to develop a clinical tool by which to characterize trigonocephaly. DESIGN Retrospective cohort study. SETTING Tertiary academically affiliated children's medical center. PARTICIPANTS A retrospective review identified patients with trigonocephaly for whom surgery was recommended (group 1) and those with metopic ridging without significant trigonocephaly (group 2). Normal age-matched controls were also evaluated (group 3). INTERVENTIONS Cranial vault caliper measurements were compared across groups. Two ratios measuring anterior vault constriction were developed: (1) bitemporal width at the mid-forehead to the biparietal width, and (2) bitemporal width at the lateral brow to the biparietal width. MAIN OUTCOME MEASURES Bitemporal width to biparietal width (ratio). RESULTS Caliper measures were obtained from 19 patients in group 1, 8 patients in group 2, and 19 patients in group 3 (controls). Cranial indices were not significantly different across groups. The bitemporal width at the mid-forehead to the biparietal width ratio was significantly lower in group 1, with no difference between groups 2 and 3. The bitemporal width at the lateral brow to the biparietal width ratio was significantly different between all 3 groups, with group 1 < group 2 < group 3, respectively. CONCLUSIONS Bitemporal to biparietal ratios are a quantitative, objective clinical measure that can be used to differentiate patients with significant trigonocephaly from those with metopic ridging but no significant cranial deformity. These findings suggest that caliper-derived indices can assist in characterizing surgically relevant cranial vault deformities secondary to metopic synostosis and may circumvent CT-based analysis.
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Chi J, Ji YD, Shen L, Yin SN, Ding N, Chen XF, Xu DF. Low-dose CT of paediatric paranasal sinus using an ultra-low tube voltage (70 kVp) combined with the flash technique. Clin Radiol 2020; 76:77.e17-77.e21. [PMID: 32950256 DOI: 10.1016/j.crad.2020.08.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 08/20/2020] [Indexed: 10/23/2022]
Abstract
AIM To evaluate the radiation dose and diagnostic image quality of low-dose computed tomography (CT) of the paranasal sinus in children, with acquisition at an ultra-low tube voltage (70 kVp) combined with the Flash technique. MATERIALS AND METHODS Eighty paediatric patients underwent CT of the paranasal sinus and were divided into two groups according to different protocols (group A: 80 kVp protocol with conventional spiral mode [n=40] and group B: 70 kVp protocol with Flash scan mode [n=40]). For each examination, the CT dose index (CTDIvol), dose-length product (DLP), and effective dose (ED) were estimated. The image noise, signal-to-noise ratio (SNR), and overall subjective diagnostic image quality were also evaluated. RESULTS For radiation dose, the CTDIvol (mGy), DLP (mGy·cm), and ED (mSv) values of the 70 kVp protocol were significantly lower than those of the 80 kVp protocol (CTDIvol: 1.57±0.009 versus 0.39±0.004 mGy, p<0.001; DLP: 19.88±2.01 versus 6.31±0.52 mGy·cm, p<0.001; ED: 0.079±0.016 versus 0.024±0.005 mSv, p<0.001). Compared with those of the 80-kVp protocol, the image noise increased by 40.7% (p=0.113), the SNRsoft-tissue decreased by 48.9%, and the SNRbone increased by 10.1% with the 70-kVp protocol (p=0.176 and 0.227, respectively). There was no significant difference in the overall subjective image quality grades between these two groups (p=0.15). CONCLUSION When imaging the paranasal sinus in children, an ultra-low tube voltage (70 kVp) combined with the Flash CT technique can reduce the radiation dose significantly while maintaining diagnostic image quality with clinically acceptable image noise.
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Affiliation(s)
- J Chi
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - Y-D Ji
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - L Shen
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - S-N Yin
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - N Ding
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - X-F Chen
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China
| | - D-F Xu
- Department of Radiology, First People's Hospital of Wujiang District, Wujiang, Jiangsu 215200, China.
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Zhang H, Hu Y, Zhu Y, Chen X. Facing the SARS-CoV-2 Outbreak: What Should Obstetricians and Gynecologists Do? Disaster Med Public Health Prep 2020; 14:e19-e21. [PMID: 32713389 PMCID: PMC7445447 DOI: 10.1017/dmp.2020.263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/25/2020] [Accepted: 07/10/2020] [Indexed: 11/06/2022]
Abstract
An outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. In this major outbreak, women are a special group, especially pregnant patients. Many problems faced by clinicians are still unclear and need to be solved. As the largest obstetrics and gynecology hospital in North China, here we summarize the diagnosis and treatment process and key points of obstetrics and gynecology patients in our hospital during the period of the COVID-19 pandemic, hoping to provide available information to inform care of obstetrics and gynecology patients.
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Affiliation(s)
- Hongyuan Zhang
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Department of Gynecology, Tianjin Central Gynecology and Obstetrics Hospital, Nankai University, Tianjin, China
| | - Yuanjing Hu
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Department of Gynecology, Tianjin Central Gynecology and Obstetrics Hospital, Nankai University, Tianjin, China
| | - Yingjun Zhu
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Department of Gynecology, Tianjin Central Gynecology and Obstetrics Hospital, Nankai University, Tianjin, China
| | - Xu Chen
- Tianjin Key Laboratory of Human Development and Reproductive Regulation, Department of Gynecology, Tianjin Central Gynecology and Obstetrics Hospital, Nankai University, Tianjin, China
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Abstract
The use of point-of-care ultrasound (POCUS) performed by non-radiologists has become more widespread and is entering new arenas of clinical care, particularly in the world of pediatrics. Children are prime candidates for ultrasound because they are more at risk to the harmful effects of ionizing radiation than adults. This is the second part of a two-part article reviewing 10 uses of POCUS that pediatricians can apply to their practice in both inpatient and outpatient settings. [Pediatr Ann. 2020;49(4):e196-e200.].
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15
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Unpaired Low-Dose CT Denoising Network Based on Cycle-Consistent Generative Adversarial Network with Prior Image Information. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2019; 2019:8639825. [PMID: 31885686 PMCID: PMC6925923 DOI: 10.1155/2019/8639825] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/02/2019] [Accepted: 09/16/2019] [Indexed: 01/22/2023]
Abstract
The widespread application of X-ray computed tomography (CT) in clinical diagnosis has led to increasing public concern regarding excessive radiation dose administered to patients. However, reducing the radiation dose will inevitably cause server noise and affect radiologists' judgment and confidence. Hence, progressive low-dose CT (LDCT) image reconstruction methods must be developed to improve image quality. Over the past two years, deep learning-based approaches have shown impressive performance in noise reduction for LDCT images. Most existing deep learning-based approaches usually require the paired training dataset which the LDCT images correspond to the normal-dose CT (NDCT) images one-to-one, but the acquisition of well-paired datasets requires multiple scans, resulting the increase of radiation dose. Therefore, well-paired datasets are not readily available. To resolve this problem, this paper proposes an unpaired LDCT image denoising network based on cycle generative adversarial networks (CycleGAN) with prior image information which does not require a one-to-one training dataset. In this method, cyclic loss, an important trick in unpaired image-to-image translation, promises to map the distribution from LDCT to NDCT by using unpaired training data. Furthermore, to guarantee the accurate correspondence of the image content between the output and NDCT, the prior information obtained from the result preprocessed using the LDCT image is integrated into the network to supervise the generation of content. Given the map of distribution through the cyclic loss and the supervision of content through the prior image loss, our proposed method can not only reduce the image noise but also retain critical information. Real-data experiments were carried out to test the performance of the proposed method. The peak signal-to-noise ratio (PSNR) improves by more than 3 dB, and the structural similarity (SSIM) increases when compared with the original CycleGAN without prior information. The real LDCT data experiment demonstrates the superiority of the proposed method according to both visual inspection and quantitative evaluation.
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16
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Massimi L, Bianchi F, Frassanito P, Calandrelli R, Tamburrini G, Caldarelli M. Imaging in craniosynostosis: when and what? Childs Nerv Syst 2019; 35:2055-2069. [PMID: 31289853 DOI: 10.1007/s00381-019-04278-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 06/25/2019] [Indexed: 12/14/2022]
Abstract
PURPOSE Currently, the interest on craniosynostosis in the clinical practice is raised by their increased frequency and their genetic implications other than by the still existing search of less invasive surgical techniques. These reasons, together with the problem of legal issues, make the need of a definite diagnosis for a crucial problem, even in single-suture craniosynostosis (SSC). Although the diagnosis of craniosynostosis is primarily the result of physical examination, craniometrics measuring, and observation of the skull deformity, the radiological assessment currently plays an important role in the confirmation of the diagnosis, the surgical planning, and even the postoperative follow-up. On the other hand, in infants, the use of radiation or the need of sedation/anesthesia raises the problem to reduce them to minimum to preserve such a delicate category of patient from their adverse effects. METHODS, RESULTS AND CONCLUSIONS This review aims at summarizing the state of the art of the role of radiology in craniosynostosis, mainly focusing on indications and techniques, to provide an update not only to pediatric neurosurgeons or maxillofacial surgeons but also to all the other specialists involved in their management, like neonatologists, pediatricians, clinical geneticists, and pediatric neurologists.
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Affiliation(s)
- L Massimi
- Fondazione Policlinico Gemelli IRCCS, Neurochirurgia Infantile, Rome, Italy.
- Università Cattolica del Sacro Cuore, Istituto Neurochirurgia, Rome, Italy.
| | - F Bianchi
- Fondazione Policlinico Gemelli IRCCS, Neurochirurgia Infantile, Rome, Italy
| | - P Frassanito
- Fondazione Policlinico Gemelli IRCCS, Neurochirurgia Infantile, Rome, Italy
| | - R Calandrelli
- Polo scienze delle immagini, di laboratorio ed infettivologiche, Area diagnostica per immagini, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - G Tamburrini
- Fondazione Policlinico Gemelli IRCCS, Neurochirurgia Infantile, Rome, Italy
- Università Cattolica del Sacro Cuore, Istituto Neurochirurgia, Rome, Italy
| | - M Caldarelli
- Fondazione Policlinico Gemelli IRCCS, Neurochirurgia Infantile, Rome, Italy
- Università Cattolica del Sacro Cuore, Istituto Neurochirurgia, Rome, Italy
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Rawashdeh M, Abdelrahman M, Zaitoun M, Saade C, Alewaidat H, McEntee MF. Diagnostic reference levels for paediatric CT in Jordan. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:1060-1073. [PMID: 31469115 DOI: 10.1088/1361-6498/ab3ee2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This study aimed to investigate the current status of Diagnostic Reference Levels (DRLs) in paediatric CT across Jordan. The dose data for four main CT examinations (brain, chest, abdominopelvic, and chest, abdomen and pelvis (CAP)) in hospitals and imaging centres (n = 4) were measured. The volume CT dose index (CTDIvol) and Dose Length Product (DLP) values were compared within the different hospitals and age groups (<1 year, 1-4 years, 5-10 years and 11-18 years). DRLs in Jordan were compared to international DRLs. The paediatric population consisted of 1818 children; 61.4% of them were male. There were significant variations between the DRLs for each CT scanner with an up to four-fold difference in dose between hospitals. There were apparent significant differences between Jordan and other countries with the DLPs in Jordan being relatively high. However, for CTDIvol, the values in Jordan were close to those of other countries. This study confirmed variations in the CTDIvol and DLP values of paediatric CT scans in Jordan. These variations were attributed to the different protocols and equipment used. There is a need to optimise paediatric CT examinations doses in Jordan.
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Affiliation(s)
- Mohammad Rawashdeh
- Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, 222110, Jordan
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Choudhary N, Rana BS, Shukla A, Oinam AS, Singh NP, Kumar S. PATIENTS DOSE ESTIMATION IN CT EXAMINATIONS USING SIZE SPECIFIC DOSE ESTIMATES. RADIATION PROTECTION DOSIMETRY 2019; 184:256-262. [PMID: 30496523 DOI: 10.1093/rpd/ncy207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/30/2018] [Accepted: 11/06/2018] [Indexed: 06/09/2023]
Abstract
The present work reports data of radiation exposure to the patients during head, chest, pelvis and abdomen CT examinations performed on a third-generation 16-slice CT machine. Radiation exposure was estimated using size specific dose estimates (SSDE) method, which takes into account patient's physical dimensions in phantom measured computed tomography dose index (CTDI) value. The reported median CT dose volume index CTDIvol values in head, chest, pelvis and abdomen examinations were 26.76, 16.27, 29.81 and 14.74 mGy, respectively. The median doses evaluated using SSDE methodology for the above mentioned procedure were 54.1, 23.1, 42.8 and 20.1 mGy, respectively. Our results showed variation in dose values estimated using CTDI and SSDE methods in all examinations. The evaluated SSDE values were also compared to the values derived from data reported by the American Association of Physicist in Medicine (AAPM). SSDE values in present measurements are 4-8% lower than AAPM values. The present results show that CTDI parameters recorded on CT console should not be used to specify patient dose during CT procedures.
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Affiliation(s)
- Neha Choudhary
- Department of Radiotherapy, Shanti Mukand Hospita, New Delhi, India
| | | | - Arvind Shukla
- Department of Radiotherapy, R. N. T Medical College, Udaipur, India
| | | | | | - Sanjeev Kumar
- Department of Physics, G. G. D. S. D. College, Chandigarh, India
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Impact of the Image Gently® Campaign on Computerized Tomography Use for Evaluation of Pediatric Nephrolithiasis. J Urol 2019; 201:996-1004. [PMID: 30694933 DOI: 10.1097/ju.0000000000000030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The Image Gently® campaign was launched by several radiological societies in 2007 to promote safe imaging in children. A goal of the campaign was to reduce ionizing radiation exposure in children. Given the recurrent nature of kidney stones, affected children are at risk for unnecessary ionizing radiation exposure from computerized tomography. We sought to determine whether the Image Gently campaign led to a decrease in the use of computerized tomography for evaluating children with nephrolithiasis. We hypothesized that the campaign was the primary cause of a reduction in the use of computerized tomography. MATERIALS AND METHODS We analyzed medical claims data from 2001 to 2015 identifying children with nephrolithiasis covered by the same commercial insurance provider. Using a difference in differences design, we estimated changes in computerized tomography use after the campaign started among patients less than 18 years old compared to a control group age 18 years or older with nephrolithiasis. RESULTS We identified 12,734 children and 787,720 adults diagnosed with nephrolithiasis. Before 2007 quarterly rates of computerized tomography use during a stone episode (per 1,000 patients) were increasing at a parallel rate in children and adults (5.1 in children vs 7.2 in adults, p = 0.123). After the Image Gently campaign started the use of computerized tomography decreased in both groups but at a slightly higher rate in adults (difference in differences 2.96, 95% CI 0.00 to 5.91, p = 0.050). CONCLUSIONS Although there has been a reduction in the use of computerized tomography among children with nephrolithiasis, given a similar trend seen in adults this change cannot be primarily attributed to the Image Gently campaign.
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Pediatric CT radiation exposure: where we were, and where we are now. Pediatr Radiol 2019; 49:469-478. [PMID: 30923878 DOI: 10.1007/s00247-018-4281-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/24/2018] [Accepted: 10/05/2018] [Indexed: 01/01/2023]
Abstract
Since the turn of the last millennium, the pediatric radiology community has blazed a patient-quality and safety trail in helping to effectively address the public and the news media's concerns about the implications of ionizing radiation from CT scanners in children. As such, this article (1) reviews the potential deleterious effects of ionizing radiation, (2) discusses why limiting radiation exposure in children is so important, (3) tells the history of pediatric CT radiation exposure concerns, (4) explains the interventions that took place to address these concerns and (5) touches on the current school of thought on pediatric CT dose reduction.
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21
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Teferi S, Zewdeneh D, Bekele S. Pediatric Residents' and Medical Interns' Awareness about Pediatric Ionizing Radiation Dose from Computed Tomography and Its Associated Risks in Tertiary Hospital in Ethiopia. Ethiop J Health Sci 2019; 28:383-392. [PMID: 30607051 PMCID: PMC6308742 DOI: 10.4314/ejhs.v28i4.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Background The international literature on physicians' knowledge regarding radiation dosages and risks due to computed tomography showed a widespread underestimation of diagnostic radiation doses. Hence, the objective of this work is to assess the awareness of pediatric residents and medical interns about pediatric CT dose and possible risks. Methods A cross-sectional study was conducted on May/2016 among year I to year III pediatric residents and 2015/2016 year medical interns attaching Pediatrics Department during the study period in Tikur Anbessa Specialized Referral and Teaching Hospital. Data was collected by distributing standardized structured questionnaires. Finally, after the data was checked for clarity and completeness, it was analyzed by using SPSS software. Result While the majority (76.3%) of the residents and interns knew that children were more sensitive to radiation than adults, 93.7% did not know that there is currently no annual dose limit set for medical exposure of patients. The majority of the respondents (81.3%) know the risk of cancer from CT scan, but most (60%) of the respondents did not know that many imaging facilities still use adult doses for pediatric patients. Furthermore, 18.8% thought that magnetic resonance imaging involves ionizing radiation, and 8.9% of the physicians associated ultrasound examinations with ionizing radiation. Conclusion Within resident group, since the level of clinical experience did not affect the outcome, we recommend that formal education and training on awareness of radiation with special concern on pediatric population is mandatory especially for pediatric residents and pediatricians who are major caretakers of children.
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Affiliation(s)
- Seife Teferi
- Department of Radiology, College of Health Sciences, Addis Ababa University
| | - Daniel Zewdeneh
- Department of Radiology, College of Health Sciences, Addis Ababa University
| | - Solomon Bekele
- Department of Radiology, College of Health Sciences, Addis Ababa University
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Spampinato MV, Stalcup S, Matheus MG, Byington K, Tyler M, Bickley S, Tipnis S. RADIATION DOSE AND IMAGE QUALITY IN PEDIATRIC HEAD CT. RADIATION PROTECTION DOSIMETRY 2018; 182:310-316. [PMID: 30590841 DOI: 10.1093/rpd/ncy066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 04/10/2018] [Indexed: 06/09/2023]
Abstract
Our goal was to define a pediatric head CT protocol able to provide images of diagnostic quality, using the least amount of radiation, in children <10 years of age, while using a filtered back projection reconstruction algorithm. Image quality of 119 pediatric head CTs was assessed using a 5-point scoring system. Exams with scores ≥2.5 were considered of sufficient diagnostic quality. The contrast-to-noise ratio (CNR) was also measured. For children <1 year and 1-9 years, all studies performed with CTDIvol ≥ 20.1 mGy (range: 9-46 mGy) and CTDIvol ≥ 27.5 mGy (range: 15-60 mGy) yielded images of diagnostic quality. All diagnostic studies had a minimum CNR of 1.4. These CTDIvol values represent a good balance between image quality and radiation burden. This information can be helpful in designing pediatric head CT protocols with further dose-reduction, namely, iterative reconstruction algorithms and automated exposure control.
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Affiliation(s)
- Maria Vittoria Spampinato
- Department of Radiology and Radiological Science, Medical University of South Carolina, 96 Jonathan Lucas Street, MSC 323, Charleston, SC, USA
| | - Seth Stalcup
- Department of Radiology and Radiological Science, Medical University of South Carolina, 96 Jonathan Lucas Street, MSC 323, Charleston, SC, USA
| | - Maria Gisele Matheus
- Department of Radiology and Radiological Science, Medical University of South Carolina, 96 Jonathan Lucas Street, MSC 323, Charleston, SC, USA
| | | | - Michael Tyler
- College of Medicine, Medical University of South Carolina, 96 Jonathan Lucas Street, Charleston, SC, USA
| | - Stetson Bickley
- Department of Radiology, Virginia Tech Carilion School of Medicine, 2 Riverside Circle, Roanoke, VA, USA
| | - Sameer Tipnis
- Department of Radiology and Radiological Science, Medical University of South Carolina, 96 Jonathan Lucas Street, MSC 323, Charleston, SC, USA
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Itri JN, Raghavan K, Patel SB, Broder JC, Tierney S, Gray D, Burleson J, MacDonald S, Seidenwurm DJ. Developing Quality Measures for Diagnostic Radiologists: Part 2. J Am Coll Radiol 2018; 15:1366-1384. [DOI: 10.1016/j.jacr.2018.05.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 04/23/2018] [Accepted: 05/05/2018] [Indexed: 12/21/2022]
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Zhang Y, Lu H, Rong J, Meng J, Shang J, Ren P, Zhang J. Adaptive non-local means on local principle neighborhood for noise/artifacts reduction in low-dose CT images. Med Phys 2018; 44:e230-e241. [PMID: 28901609 DOI: 10.1002/mp.12388] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 02/24/2017] [Accepted: 04/27/2017] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Low-dose CT (LDCT) technique can reduce the x-ray radiation exposure to patients at the cost of degraded images with severe noise and artifacts. Non-local means (NLM) filtering has shown its potential in improving LDCT image quality. However, currently most NLM-based approaches employ a weighted average operation directly on all neighbor pixels with a fixed filtering parameter throughout the NLM filtering process, ignoring the non-stationary noise nature of LDCT images. In this paper, an adaptive NLM filtering scheme on local principle neighborhoods (PC-NLM) is proposed for structure-preserving noise/artifacts reduction in LDCT images. METHODS Instead of using neighboring patches directly, in the PC-NLM scheme, the principle component analysis (PCA) is first applied on local neighboring patches of the target patch to decompose the local patches into uncorrelated principle components (PCs), then a NLM filtering is used to regularize each PC of the target patch and finally the regularized components is transformed to get the target patch in image domain. Especially, in the NLM scheme, the filtering parameter is estimated adaptively from local noise level of the neighborhood as well as the signal-to-noise ratio (SNR) of the corresponding PC, which guarantees a "weaker" NLM filtering on PCs with higher SNR and a "stronger" filtering on PCs with lower SNR. The PC-NLM procedure is iteratively performed several times for better removal of the noise and artifacts, and an adaptive iteration strategy is developed to reduce the computational load by determining whether a patch should be processed or not in next round of the PC-NLM filtering. RESULTS The effectiveness of the presented PC-NLM algorithm is validated by experimental phantom studies and clinical studies. The results show that it can achieve promising gain over some state-of-the-art methods in terms of artifact suppression and structure preservation. CONCLUSIONS With the use of PCA on local neighborhoods to extract principal structural components, as well as adaptive NLM filtering on PCs of the target patch using filtering parameter estimated based on the local noise level and corresponding SNR, the proposed PC-NLM method shows its efficacy in preserving fine anatomical structures and suppressing noise/artifacts in LDCT images.
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Affiliation(s)
- Yuanke Zhang
- School of Biomedical Engineering, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China.,School of Information Science and Engineering, Qufu Normal University, Rizhao, Shandong, 276826, China
| | - Hongbing Lu
- School of Biomedical Engineering, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Junyan Rong
- School of Biomedical Engineering, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Jing Meng
- School of Information Science and Engineering, Qufu Normal University, Rizhao, Shandong, 276826, China
| | - Junliang Shang
- School of Information Science and Engineering, Qufu Normal University, Rizhao, Shandong, 276826, China
| | - Pinghong Ren
- School of Information Science and Engineering, Qufu Normal University, Rizhao, Shandong, 276826, China
| | - Junying Zhang
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
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Bhatt S, Srivastava AK, Meena N, Thakur S. Appraisal of radiation dose with 64-slice computed tomography perfusion in lung cancer patients with special reference to SSDE: An initial experience in a tertiary care hospital. Indian J Radiol Imaging 2018; 27:389-396. [PMID: 29379232 PMCID: PMC5761164 DOI: 10.4103/ijri.ijri_44_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Context: Computed tomography perfusion (CTP) is an important functional tool for lung cancer. It is expected to deliver high radiation dose, making its accurate estimation important. Size-specific dose estimate (SSDE) is a new dose metric, which includes the scanner output as well as the patient size. Aims: To determine radiation dose [CT dose index (CTDIvol), dose length product (DLP), effective dose (ED), and SSDE] for CTP in lung cancer and the correlation of CTDIvol, DLP, and SSDE with effective diameter and SSDE with weight, body mass index (BMI), and the scan length. Settings and Design: Cross-sectional study in the Department of Radio-diagnosis from October 2015 to March 2016. Patients and Methods: Due ethical approval and informed consent was taken. Thirty consecutive adult patients of lung cancer undergoing CTP study were included; various radiation dose parameters were determined and presented as mean ± SD. Statistical Analysis Used: Paired Student's t-test and Pearson correlation using Statistical Package for the Social Sciences, Version 16. Results: Mean radiation dose was CTDIvol = 270.138 ± 1.627 mGy, DLP = 681 ± 53.496 mGy.cm, ED = 12.501 ± 0.923 mSv, SSDE = 388.90 ± 81.27 mGy. The CTDIvol and DLP had significant positive correlation (r = 0.556, P = 0.000 and r = 0.522, P = 0.003, respectively) with effective diameter. SSDE had strong negative correlation (r = −0.997, P = 0.000) with effective diameter, significant negative correlation with the BMI (r = −0.889; P = 0.000) and weight (r = −0.910, P = 0.000) of patients. Scan length was not significantly correlated in SSDE (r = −0.012, P = 0.951). Conclusions: Smaller sized patients had greater SSDE.
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Affiliation(s)
- Shuchi Bhatt
- Department of Radio-diagnosis, University College of Medical Sciences and Guru Teg Bahadur Hospital, New Delhi, India
| | - Ajai K Srivastava
- Department of Radio-diagnosis, University College of Medical Sciences and Guru Teg Bahadur Hospital, New Delhi, India
| | - Neha Meena
- Department of Radio-diagnosis, University College of Medical Sciences and Guru Teg Bahadur Hospital, New Delhi, India
| | - Shweta Thakur
- Department of Radio-diagnosis, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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Zhang Y, Rong J, Lu H, Xing Y, Meng J. Low-Dose Lung CT Image Restoration Using Adaptive Prior Features From Full-Dose Training Database. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:2510-2523. [PMID: 28961108 DOI: 10.1109/tmi.2017.2757035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The valuable structure features in full-dose computed tomography (FdCT) scans can be exploited as prior knowledge for low-dose CT (LdCT) imaging. However, lacking the capability to represent local characteristics of interested structures of the LdCT image adaptively may result in poor preservation of details/textures in LdCT image. This paper aims to explore a novel prior knowledge retrieval and representation paradigm, called adaptive prior features assisted restoration algorithm, for the purpose of better restoration of the low-dose lung CT images by capturing local features from FdCT scans adaptively. The innovation lies in the construction of an offline training database and the online patch-search scheme integrated with the principal components analysis (PCA). Specifically, the offline training database is composed of 3-D patch samples extracted from existing full-dose lung scans. For online patch-search, 3-D patches with structure similar to the noisy target patch are first selected from the database as the training samples. Then, PCA is applied on the training samples to retrieve their local prior principal features adaptively. By employing the principal features to decompose the noisy target patch and using an adaptive coefficient shrinkage technique for inverse transformation, the noise of the target patch can be efficiently removed and the detailed texture can be well preserved. The effectiveness of the proposed algorithm was validated by CT scans of patients with lung cancer. The results show that it can achieve a noticeable gain over some state-of-the-art methods in terms of noise suppression and details/textures preservation.
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Ney MSCJ, Dos Santos AASMD, Fonseca GIVDS, Lodi CS. EFFECTIVE DOSES RADIATION TO THE PATIENTS IN EXAMINATIONS PERFORMED IN THREE CT SCANNERS IN BRAZIL. RADIATION PROTECTION DOSIMETRY 2017; 176:444-449. [PMID: 28383681 DOI: 10.1093/rpd/ncx030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/23/2017] [Indexed: 06/07/2023]
Abstract
This work aimed to analyze the effective doses radiation, estimated from the dose-length product, in 4821 examinations carried out in three CT scanners (named as A, B and C) during the period of December 1st 2013 to 30th November 2014 and compare them, with 95% confidence interval, with typical values for the CT practice described in the American Association of Physicists in Medicine (AAPM) Report # 96 (2008). The mean values of effective doses found in the A, B and C equipments were, respectively, 1.55, 2.09 and 1.30 mSv, in head; 7.75, 9.01 and 10.45 mSv in abdomen/pelvis; and 3.87, 7.94 and 3.92 mSv in chest examinations. There were significantly different among each service, except between the A and C equipments in the chest examinations (p = 0.7148). Only the B equipment performed CT scans with effective doses above the US typical values, for head and chest examinations.
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Affiliation(s)
- Mônica Silva Costa Janson Ney
- Radiology Service of the Marcilio Dias Navy Hospital (HNMD), Federal Fluminense University (UFF), Rio de Janeiro-RJ,Brazil
| | | | | | - Caio Silva Lodi
- Medical School of the Federal Fluminense University (UFF), Niterói-RJ, Brazil
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An improved statistical iterative algorithm for sparse-view and limited-angle CT image reconstruction. Sci Rep 2017; 7:10747. [PMID: 28878293 PMCID: PMC5587589 DOI: 10.1038/s41598-017-11222-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/21/2017] [Indexed: 12/04/2022] Open
Abstract
Because radiation is harmful to patients, it is important to reduce X-ray exposure in the clinic. For CT, reconstructions from sparse views or limited angle tomography are being used more frequently for low dose imaging. However, insufficient sampling data causes severe streak artifacts in images reconstructed using conventional methods. To solve this issue, various methods have recently been developed. In this paper, we improve a statistical iterative algorithm based on the minimization of the image total variation (TV) for sparse or limited projection views during CT image reconstruction. Considering the statistical nature of the projection data, the TV is performed under a penalized weighted least-squares (PWLS-TV) criterion. During implementation of the proposed method, the image reconstructed using the filtered back-projection (FBP) method is used as the initial value of the first iteration. Next, the feature refinement (FR) step is performed after each PWLS-TV iteration to extract the fine features lost in the TV minimization, which we refer to as ‘PWLS-TV-FR’.
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Mokhtar A, Elawdy M, El-Hamid MA, Refaie H, El-Diasty TA, Mogy SE. Radiation dose associated with common computed tomography examination. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2017. [DOI: 10.1016/j.ejrnm.2017.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Bodelle B, Fischbach C, Booz C, Yel I, Frellesen C, Kaup M, Beeres M, Vogl TJ, Scholtz JE. Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality. Pediatr Radiol 2017; 47:831-837. [PMID: 28352977 DOI: 10.1007/s00247-017-3813-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/22/2016] [Accepted: 02/15/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. OBJECTIVE To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. MATERIALS AND METHODS Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. RESULTS Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). CONCLUSION Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration.
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Affiliation(s)
- Boris Bodelle
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
| | - Constanze Fischbach
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Christian Booz
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Ibrahim Yel
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Claudia Frellesen
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Moritz Kaup
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Martin Beeres
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Jan-Erik Scholtz
- Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
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Parisi MT, Bermo MS, Alessio AM, Sharp SE, Gelfand MJ, Shulkin BL. Optimization of Pediatric PET/CT. Semin Nucl Med 2017; 47:258-274. [PMID: 28417855 DOI: 10.1053/j.semnuclmed.2017.01.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PET/CT, the most common form of hybrid imaging, has transformed oncologic imaging and is increasingly being used for nononcologic applications as well. Performing PET/CT in children poses unique challenges. Not only are children more sensitive to the effects of radiation than adults but, following radiation exposure, children have a longer postexposure life expectancy in which to exhibit adverse radiation effects. Both the PET and CT components of the study contribute to the total patient radiation dose, which is one of the most important risks of the study in this population. Another risk in children, not typically encountered in adults, is potential neurotoxicity related to the frequent need for general anesthesia in this patient population. Optimizing pediatric PET/CT requires making improvements to both the PET and the CT components of the procedure while decreasing the potential for risk. This can be accomplished through judicious performance of imaging, the use of recommended pediatric 18fluorine-2-fluoro-2-deoxy-d-glucose (18F-FDG) administered activities, thoughtful selection of pediatric-specific CT imaging parameters, careful patient preparation, and use of appropriate patient immobilization. In this article, we will review a variety of strategies for radiation dose optimization in pediatric 18F-FDG-PET/CT focusing on these processes. Awareness of and careful selection of pediatric-specific CT imaging parameters designed for appropriate diagnostic, localization, or attenuation correction only CT, in conjunction with the use of recommended radiotracer administered activities, will help to ensure image quality while limiting patient radiation exposure. Patient preparation, an important determinant of image quality, is another focus of this review. Appropriate preparative measures are even more crucial in children in whom there is a higher incidence of brown fat, which can interfere with study interpretation. Finally, we will discuss measures to improve the patient experience, the resource use, the departmental workflow, and the diagnostic performance of the study through the use of appropriate technology, all in the context of minimizing procedure-related risks.
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Affiliation(s)
- Marguerite T Parisi
- Departments of Radiology, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, WA; Departments of Pediatrics, University of Washington School of Medicine and Seattle Children's Hospital, Seattle, WA.
| | - Mohammed S Bermo
- Department of Nuclear Medicine, University of Washington School of Medicine, Seattle, WA
| | - Adam M Alessio
- Departments of Radiology, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, WA
| | - Susan E Sharp
- Departments of Radiology, University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinatti, OH
| | - Michael J Gelfand
- Departments of Radiology, University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinatti, OH
| | - Barry L Shulkin
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN
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Radiation dose affected by mammographic composition and breast size: first application of a radiation dose management system for full-field digital mammography in Korean women. World J Surg Oncol 2017; 15:38. [PMID: 28153022 PMCID: PMC5290600 DOI: 10.1186/s12957-017-1107-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/25/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Relative to Western women, Korean women show several differences in breast-related characteristics, including higher rates of dense breasts and small breasts. We investigated how mammographic composition and breast size affect the glandular dose during full-field digital mammography (FFDM) in Korean women using a radiation dose management system. METHODS From June 1 to June 30, 2015, 2120 FFDM images from 560 patients were acquired and mammographic breast composition and breast size were assessed. We analyzed the correlations of patient age, peak kilovoltage (kVp), current (mAs), compressed breast thickness, compression force, mammographic breast composition, and mammographic breast size with the mean glandular dose (MGD) of the breast using a radiation dose management system. The causes of increased radiation were investigated, among patients with radiation doses above the diagnostic reference level (4th quartile, ≥75%). RESULTS The MGD per view of 2120 images was 1.81 ± 0.70 mGy. In multivariate linear regression analysis, age was negatively associated with MGD (p < 0.05). The mAs, kVp, compressed breast thickness, and mammographic breast size were positively associated with MGD (p < 0.05). The "dense" group had a significantly higher MGD than the "non-dense" group (p < 0.05). Patients with radiation dose values above the diagnostic reference value had large breasts of dense composition. CONCLUSIONS Among Korean women, patients with large and dense breasts should be more carefully managed to ensure that a constant radiation dose is maintained.
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Journy NMY, Lee C, Harbron RW, McHugh K, Pearce MS, Berrington de González A. Projected cancer risks potentially related to past, current, and future practices in paediatric CT in the United Kingdom, 1990-2020. Br J Cancer 2017; 116:109-116. [PMID: 27824812 PMCID: PMC5220140 DOI: 10.1038/bjc.2016.351] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/12/2016] [Accepted: 09/25/2016] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND To project risks of developing cancer and the number of cases potentially induced by past, current, and future computed tomography (CT) scans performed in the United Kingdom in individuals aged <20 years. METHODS Organ doses were estimated from surveys of individual scan parameters and CT protocols used in the United Kingdom. Frequencies of scans were estimated from the NHS Diagnostic Imaging Dataset. Excess lifetime risks (ELRs) of radiation-related cancer were calculated as cumulative lifetime risks, accounting for survival probabilities, using the RadRAT risk assessment tool. RESULTS In 2000-2008, ELRs ranged from 0.3 to 1 per 1000 head scans and 1 to 5 per 1000 non-head scans. ELRs per scan were reduced by 50-70% in 2000-2008 compared with 1990-1995, subsequent to dose reduction over time. The 130 750 scans performed in 2015 in the United Kingdom were projected to induce 64 (90% uncertainty interval (UI): 38-113) future cancers. Current practices would lead to about 300 (90% UI: 230-680) future cancers induced by scans performed in 2016-2020. CONCLUSIONS Absolute excess risks from single exposures would be low compared with background risks, but even small increases in annual CT rates over the next years would substantially increase the number of potential subsequent cancers.
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Affiliation(s)
- Neige M Y Journy
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, MSC 9776, Bethesda, Maryland 20892, USA
| | - Choonsik Lee
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, MSC 9776, Bethesda, Maryland 20892, USA
| | - Richard W Harbron
- Institute of Health & Society, Newcastle University, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-upon-Tyne NE1 4LP, UK
- NIHR Health Protection Research Unit in Chemical and Radiation Threats and Hazards, Newcastle University, Newcastle-upon-Tyne, UK
| | - Kieran McHugh
- Great Ormond Street Hospital for Children, Great Ormond Street, London WC1N 3JH, UK
| | - Mark S Pearce
- Institute of Health & Society, Newcastle University, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-upon-Tyne NE1 4LP, UK
- NIHR Health Protection Research Unit in Chemical and Radiation Threats and Hazards, Newcastle University, Newcastle-upon-Tyne, UK
| | - Amy Berrington de González
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, MSC 9776, Bethesda, Maryland 20892, USA
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Liu R, He L, Luo Y, Yu H. Singular value decomposition-based 2D image reconstruction for computed tomography. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2017; 25:113-134. [PMID: 27834789 DOI: 10.3233/xst-16173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Singular value decomposition (SVD)-based 2D image reconstruction methods are developed and evaluated for a broad class of inverse problems for which there are no analytical solutions. The proposed methods are fast and accurate for reconstructing images in a non-iterative fashion. The multi-resolution strategy is adopted to reduce the size of the system matrix to reconstruct large images using limited memory capacity. A modified high-contrast Shepp-Logan phantom, a low-contrast FORBILD head phantom, and a physical phantom are employed to evaluate the proposed methods with different system configurations. The results show that the SVD methods can accurately reconstruct images from standard scan and interior scan projections and that they outperform other benchmark methods. The general SVD method outperforms the other SVD methods. The truncated SVD and Tikhonov regularized SVD methods accurately reconstruct a region-of-interest (ROI) from an internal scan with a known sub-region inside the ROI. Furthermore, the SVD methods are much faster and more flexible than the benchmark algorithms, especially in the ROI reconstructions in our experiments.
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Affiliation(s)
- Rui Liu
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, USA
- Department of Biomedical Engineering, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Lu He
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, USA
| | - Yan Luo
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, USA
| | - Hengyong Yu
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, USA
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Power SP, Moloney F, Twomey M, James K, O’Connor OJ, Maher MM. Computed tomography and patient risk: Facts, perceptions and uncertainties. World J Radiol 2016; 8:902-915. [PMID: 28070242 PMCID: PMC5183924 DOI: 10.4329/wjr.v8.i12.902] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/29/2016] [Accepted: 10/24/2016] [Indexed: 02/06/2023] Open
Abstract
Since its introduction in the 1970s, computed tomography (CT) has revolutionized diagnostic decision-making. One of the major concerns associated with the widespread use of CT is the associated increased radiation exposure incurred by patients. The link between ionizing radiation and the subsequent development of neoplasia has been largely based on extrapolating data from studies of survivors of the atomic bombs dropped in Japan in 1945 and on assessments of the increased relative risk of neoplasia in those occupationally exposed to radiation within the nuclear industry. However, the association between exposure to low-dose radiation from diagnostic imaging examinations and oncogenesis remains unclear. With improved technology, significant advances have already been achieved with regards to radiation dose reduction. There are several dose optimization strategies available that may be readily employed including omitting unnecessary images at the ends of acquired series, minimizing the number of phases acquired, and the use of automated exposure control as opposed to fixed tube current techniques. In addition, new image reconstruction techniques that reduce radiation dose have been developed in recent years with promising results. These techniques use iterative reconstruction algorithms to attain diagnostic quality images with reduced image noise at lower radiation doses.
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Li B, Lyu Q, Ma J, Wang J. Iterative reconstruction for CT perfusion with a prior-image induced hybrid nonlocal means regularization: Phantom studies. Med Phys 2016; 43:1688. [PMID: 27036567 DOI: 10.1118/1.4943380] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE In computed tomography perfusion (CTP) imaging, an initial phase CT acquired with a high-dose protocol can be used to improve the image quality of later phase CT acquired with a low-dose protocol. For dynamic regions, signals in the later low-dose CT may not be completely recovered if the initial CT heavily regularizes the iterative reconstruction process. The authors propose a hybrid nonlocal means (hNLM) regularization model for iterative reconstruction of low-dose CTP to overcome the limitation of the conventional prior-image induced penalty. METHODS The hybrid penalty was constructed by combining the NLM of the initial phase high-dose CT in the stationary region and later phase low-dose CT in the dynamic region. The stationary and dynamic regions were determined by the similarity between the initial high-dose scan and later low-dose scan. The similarity was defined as a Gaussian kernel-based distance between the patch-window of the same pixel in the two scans, and its measurement was then used to weigh the influence of the initial high-dose CT. For regions with high similarity (e.g., stationary region), initial high-dose CT played a dominant role for regularizing the solution. For regions with low similarity (e.g., dynamic region), the regularization relied on a low-dose scan itself. This new hNLM penalty was incorporated into the penalized weighted least-squares (PWLS) for CTP reconstruction. Digital and physical phantom studies were performed to evaluate the PWLS-hNLM algorithm. RESULTS Both phantom studies showed that the PWLS-hNLM algorithm is superior to the conventional prior-image induced penalty term without considering the signal changes within the dynamic region. In the dynamic region of the Catphan phantom, the reconstruction error measured by root mean square error was reduced by 42.9% in PWLS-hNLM reconstructed image. CONCLUSIONS The PWLS-hNLM algorithm can effectively use the initial high-dose CT to reconstruct low-dose CTP in the stationary region while reducing its influence in the dynamic region.
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Affiliation(s)
- Bin Li
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China and Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Qingwen Lyu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390 and Zhujiang Hospital, Southern Medical University, Guangdong 510280, China
| | - Jianhua Ma
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China
| | - Jing Wang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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Yu WY, Ho TS, Ko H, Chan WY, Ong S, Hui FKH. Reducing cranial computed tomography effective radiation dose by 30% using adaptive iterative dose reduction. PROCEEDINGS OF SINGAPORE HEALTHCARE 2016. [DOI: 10.1177/2010105816651655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Introduction: The use of computed tomography (CT) imaging as a diagnostic modality is increasing rapidly and CT is the dominant contributor to diagnostic medical radiation exposure. The aim of this project was to reduce the effective radiation dose to patients undergoing cranial CT examination, while maintaining diagnostic image quality. Methods: Data from a total of 1003, 132 and 27 patients were examined for three protocols: CT head, CT angiography (CTA), and CT perfusion (CTP), respectively. Following installation of adaptive iterative dose reduction (AIDR) 3D software, tube current was lowered in consecutive cycles, in a stepwise manner and effective radiation doses measured at each step. Results: Baseline effective radiation doses for CT head, CTA and CTP were 1.80, 3.60 and 3.96 mSv, at currents of 300, 280 and 130–150 mA, respectively. Using AIDR 3D and final reduced currents of 160, 190 and 70–100 mA for CT head, CTA and CTP gave effective doses of 1.29, 3.18 and 2.76 mSv, respectively. Conclusion: We demonstrated that satisfactory reductions in the effective radiation dose for CT head (28.3%), CTA (11.6%) and CTP (30.1%) can be achieved without sacrificing diagnostic image quality. We have also shown that iterative reconstruction techniques such as AIDR 3D can be effectively used to help reduce effective radiation dose. The dose reductions were performed within a short period and can be easily achievable, even in busy departments.
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Affiliation(s)
- Wai-Yung Yu
- Department of Neuroradiology, National Neuroscience Institute, Singapore
| | - Thye Sin Ho
- Department of Neuroradiology, National Neuroscience Institute, Singapore
| | - Henry Ko
- SingHealth Centre for Health Services Research, SingHealth, c/o SingHealth Office of Research, Singapore
- SingHealth & Duke-NUS Academic Medicine Research Institute, Duke-NUS Medical School, Singapore
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, Australia
| | - Wai-Yee Chan
- Department of Neuroradiology, National Neuroscience Institute, Singapore
| | - Serene Ong
- SingHealth & Duke-NUS Academic Medicine Research Institute, Duke-NUS Medical School, Singapore
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Anderson KT, Greenfield S, Putnam LR, Hamilton E, Kawaguchi A, Austin MT, Kao LS, John SD, Lally KP, Tsao K. Don't forget the dose: Improving computed tomography dosing for pediatric appendicitis. J Pediatr Surg 2016; 51:1944-1948. [PMID: 27692347 DOI: 10.1016/j.jpedsurg.2016.09.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 09/12/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND A pediatric computed tomography (CT) radiation dose reduction program was implemented throughout our children's associated hospital system in 2010. We hypothesized that the CT dose received for evaluation of appendicitis in children would be significantly higher among the 40 referral, nonmember hospitals (NMH) than the 9 member hospitals (MH). METHODS Preoperative CTs of pediatric (<18years) appendectomy patients between April 2012 and April 2015 were reviewed. Size specific dose estimate (SSDE), an approximation of absorbed dose incorporating patient diameter, and Effective Dose (ED) were calculated for each scan. RESULTS 1128 (65%) of 1736 appendectomy patients underwent preoperative CT. 936 patients seen at and 102 children evaluated at NMH had dosing and patient diameter data for analysis. SSDE and ED were significantly higher with greater variance at NMH across all ages (all p<0.05, Figure). NMH's SSDE and ED also exceeded reference levels. CONCLUSION Radiation exposure in CT scans for evaluation of pediatric appendicitis is significantly higher and more variable in NMH. A proactive approach to reduce dose, in addition to frequency, of CT scans in pediatric patients is essential. LEVEL OF EVIDENCE Level III.
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Affiliation(s)
- K Tinsley Anderson
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Susan Greenfield
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Luke R Putnam
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Emma Hamilton
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Akemi Kawaguchi
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Mary T Austin
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Lillian S Kao
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Susan D John
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - Kevin P Lally
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX
| | - KuoJen Tsao
- Center for Surgical Trials and Evidence-based Practice, Department of Pediatric Surgery at McGovern Medical School at The University of Texas Health Science Center at Houston and Children's Memorial Hermann Hospital, Houston, TX.
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Prospective ECG-gated high-pitch dual-source cardiac CT angiography in the diagnosis of congenital cardiovascular abnormalities: Radiation dose and diagnostic efficacy in a pediatric population. Diagn Interv Imaging 2016; 97:1141-1150. [DOI: 10.1016/j.diii.2016.03.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/19/2016] [Accepted: 03/25/2016] [Indexed: 11/21/2022]
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Marin JR, Lewiss RE. Point-of-care ultrasonography by pediatric emergency physicians. Policy statement. Ann Emerg Med 2016; 65:472-8. [PMID: 25805037 DOI: 10.1016/j.annemergmed.2015.01.028] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Indexed: 01/10/2023]
Abstract
Point-of-care ultrasonography is increasingly being used to facilitate accurate and timely diagnoses and to guide procedures. It is important for pediatric emergency physicians caring for patients in the emergency department to receive adequate and continued point-of-care ultrasonography training for those indications used in their practice setting. Emergency departments should have credentialing and quality assurance programs. Pediatric emergency medicine fellowships should provide appropriate training to physician trainees. Hospitals should provide privileges to physicians who demonstrate competency in point-of-care ultrasonography. Ongoing research will provide the necessary measures to define the optimal training and competency assessment standards. Requirements for credentialing and hospital privileges will vary and will be specific to individual departments and hospitals. As more physicians are trained and more research is completed, there should be one national standard for credentialing and privileging in point-of-care ultrasonography for pediatric emergency physicians.
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Smith EA, Dillman JR. Current role of body MRI in pediatric oncology. Pediatr Radiol 2016; 46:873-80. [PMID: 27229504 DOI: 10.1007/s00247-016-3560-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/06/2015] [Accepted: 01/21/2016] [Indexed: 12/18/2022]
Abstract
Magnetic resonance imaging (MRI) plays an important role in the imaging of children with non-central nervous system malignancies, and it is increasingly replacing or complementing CT in many cases. MRI has several advantages over CT, including superior contrast resolution as well as superior tissue characterization with the use of novel pulse sequences and functional or organ-specific contrast agents. In addition, the lack of ionizing radiation - an important consideration in children - allows for multiphase dynamic post-contrast imaging, which can be useful for lesion detection and characterization. Several challenges remain in the performance of MRI in pediatric oncology patients, including the frequent need for sedation or anesthesia in young children because of long imaging times, as well as the suboptimal imaging of the lungs in the evaluation for pulmonary metastatic disease. However, despite these challenges, with continued improvements in MRI image quality and the development of novel sequences, contrast agents and quantitative imaging techniques, MRI is expected to play an ever increasing role in the imaging of pediatric oncology patients.
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Affiliation(s)
- Ethan A Smith
- Department of Radiology, Section of Pediatric Radiology, University of Michigan Health System, C.S. Mott Children's Hospital, 1540 E. Hospital Drive, Ann Arbor, MI, 48109-4252, USA.
| | - Jonathan R Dillman
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Cumulative radiation exposure and estimated lifetime cancer risk in multiple-injury adult patients undergoing repeated or multiple CTs. Eur J Trauma Emerg Surg 2016; 44:19-27. [DOI: 10.1007/s00068-016-0665-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/14/2016] [Indexed: 10/22/2022]
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43
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Jang J, Jung SE, Jeong WK, Lim YS, Choi JI, Park MY, Kim Y, Lee SK, Chung JJ, Eo H, Yong HS, Hwang SS. Radiation Doses of Various CT Protocols: a Multicenter Longitudinal Observation Study. J Korean Med Sci 2016; 31 Suppl 1:S24-31. [PMID: 26908984 PMCID: PMC4756338 DOI: 10.3346/jkms.2016.31.s1.s24] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 11/23/2015] [Indexed: 11/25/2022] Open
Abstract
Emerging concerns regarding the hazard from medical radiation including CT examinations has been suggested. The purpose of this study was to observe the longitudinal changes of CT radiation doses of various CT protocols and to estimate the long-term efforts of supervising radiologists to reduce medical radiation. Radiation dose data from 11 representative CT protocols were collected from 12 hospitals. Attending radiologists had collected CT radiation dose data in two time points, 2007 and 2010. They collected the volume CT dose index (CTDIvol) of each phase, number of phases, dose length product (DLP) of each phase, and types of scanned CT machines. From the collected data, total DLP and effective dose (ED) were calculated. CTDIvol, total DLP, and ED of 2007 and 2010 were compared according to CT protocols, CT machine type, and hospital. During the three years, CTDIvol had significantly decreased, except for dynamic CT of the liver. Total DLP and ED were significantly decreased in all 11 protocols. The decrement was more evident in newer CT scanners. However, there was substantial variability of changes of ED during the three years according to hospitals. Although there was variability according to protocols, machines, and hospital, CT radiation doses were decreased during the 3 years. This study showed the effects of decreased CT radiation dose by efforts of radiologists and medical society.
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Affiliation(s)
- Jinhee Jang
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Seung Eun Jung
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Woo Kyoung Jeong
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Yeon Soo Lim
- Department of Radiology, Bucheon St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Bucheon, Korea
| | - Joon-Il Choi
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Michael Yong Park
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Yongsoo Kim
- Department of Radiology, Hanyang University Guri Hospital, College of Medicine, Hanyang University, Guri, Korea
| | - Seung-Koo Lee
- Department of Radiology, Severance Hospital, College of Medicine, Yonsei University, Seoul, Korea
| | - Jae-Joon Chung
- Department of Radiology, Gangnam Severance Hospital, College of Medicine, Yonsei University, Seoul, Korea
| | - Hong Eo
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Hwan Seok Yong
- Department of Radiology, Korea University Guro Hospital, College of Medicine, Korea University, Seoul, Korea
| | - Sung Su Hwang
- Department of Radiology, St. Vincent’s Hospital, College of Medicine, the Catholic University of Korea, Suwon, Korea
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44
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Pizzolato R, Romero JM. Neurosonology and noninvasive imaging of the carotid arteries. HANDBOOK OF CLINICAL NEUROLOGY 2016; 135:165-191. [PMID: 27432665 DOI: 10.1016/b978-0-444-53485-9.00009-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In this chapter, we review imaging of the extracranial carotid arteries and the indications for noninvasive carotid artery evaluation, measuring the degree of arterial stenosis and plaque morphology. We also analyze the types of noninvasive imaging, including carotid duplex ultrasound, transcranial Doppler, magnetic resonance angiography, and computer tomography angiography. We look at each of these modalities, briefly discussing techniques, benefits, limitations, and sources of error. Furthermore, we discuss the apparent accuracy and the need for multimodality imaging. Finally, an imaging algorithm for the evaluation of the extracranial carotid arteries is proposed, which is in routine use at our hospital.
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Affiliation(s)
- Raffaella Pizzolato
- Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Javier M Romero
- Department of Neuroradiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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45
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Chodick G, Levin M, Kleinerman RA, Shwarz M, Shalev V, Ashkenazi S, Horev G. Differences in characteristics of pediatric patients undergoing computed tomography between hospitals and primary care settings: implications for assessing cancer follow-up studies. Isr J Health Policy Res 2015; 4:33. [PMID: 26568819 PMCID: PMC4644629 DOI: 10.1186/s13584-015-0031-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 06/28/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Recently published analyses showed that computed tomography (CT) scans in pediatric patients are associated with increased risk of radiation-related cancer. These analyses were based on data collected both from either hospitals and primary care services. Study objectives were to characterize cohorts of pediatric patients in Israel undergoing CT scans in primary care compared to hospitals settings. These cohorts will be further used for evaluating cancer risks. METHODS The present study was conducted in Schneider Children Medical Center in Israel (SCMCI), the largest tertiary pediatric hospital in the country. Data were collected directly from the listings of the pediatric radiology department for the period 1985-2005. Results were compared with previously published data on pediatric CT in the primary healthcare service performed between 1999 and 2003 in a large health organization, Maccabi Healthcare Services (MHS). RESULTS During the study observation periods, 38,351 and 22,223 examinations were documented in 13,726 and 18,075 pediatric patients in SCMCI and MHS, respectively. Compared to pediatric patients in the primary care, patients undergoing CT scans in the hospital were more likely to be younger, to have multiple CT scans, and to be scanned in the trunk. Also, cancer-related indications accounted for nearly 50 % of all CT scans conducted in the hospital compared to only 3 % in primary care settings. CONCLUSIONS The results indicate major differences in the characteristics of children and adolescents scanned in hospitals compared to primary care settings. Some of these characteristics may be associated with cancer risk later in life, and should be taken into account in cancer risk assessments.
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Affiliation(s)
- Gabriel Chodick
- Medical Division, Maccabi Healthcare Services, Tel Aviv, Israel ; Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD USA ; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Levin
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruth A Kleinerman
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD USA
| | - Michael Shwarz
- Schneider Children's Medical Center in Israel, Petach-Tiqva, Israel
| | - Varda Shalev
- Medical Division, Maccabi Healthcare Services, Tel Aviv, Israel ; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shai Ashkenazi
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel ; Schneider Children's Medical Center in Israel, Petach-Tiqva, Israel
| | - Gad Horev
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel ; Schneider Children's Medical Center in Israel, Petach-Tiqva, Israel
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Computed Tomography Imaging in Patients with Congenital Heart Disease Part I: Rationale and Utility. An Expert Consensus Document of the Society of Cardiovascular Computed Tomography (SCCT). J Cardiovasc Comput Tomogr 2015; 9:475-92. [DOI: 10.1016/j.jcct.2015.07.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/17/2015] [Indexed: 12/16/2022]
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Spine Computed Tomography Radiation Dose Reduction: Protocol Refinement Based on Measurement Variation at Simulated Lower Radiation Acquisitions. Spine (Phila Pa 1976) 2015; 40:1613-9. [PMID: 26731706 DOI: 10.1097/brs.0000000000001097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective dose-simulation comparison. OBJECTIVE To determine if sufficient detail for preoperative analysis of bony anatomy can be acquired at substantially lower doses than those typically used. SUMMARY OF BACKGROUND DATA Computed tomography (CT) is a preoperative planning tool for spinal surgery. The pediatric population is at risk to express the harmful effects of ionizing radiation. Preoperative CT scans are presently performed at standard pediatric radiation doses not tailored for surgical planning. METHODS We used the validated GE Noise Injection software to retrospectively modify existing spine and chest CT scans from 10 patients to create CT images that simulated a standard dose (100%), 50% dose, and 25% dose scans. 4 orthopedic surgeons and a pediatric radiologist, blinded to dose, measured minimum medial-lateral pedicle width and maximum anterior-posterior bony length along the axis of presumed pedicle screw placement. A total of 90 axial images were generated to create our sample set. Measurements were evaluated for accuracy, precision, and consistency. RESULTS For any given rater, there was no clinically relevant difference between measurements at the different dose levels and no apparent degradation in precision at the different dose levels. Consistent variation was observed between raters, the likely result of individual differences in measurement approach. CONCLUSION Spinal CT scans done for preoperative planning can be performed at 25% of current radiation doses without a loss in surgical planning measurement accuracy or precision. These 25% dose-reduced scans would have average Computed Tomography Dose Index volume dose levels of roughly 1.0 to 2.5 mGy (depending on patient size) and size-specific dose estimates of roughly 2.5 mGy representing a substantial dose savings compared to current practice for many sites. Standardization of consistent landmarks may be useful to further improve inter-rater concordance.
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Mehta H, Acharya J, Mohan AL, Tobias ME, LeCompte L, Jeevan D. Minimizing Radiation Exposure in Evaluation of Pediatric Head Trauma: Use of Rapid MR Imaging. AJNR Am J Neuroradiol 2015; 37:11-8. [PMID: 26381555 DOI: 10.3174/ajnr.a4464] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/20/2015] [Indexed: 02/03/2023]
Abstract
BACKGROUND AND PURPOSE With >473,000 annual emergency department visits for children with traumatic brain injuries in the United States, the risk of ionizing radiation exposure during CT examinations is a real concern. The purpose of this study was to assess the validity of rapid MR imaging to replace CT in the follow-up imaging of patients with head trauma. MATERIALS AND METHODS A retrospective review of 103 pediatric patients who underwent initial head CT and subsequent follow-up rapid MR imaging between January 2010 and July 2013 was performed. Patients had minor head injuries (Glasgow Coma Scale, >13) that required imaging. Initial head CT was performed, with follow-up rapid MR imaging completed within 48 hours. A board-certified neuroradiologist, blinded to patient information and scan parameters, then independently interpreted the randomized cases. RESULTS There was almost perfect agreement in the ability to detect extra-axial hemorrhage on rapid MR imaging and CT (κ = 0.84, P < .001). Evaluation of hemorrhagic contusion/intraparenchymal hemorrhage demonstrated a moderate level of agreement between MR imaging and CT (κ = 0.61, P < .001). The ability of MR imaging to detect a skull fracture also showed a substantial level of agreement with CT (κ = 0.71, P < .001). Detection of diffuse axonal injury demonstrated a slight level of agreement between MR imaging and CT (κ = 0.154, P = .04). However, the overall predictive agreement for the detection of an axonal injury was 91%. CONCLUSIONS Rapid MR imaging is a valid technique for detecting traumatic cranial injuries and an adequate examination for follow-up imaging in lieu of repeat CT.
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Affiliation(s)
- H Mehta
- From the Departments of Radiology (H.M., J.A., L.L.)
| | - J Acharya
- From the Departments of Radiology (H.M., J.A., L.L.)
| | - A L Mohan
- Neurosurgery (A.L.M., M.E.T., D.J.), New York Medical College, Valhalla, New York
| | - M E Tobias
- Neurosurgery (A.L.M., M.E.T., D.J.), New York Medical College, Valhalla, New York
| | - L LeCompte
- From the Departments of Radiology (H.M., J.A., L.L.)
| | - D Jeevan
- Neurosurgery (A.L.M., M.E.T., D.J.), New York Medical College, Valhalla, New York
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Guo J, Zeitlin C, Wimmer-Schweingruber RF, Rafkin S, Hassler DM, Posner A, Heber B, Köhler J, Ehresmann B, Appel JK, Böhm E, Böttcher S, Burmeister S, Brinza DE, Lohf H, Martin C, Kahanpää H, Reitz G. MODELING THE VARIATIONS OF DOSE RATE MEASURED BY RAD DURING THE FIRSTMSLMARTIAN YEAR: 2012–2014. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/810/1/24] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Trauma centers, trauma management concepts, as well as integration of whole-body computed tomography (CT) reduced mortality significantly. The accuracy of a trauma care algorithm with emergency CT in children was evaluated. Data of 71 children with emergency CT were recorded retrospectively. In addition to epidemiological data admission date, kind of CT scan, mechanism of injury, missed diagnoses, injury severity score (ISS), admission to and time on intensive care unit (ICU), and time of hospitalization were observed. The algorithm for CT scanning was based on mechanism of injury, pattern of injury, and altered vital signs. Sixty-nine percent of the children reached the ER during on-call service hours. A percentage of 32.4 received a whole-body scan and 67.6 % a cranial scan. The mean ER ISS was 9.9 points (1-57). Children have different trauma mechanisms compared to adults. A percentage of 33.8 of the children had relevant trauma related findings in the CT scan. In 2 children, (2.8 %) 3 diagnoses (2.2 %) were initially missed. After reevaluation of the CT data, all diagnoses were identified. Thus, the accuracy of our algorithm in children was 100 %. In children, our algorithm detected all injuries, but only one third of the children had relevant trauma related findings in the CT scan. In order to reduce radiation exposure but preserve the advantages of CT, a new algorithm was developed with more flexibility taking the child's age and mental status more into account as well as clinical findings. The mechanism of injury itself is not anymore an indication for CT scanning.
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