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Demirci MG, Kesgin YM. Virtual Colonoscopy: Retrospective Comparison of the Findings in Supine and Prone Positions. Surg Innov 2025; 32:242-248. [PMID: 40033191 DOI: 10.1177/15533506251325349] [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] [Indexed: 03/05/2025]
Abstract
BackgroundEarly detection of colorectal cancer (CRC) is significantly associated with reduced morbidity and mortality. Virtual colonoscopy (VC) is a minimally invasive, safe and well-tolerated alternative procedure to traditional colonoscopy. Therefore, we aimed to evaluate the findings of VC particularly in supine and prone positions as well as to contribute to the practical challenges of procedure.MethodsTotal number of 20 patients who underwent VC were included in this retrospective study. After proper bowel cleansing was achieved, intestinal dilatation was performed by injecting air into the rectum. Two different shots were performed in the supine and prone positions. Additionally, intestinal diameters were measured from the cecum to the rectum at their widest point via 2-dimensional coronal reformat.ResultsPolyps were detected in 3 patients which were confirmed by optical colonoscopy. The mean cecum diameter was detected as the largest diameter in the supine and prone examinations. In both supine and prone examinations, the distal descending colon was the most challenging site. Additionally, the mean descending colon diameter calculated in the prone position (40.9 ± 6.4 mm) was found to be statistically larger than descending colon diameter calculated in the supine position (36.1 ± 5.3 mm) (P = 0.001).ConclusionsOur findings clearly demonstrated that combination of prone and supine scanning provides clear field of vision on narrow parts of the colon which improves accurate estimation for polyp detection. Furthermore, VC appears to be more comfortable, safe, fast, and cost-efffective procedure for CRC screening with advantages of low radiation exposure, extracolonic findings and lack of sedation requirements.
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Affiliation(s)
| | - Yasir Musa Kesgin
- Department of General Surgery, Bakirkoy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkiye
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Lovett JT, Huang C, Prabhu V. Diagnostic performance and clinical outcomes of computed tomography colonography in a sick inpatient population. Clin Imaging 2025; 119:110401. [PMID: 39862650 DOI: 10.1016/j.clinimag.2025.110401] [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: 10/11/2024] [Revised: 12/18/2024] [Accepted: 01/02/2025] [Indexed: 01/27/2025]
Abstract
PURPOSE Though prior studies have proven CTC's efficacy in outpatients, its utility in the inpatient setting has not been studied. We evaluated the efficacy of a modified CTC protocol in the inpatient setting, primarily for patients awaiting organ transplantation. METHODS This retrospective study compared a group of inpatient CTCs from 2019 to 2021 and a randomly selected, age-matched 2:1 control group of outpatient CTCs. Both groups were assessed based on established criteria from literature. RESULTS 10 % (63/652) of CTCs were performed in the inpatient setting, of which 29 were excluded, yielding 34 inpatient cases. 90 % (589/652) of CTCs were performed in the outpatient setting, from which 68 randomly selected, age-matched patients were selected as controls. Significantly more (24 %, 8/34) inpatients expired due to extracolonic causes (vs. 1 %, 1/68 outpatients, p < 0.05). 62 % (21/34) of inpatient CTCs were reported as diagnostic (vs. 74 %, 50/68 outpatient, p = 0.22). Significantly more inpatients (12 %, 4/34) than outpatients (1 %, 1/68) were unable to tolerate two imaging positions (p = 0.02). Subsequent colonoscopy was performed in 24 % (8/34) of inpatients, revealing pathologies including colonic polyps and non-bleeding ulcers. Inpatient CTCs had lower average quality scores, significant for one reviewer (p = 0.009-0.054). Inpatients had a larger number of segments with: >25 % residual fluid (1.22-1.28 inpatients vs. 0.60-0.73 outpatients, p = 0.003-0.026) and inadequate fluid tagging (1.10 inpatients vs. 0.49 outpatients, p = 0.046-0.0501). Distention was not significantly different between groups (p = 0.317-0.410). CONCLUSION Quality of inpatient CTC was inferior to outpatient CTCs across several metrics. 24 % undergoing inpatient CTC died of extracolonic causes within 22 months, and most did not have findings warranting intervention, questioning the value of this difficult exam in this patient population. Routine CT may be sufficient to exclude large or metastatic colonic lesions precluding transplant.
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Affiliation(s)
- Jessica T Lovett
- NYU Langone Health, Department of Internal Medicine, 660 1st Ave, New York, NY 10016, United States.
| | - Chenchan Huang
- NYU Langone Health, Department of Radiology, 660 1st Ave, New York, NY 10016, United States
| | - Vinay Prabhu
- NYU Langone Health, Department of Radiology, 660 1st Ave, New York, NY 10016, United States
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Mang T, Lampichler K, Scharitzer M. [CT colonography : Technique and indications]. RADIOLOGIE (HEIDELBERG, GERMANY) 2023; 63:418-428. [PMID: 37249607 PMCID: PMC10234944 DOI: 10.1007/s00117-023-01153-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/18/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Dedicated radiological expertise and a high-quality examination, performed according to current technical standards and for accepted indications, are prerequisite to achieve excellent results with CT colonography (CTC). OBJECTIVES The aim of this article is to review current standards of the examination technique as well as indications and contraindications for CTC based on recent recommendations and guidelines. MATERIALS AND METHODS Based on extensive literature research, current knowledge about the examination technique and the indications and contraindications is summarized. RESULTS CTC is the radiological examination of choice for the detection of colorectal neoplasia. Beside incomplete or refused colonoscopy and contraindications to colonoscopy, CTC is also a noninvasive option for opportunistic colorectal cancer screening. The examination technique is based on a CTC-specific patient preparation scheme that includes fecal tagging, colonic distension, low-dose CT scans in two patient positions and a combined 2D and 3D data evaluation. CONCLUSIONS Performing CTC according to current technical standards is prerequisite for high-quality examinations and is, thus, also a key factor to obtain a correct diagnosis. CTC is a noninvasive examination, capable of providing clinically relevant diagnoses for a wide range of indications.
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Affiliation(s)
- Thomas Mang
- Universitätsklinik für Radiologie und Nuklearmedizin, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich.
| | - Katharina Lampichler
- Universitätsklinik für Radiologie und Nuklearmedizin, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
| | - Martina Scharitzer
- Universitätsklinik für Radiologie und Nuklearmedizin, Medizinische Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich
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Computed tomographic colonography versus double-contrast barium enema for the preoperative evaluation of rectal cancer. Surg Today 2021; 52:755-762. [PMID: 34816321 DOI: 10.1007/s00595-021-02411-5] [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: 05/06/2021] [Accepted: 08/09/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE We investigated whether or not computed tomographic colonography (CTC) is a viable alternative to double-contrast barium enema (BE) for a preoperative rectal cancer evaluation. METHODS The size and distance from the anal canal to the lower or upper tumor borders were laterally measured in 147 patients who underwent CTC and BE. Measurements were grouped into early cancer, advanced, and after chemoradiation therapy (CRT). RESULTS In the early and advanced cancer groups, all lesions were visualized by BE. In contrast, 3 (7.8%) early and 8 (7.3%) advanced cases, located at the anterior wall near the anal canal, were not visualized by CTC because of liquid level formation. In the CRT group, 16 (23.5%) and 4 (5.8%) cases were not visualized by CTC and BE, respectively. The BE and CTC size measurements were similar among cohorts. However, the distance from the anal canal's superior margin tended to be longer with BE, especially in early cancer. The differences in distance from the anal canal were significantly larger in the early cancer group than in the other two groups (p = 0.0024). CONCLUSION CTC may be a viable alternative imaging modality in some cases. However, BE should be employed in anterior wall cases near the anal canal and CRT cases.
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Liu JJ, Xue HD, Liu W, Yan J, Pan WD, Li B, Xu K, Wang Y, Li P, Xiao Y, Jin ZY. CT colonography with spectral filtration and advanced modeled iterative reconstruction in the third-generation dual-source CT: image quality, radiation dose and performance in clinical utility. Acad Radiol 2021; 28:e127-e136. [PMID: 32434689 DOI: 10.1016/j.acra.2020.03.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 12/23/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate image quality, radiation dose and its diagnostic performance in clinical utility of CT colonography (CTC) applying spectral filtration and advanced modeled iterative reconstruction (ADMIRE) techniques in third-generation dual-source CT. MATERIALS AND METHODS A total of 125 patients for screening or diagnostic purposes underwent CTC at 120kVp standard dose (120kVp-STD) with filtered-back projection reconstruction (FBP) in supine position, then at a tin-filtered 150 kVp low dose (Sn150kVp-LD) and a tin-filtered 100 kVp ultra-low dose (Sn100kVp-ULD) with ADMIRE reconstruction in prone position. Radiation metrics were recorded. Objective and subjective image qualities were compared, and the diagnostic performance was assessed for both colonic and extracolonic findings using CTC reporting and data system (C-RADS). RESULTS The effective dose was significantly lower for Sn150kVp-LD and Sn100kVp-ULD than 120kVp-STD protocol, resulting in 22.5% and 87.5% reductions (1.55±0.30 and 0.25±0.07 mSv vs. 2.00±0.52 mSv; both p<0.01), respectively. Image noise and signal-to-noise ratio were improved significantly for Sn150kVp-LD with ADMIRE compared with 120kVp-STD, both of which had similar excellent 2D and 3D subjective image quality with equivalent diagnostic performance. Sn100kVp-ULD with ADMIRE had decreased subjective image quality and significant different C-RADS extracolonic-score (E-score) compared with 120kVp-STD, however, C-RADS colonic-score (C-score) of that showed no significantly difference. CONCLUSION Sn150kVp and Sn100kVp with ADMIRE reconstruction provide an alternative low dose CTC strategy and could be feasible in clinical screening or diagnostic scenarios.
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Affiliation(s)
- Jing-Juan Liu
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Hua-Dan Xue
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Wei Liu
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China.
| | - Jing Yan
- Siemens Medical System, 201318, Shanghai, China
| | - Wei-Dong Pan
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Bin Li
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Kai Xu
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Yun Wang
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Ping Li
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Yi Xiao
- Department of General Surgery, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
| | - Zheng-Yu Jin
- Department of Radiology, Peking Union Medical College Hospital, Shuaifuyuan No. 1, Dongcheng District, 100730, Beijing, China
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Popic J, Tipuric S, Balen I, Mrzljak A. Computed tomography colonography and radiation risk: How low can we go? World J Gastrointest Endosc 2021; 13:72-81. [PMID: 33763187 PMCID: PMC7958467 DOI: 10.4253/wjge.v13.i3.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/23/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Computed tomography colonography (CTC) has become a key examination in detecting colonic polyps and colorectal carcinoma (CRC). It is particularly useful after incomplete optical colonoscopy (OC) for patients with sedation risks and patients anxious about the risks or potential discomfort associated with OC. CTC's main advantages compared with OC are its non-invasive nature, better patient compliance, and the ability to assess the extracolonic disease. Despite these advantages, ionizing radiation remains the most significant burden of CTC. This opinion review comprehensively addresses the radiation risk of CTC, incorporating imaging technology refinements such as automatic tube current modulation, filtered back projections, lowering the tube voltage, and iterative reconstructions as tools for optimizing low and ultra-low dose protocols of CTC. Future perspectives arise from integrating artificial intelligence in computed tomography machines for the screening of CRC.
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Affiliation(s)
- Jelena Popic
- Department of Radiology, University Hospital Merkur, School of Medicine, University of Zagreb, Zagreb 10000, Croatia
| | - Sandra Tipuric
- Department of Family Medicine, Health Center Zagreb-East, Zagreb 10000, Croatia
| | - Ivan Balen
- Department of Gastroenterology and Endocrinology, General Hospital Slavonski brod “Dr. Josip Bencevic”, Slavonski Brod 35000, Croatia
| | - Anna Mrzljak
- Department of Medicine, Merkur University Hospital, School of Medicine, University of Zagreb, Zagreb 10000, Croatia
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Ricci ZJ, Kobi M, Flusberg M, Yee J. CT Colonography in Review With Tips and Tricks to Improve Performance. Semin Roentgenol 2020; 56:140-151. [PMID: 33858640 DOI: 10.1053/j.ro.2020.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zina J Ricci
- Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY.
| | - Mariya Kobi
- Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY
| | - Milana Flusberg
- Westchester Medical Center/New York Medical College, Valhalla, NY
| | - Judy Yee
- Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY
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Hsieh YH, Leung FW. Increase your adenoma detection rate without using fancy adjunct tools. Tzu Chi Med J 2018; 30:127-134. [PMID: 30069119 PMCID: PMC6047331 DOI: 10.4103/tcmj.tcmj_86_18] [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] [Received: 01/09/2018] [Revised: 02/24/2018] [Accepted: 03/28/2018] [Indexed: 02/07/2023] Open
Abstract
The correlation between a low adenoma detection rate (ADR) and interval cancers (ICs) has made ADR one of the most important quality indicators for colonoscopy. Data from nation-wide colorectal cancer (CRC) screening programs showed that there is room for improvement in ADR in order to reduce ICs in Taiwan. Measures with and without adjunct tools have been shown to have the potential to increase ADR, with the latter being more convenient to apply without additional cost. Optimal withdrawal techniques coupled with sufficient withdrawal time, training endoscopists with emphasis on recognition of subtle characteristics of flat lesions, dynamic position changes during the withdrawal phase, removing small polyps found during insertion, and retroflexion in the right colon have all been associated with increased ADR. In particular, water exchange (WE), which is characterized using water in lieu of air and suction removal of infused water during insertion, appears to meet the needs of colonoscopy patients in Taiwan. Analyses of both primary and secondary outcome variables of recently published studies have consistently shown that WE yields higher ADR than traditional air insufflation, even in propofol-sedated patients. Colonoscopists participating in the nationwide CRC screening program in Taiwan should consider applying one or more of the above measures to improve ADR and hopefully reduce ICs.
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Affiliation(s)
- Yu-Hsi Hsieh
- Division of Gastroenterology, Department of Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Felix W. Leung
- Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hill, CA, USA
- Division of Gastroenterology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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9
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Fuster D, Pagès M, Granados U, Perlaza P, Rubello D, Lomeña F. Update on PET/CT colonography in the diagnosis of colorectal cancer. Rev Esp Med Nucl Imagen Mol 2016; 35:246-52. [DOI: 10.1016/j.remn.2016.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/02/2016] [Accepted: 05/03/2016] [Indexed: 12/23/2022]
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10
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Fuster D, Pagès M, Granados U, Perlaza P, Rubello D, Lomeña F. Update on PET/CT colonography in the diagnosis of colorectal cancer. Rev Esp Med Nucl Imagen Mol 2016. [DOI: 10.1016/j.remnie.2016.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Maggialetti N, Capasso R, Pinto D, Carbone M, Laporta A, Schipani S, Piccolo CL, Zappia M, Reginelli A, D'Innocenzo M, Brunese L. Diagnostic value of computed tomography colonography (CTC) after incomplete optical colonoscopy. Int J Surg 2016; 33 Suppl 1:S36-44. [PMID: 27255132 DOI: 10.1016/j.ijsu.2016.05.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION This study evaluated the role of computed tomography colonography (CTC) in patients who previously underwent incomplete optical colonoscopy (OC). We analyzed the impact of colonic lesions in intestinal segments not studied by OC and extracolonic findings in these patients. METHODS Between January 2014 and May 2015, 61 patients with a history of abdominal pain and incomplete OC examination were studied by CTC. CTCs were performed by 320-row CT scan in both the supine and the prone position, without intravenous administration of contrast medium. In all patients both colonic findings and extracolonic findings were evaluated. RESULTS Among the study group, 24 CTC examinations were negative for both colonic and extracolonic findings while 6 examinations revealed the presence of both colonic and extracolonic findings. In 24 patients CTC depicted colonic anomalies without extracolonic ones, while in 7 patients it showed extracolonic findings without colonic ones. DISCUSSION CTC is a noninvasive imaging technique with the advantages of high diagnostic performance, rapid data acquisition, minimal patient discomfort, lack of need for sedation, and virtually no recovery time. CTC accurately allows the evaluation of the nonvisualized part of the colon after incomplete OC and has the distinct advantage to detect clinically important extracolonic findings in patients with incomplete OC potentially explaining the patient's symptoms and conditioning their therapeutic management. CONCLUSION CTC accurately allows the assessment of both colonic and extracolonic pathologies representing a useful diagnostic tool in patients for whom complete OC is not achievable.
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Affiliation(s)
- N Maggialetti
- Department of Medicine and Health Science, University of Molise, Campobasso, Italy.
| | - R Capasso
- Department of Internal and Experimental Medicine, Magrassi-Lanzara, Second University of Naples, Piazza Miraglia 2, 80138 Naples, Italy.
| | - D Pinto
- Radiological Research, Molfetta, BA, Italy.
| | - M Carbone
- Department of Radiology, A.O.U. San Giovanni di Dio e Ruggi d'Aragona, Salerno, Italy.
| | - A Laporta
- Department of Radiology, A.O. Solofra, Italy.
| | - S Schipani
- Department of Medicine and Health Science, University of Molise, Campobasso, Italy.
| | - C L Piccolo
- Department of Medicine and Health Science, University of Molise, Campobasso, Italy.
| | - M Zappia
- Department of Medicine and Health Science, University of Molise, Campobasso, Italy.
| | - A Reginelli
- Department of Internal and Experimental Medicine, Magrassi-Lanzara, Second University of Naples, Piazza Miraglia 2, 80138 Naples, Italy.
| | | | - L Brunese
- Department of Medicine and Health Science, University of Molise, Campobasso, Italy.
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Scalise P, Mantarro A, Pancrazi F, Neri E. Computed tomography colonography for the practicing radiologist: A review of current recommendations on methodology and clinical indications. World J Radiol 2016; 8:472-483. [PMID: 27247713 PMCID: PMC4882404 DOI: 10.4329/wjr.v8.i5.472] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/23/2015] [Accepted: 02/24/2016] [Indexed: 02/06/2023] Open
Abstract
Colorectal cancer (CRC) represents one of the most relevant causes of morbidity and mortality in Western societies. CRC screening is actually based on faecal occult blood testing, and optical colonoscopy still remains the gold standard screening test for cancer detection. However, computed tomography colonography (CT colonography) constitutes a reliable, minimally-invasive method to rapidly and effectively evaluate the entire colon for clinically relevant lesions. Furthermore, even if the benefits of its employment in CRC mass screening have not fully established yet, CT colonography may represent a reasonable alternative screening test in patients who cannot undergo or refuse colonoscopy. Therefore, the purpose of our review is to illustrate the most updated recommendations on methodology and the current clinical indications of CT colonography, according to the data of the existing relevant literature.
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Jang JK, Park SH, Lee JS, Kim HJ, Kim AY, Ha HK. Effect of Reducing Abdominal Compression during Prone CT Colonography on Ascending Colonic Rotation during Supine-to-Prone Positional Change. Korean J Radiol 2016; 17:47-55. [PMID: 26798215 PMCID: PMC4720810 DOI: 10.3348/kjr.2016.17.1.47] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/06/2015] [Indexed: 01/27/2023] Open
Abstract
Objective To determine the effect of reduced abdominal compression in prone position on ascending colonic movement during supine-to-prone positional change during CT colonography (CTC). Materials and Methods Eighteen consecutive patients who had undergone prone CTC scanning with cushion blocks placed under the chest and hip/thigh to reduce abdominal compression and had confirmed sessile polyps ≥ 6 mm in the well-distended, straight, mid-ascending colon, were included. Radial location along the ascending colonic luminal circumference (°) was measured for 24 polyps and 54 colonic teniae on supine and prone CTC images. The supine-to-prone change ranging between -180° and +180° (- and + for internal and external colonic rotations, respectively), was determined. In addition, possible causes of any ascending colonic rotations were explored. Results Abdominal compression during prone CTC scanning completely disappeared with the use of cushion blocks in 17 of 18 patients. However, some degrees of ascending colonic rotation were still observed, with the radial location changes of -22° to 61° (median, 13.9°) for the polyps and similar degrees for teniae. Fifty-four percent and 56% of polyps and teniae, respectively, showed changes > 10°. The radial location change of the polyps was significantly associated with the degree of anterior shift of the small bowel and mesentery (r = 0.722, p < 0.001) and the degree of posterior displacement of the ascending colon (r = 0.566, p = 0.004) during supine-to-prone positional change. Conclusion Ascending colonic rotation upon supine-to-prone positional change during CTC, mostly in the form of external rotation, is not eliminated by removing abdominal compression in prone position.
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Affiliation(s)
- Jong Keon Jang
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Seong Ho Park
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Jong Seok Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Hyun Jin Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Ah Young Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Hyun Kwon Ha
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
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14
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Lee SW, Chang JH, Ji JS, Maeong IH, Cheung DY, Kim JS, Cho YS, Chung WJ, Lee BI, Kim SW, Kim BW, Choi H, Choi MG. Effect of Dynamic Position Changes on Adenoma Detection During Colonoscope Withdrawal: A Randomized Controlled Multicenter Trial. Am J Gastroenterol 2016; 111:63-69. [PMID: 26526085 DOI: 10.1038/ajg.2015.354] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 09/01/2015] [Accepted: 09/02/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Adequate luminal distension is essential for improving adenoma detection during colonoscope withdrawal. A few crossover studies have reported that dynamic position changes maximize luminal distension and increase adenoma detection rates (ADR). We designed a multicenter, randomized, parallel-group trial to verify the effect of dynamic position changes on colonic adenoma detection. METHODS This study was conducted at the six hospitals of the Catholic University of Korea. Patients aged 45-80 years who underwent a colonoscopy for the first time were included. In the position change group, the position changes during colonoscope withdrawal were as follows: cecum, ascending colon, and hepatic flexure: left lateral position; transverse colon: supine position; splenic flexure, descending colon, sigmoid colon, and rectum: right lateral position. In the control group, the examinations were performed entirely in the left lateral position during colonoscope withdrawal. The primary outcome measure was the ADR, which was defined as the proportion of patients with ≥1 adenoma. RESULTS A total of 1,072 patients were randomized into the position change group (536 patients) or the control group (536 patients). The ADR was higher in the position change group than in the control group (42.4 vs. 33.0%, P=0.002). More adenomas were detected per subject in the position change group (0.90 vs. 0.67, P=0.01). Increases in the number of adenomas were observed in examinations of the transverse colon (0.22 vs. 0.13, P=0.016) and the left colon (0.37 vs. 0.27, P=0.045). A significant increase in the ADR was observed for endoscopists with a relatively low detection rate. For endoscopists with a high detection rate, non-significant changes in the ADR were observed. CONCLUSIONS Dynamic position changes during colonoscope withdrawal increased the ADR.
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Affiliation(s)
- Seung-Woo Lee
- Department of Internal Medicine, Daejeon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Jae Hyuck Chang
- Department of Internal Medicine, Bucheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Republic of Korea
| | - Jeong-Seon Ji
- Division of Gastroenterology, Department of Internal Medicine, Incheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Incheon, Republic of Korea
| | - Il Ho Maeong
- Department of Internal Medicine, Bucheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Republic of Korea
| | - Dae Young Cheung
- Department of Internal Medicine, Yeouido St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon Sung Kim
- Division of Gastroenterology, Department of Internal Medicine, Incheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Incheon, Republic of Korea
| | - Young-Seok Cho
- Department of Internal Medicine, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Wook-Jin Chung
- Department of Internal Medicine, Gachon University Gil Medical Center, College of Medicine, Gachon University, Incheon, Republic of Korea
| | - Bo-In Lee
- Department of Internal Medicine, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Woo Kim
- Departments of Internal Medicine, Uijeongbu St Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea
| | - Byung-Wook Kim
- Division of Gastroenterology, Department of Internal Medicine, Incheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Incheon, Republic of Korea
| | - Hwang Choi
- Division of Gastroenterology, Department of Internal Medicine, Incheon St Mary's Hospital, College of Medicine, The Catholic University of Korea, Incheon, Republic of Korea
| | - Myung-Gyu Choi
- Department of Internal Medicine, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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15
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Schmidt SA, Ernst AS, Beer M, Juchems MS. 3D detection of colonic polyps by CT colonography: accuracy, pitfalls, and solutions by adjunct 2D workup. Clin Radiol 2015. [PMID: 26220124 DOI: 10.1016/j.crad.2015.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Computed tomography colonography (CTC) enables evaluation of the colon with minimal invasiveness. In spite of advances in multidetector CT (MDCT) technology and advanced software features, including electronic bowel cleansing (digital removal and tagging of fluid and debris), a number of potential pitfalls in the evaluation of the 3D volumetric dataset persist. The purpose of this article is to illustrate the strengths and potential pitfalls in the detection of colorectal polyps using CTC via a primary three-dimensional (3D) approach for evaluation.
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Affiliation(s)
- S A Schmidt
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany.
| | - A S Ernst
- Department of Radiology, Donauklinik Neu-Ulm, Krankenhausstrasse 11, D-89231 Neu-Ulm, Germany
| | - M Beer
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - M S Juchems
- Department of Diagnostic and Interventional Radiology, Konstanz Hospital, Luisenstrasse 7, D-87464 Konstanz, Germany
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Volumetric analysis of colonic distention according to patient position at CT colonography: diagnostic value of the right lateral decubitus series. AJR Am J Roentgenol 2015; 203:W623-8. [PMID: 25415727 DOI: 10.2214/ajr.13.12369] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The purpose of this study was to compare total colonic gas volume and segmental luminal distention according to patient position on CT colonography (CTC), as well as to determine which two views should constitute the routine protocol. MATERIALS AND METHODS Volumetric analysis was retrospectively performed on CTC examinations from 146 adults (mean age, 59.2 years; 81 men and 65 women; mean body mass index [BMI], 30.9) for whom supine, prone, and right lateral decubitus series were sequentially obtained using continuous low-pressure CO2 insufflation. Total colonic gas volumes were assessed using a novel automated volumetric tool. In addition, two radiologists scored distention by segment using a 4-point scale (4=optimal; 3=adequate; 2=inadequate; 1=collapsed). RESULTS Mean (±SD) colonic gas volumes for supine, prone, and decubitus positioning were 1617±567, 1441±505, and 1901±627, respectively (p<0.001). Colonic volume was highest on the right lateral decubitus series in 73.3% (107/146) and lowest in 6.2% (9/146) of cases, whereas the prone series was highest in 0.7% (1/146) and lowest in 73.3% (107/146) of cases. Overall mean segmental reader scores and percentages of inadequate or collapsed for supine, prone, and decubitus positions were 3.48, 3.33, and 3.71 and 10.4%, 12.1%, and 4.2%, respectively (p<0.001). The only mean segmental scores below 3.0 were the sigmoid colon on supine (2.68) and prone (2.58) series, compared with 3.23 on decubitus series (p<0.001). Improvement in distention in both decubitus and supine positions over the prone position increased further with increasing BMI (p<0.001). CONCLUSION The right lateral decubitus position consistently yields the best colonic distention at CTC and significantly improves evaluation of the sigmoid colon. Prone distention was the worst, particularly as BMI increased. Routine supine and decubitus positioning should be considered for standard CTC protocols, particularly in obese individuals. Automated volumetric analysis provides for rapid objective assessment of colonic distention.
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Levine MS, Yee J. History, evolution, and current status of radiologic imaging tests for colorectal cancer screening. Radiology 2015; 273:S160-80. [PMID: 25340435 DOI: 10.1148/radiol.14140531] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Colorectal cancer screening is thought to be an effective tool with which to reduce the mortality from colorectal cancer through early detection and removal of colonic adenomas and early colon cancers. In this article, we review the history, evolution, and current status of imaging tests of the colon-including single-contrast barium enema, double-contrast barium enema, computed tomographic (CT) colonography, and magnetic resonance (MR) colonography-for colorectal cancer screening. Despite its documented value in the detection of colonic polyps, the double-contrast barium enema has largely disappeared as a screening test because it is widely perceived as a labor-intensive, time-consuming, and technically demanding procedure. In the past decade, the barium enema has been supplanted by CT colonography as the major imaging test in colorectal cancer screening in the United States, with MR colonography emerging as another viable option in Europe. Although MR colonography does not require ionizing radiation, the radiation dose for CT colonography has decreased substantially, and regular screening with this technique has a high benefit-to-risk ratio. In recent years, CT colonography has been validated as an effective tool for use in colorectal cancer screening that is increasingly being disseminated.
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Affiliation(s)
- Marc S Levine
- From the Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104 (M.S.L.); and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco Veterans Affairs Medical Center, San Francisco, Calif (J.Y.)
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Sakamoto T, Utsunomiya D, Mitsuzaki K, Matsuda K, Kawakami M, Yamamura S, Urata J, Arakawa A, Yamashita Y. Colonic distention at screening CT colonography: role of spasmolytic agents and body habitus. Kurume Med J 2014; 61:9-15. [PMID: 25400236 DOI: 10.2739/kurumemedj.ms64002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Sufficient colonic dilation is important when using CT colonography (CTC) for colorectal cancer screening. We investigated the effect of antispasmodic agents and the patient body habitus on the degree of colonic dilation in screening CTC.We assessed the effect of clinical characteristics [age, gender, body mass index (BMI), and the presence of diverticula] and the use of antispasmodics on colonic distention in 140 patients who underwent CTC for colorectal cancer screening. The CTC was performed in both the supine- and prone positions. Seventy patients received antispasmodics prior to CT examination and the other 70 did not. Colonic distention was scored using a 5-point scale: 1=collapsed, 2=poorly visualized, 3=visualized but underdistended, 4=acceptable, and 5=excellent. Images scored as 4 or 5 were considered to be of diagnostic quality. The mean visual evaluation score was significantly higher in the supine- than the prone position (4.2±0.5 vs. 4.0±0.5, p<0.01). For the supine position, only the use of antispasmodic was statistically associated with sufficient colonic dilation by univariate logistic analysis (odds ratio=2.365, p=0.03). For the prone position, age, BMI, and the use of antispasmodic were statistically associated with sufficient colonic dilation by multivariate analysis. The odds ratio of these parameters was 0.955 (p=0.02), 0.874 (p=0.03), and 2.391 (p=0.02), respectively.We obtained sufficient colonic dilation with an antispasmodic for CTC in both positions. Younger age and a lower BMI were also associated with better colonic dilation in the prone position.
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19
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Sequential Monte Carlo tracking of the marginal artery by multiple cue fusion and random forest regression. Med Image Anal 2014; 19:164-75. [PMID: 25461335 DOI: 10.1016/j.media.2014.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 09/12/2014] [Accepted: 09/23/2014] [Indexed: 01/02/2023]
Abstract
Given the potential importance of marginal artery localization in automated registration in computed tomography colonography (CTC), we have devised a semi-automated method of marginal vessel detection employing sequential Monte Carlo tracking (also known as particle filtering tracking) by multiple cue fusion based on intensity, vesselness, organ detection, and minimum spanning tree information for poorly enhanced vessel segments. We then employed a random forest algorithm for intelligent cue fusion and decision making which achieved high sensitivity and robustness. After applying a vessel pruning procedure to the tracking results, we achieved statistically significantly improved precision compared to a baseline Hessian detection method (2.7% versus 75.2%, p<0.001). This method also showed statistically significantly improved recall rate compared to a 2-cue baseline method using fewer vessel cues (30.7% versus 67.7%, p<0.001). These results demonstrate that marginal artery localization on CTC is feasible by combining a discriminative classifier (i.e., random forest) with a sequential Monte Carlo tracking mechanism. In so doing, we present the effective application of an anatomical probability map to vessel pruning as well as a supplementary spatial coordinate system for colonic segmentation and registration when this task has been confounded by colon lumen collapse.
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20
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Ou G, Kim E, Lakzadeh P, Tong J, Enns R, Ramji A, Whittaker S, Ko HH, Bressler B, Halparin L, Lam E, Amar J, Telford J. A randomized controlled trial assessing the effect of prescribed patient position changes during colonoscope withdrawal on adenoma detection. Gastrointest Endosc 2014; 80:277-83. [PMID: 24629419 DOI: 10.1016/j.gie.2014.01.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/17/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND High-quality colonoscope withdrawal technique is associated with a higher adenoma detection rate. Position change is routinely used in barium enema and CT colonography to facilitate adequate distension of the colon and promote movement of fluid from the segment of the colon being assessed. OBJECTIVE To determine whether prescribed position changes during colonoscope withdrawal affect the adenoma detection rate compared with the usual care per endoscopist. DESIGN Prospective, randomized, controlled trial. SETTING Tertiary-care, university-affiliated hospital. PATIENTS Patients referred for outpatient colonoscopy between July 2011 and July 2012 were evaluated for eligibility. Inclusion criteria were outpatient status and age ≥40 years. Exclusion criteria were (1) complete colonoscopy within 1 year before the procedure, (2) inability to provide informed consent, (3) incomplete colonoscopy to the cecum, (4) previous bowel resection, (5) inflammatory bowel disease, (6) colonic polyposis syndrome, (7) inadequate bowel preparation, and (8) musculoskeletal disorder or other mobility issues limiting effective patient position changes during colonoscopy. INTERVENTIONS Prescribed position changes during colonoscope withdrawal. MAIN OUTCOME MEASUREMENTS Polyp detection rate (PDR) and adenoma detection rate (ADR). RESULTS A total of 776 patients were enrolled, with 388 in the dynamic group. There was no difference in PDR (odds ratio [OR] 0.99; P = .93) or ADR (OR 1.17; P = .28). Colonoscope withdrawal time was longer in the dynamic group (median time 466.5 vs 422.5 seconds; P < .0001). LIMITATIONS Single-center study. Indication for procedure not controlled. Lack of standardized bowel preparation and blinding. CONCLUSION Prescribed position changes during colonoscope withdrawal do not affect polyp/adenoma detection compared with the usual practice when the baseline ADR is above the recommended standard. ( CLINICAL TRIAL REGISTRATION NUMBER NCT01395173.).
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Affiliation(s)
- George Ou
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Edward Kim
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pardis Lakzadeh
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jessica Tong
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert Enns
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alnoor Ramji
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott Whittaker
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hin Hin Ko
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian Bressler
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lawrence Halparin
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eric Lam
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jack Amar
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jennifer Telford
- Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
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21
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Boone DJ, Halligan S, Roth HR, Hampshire TE, Helbren E, Slabaugh GG, McQuillan J, McClelland JR, Hu M, Punwani S, Taylor SA, Hawkes DJ. CT colonography: external clinical validation of an algorithm for computer-assisted prone and supine registration. Radiology 2013; 268:752-60. [PMID: 23687175 DOI: 10.1148/radiol.13122083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE To perform external validation of a computer-assisted registration algorithm for prone and supine computed tomographic (CT) colonography and to compare the results with those of an existing centerline method. MATERIALS AND METHODS All contributing centers had institutional review board approval; participants provided informed consent. A validation sample of CT colonographic examinations of 51 patients with 68 polyps (6-55 mm) was selected from a publicly available, HIPAA compliant, anonymized archive. No patients were excluded because of poor preparation or inadequate distension. Corresponding prone and supine polyp coordinates were recorded, and endoluminal surfaces were registered automatically by using a computer algorithm. Two observers independently scored three-dimensional endoluminal polyp registration success. Results were compared with those obtained by using the normalized distance along the colonic centerline (NDACC) method. Pairwise Wilcoxon signed rank tests were used to compare gross registration error and McNemar tests were used to compare polyp conspicuity. RESULTS Registration was possible in all 51 patients, and 136 paired polyp coordinates were generated (68 polyps) to test the algorithm. Overall mean three-dimensional polyp registration error (mean ± standard deviation, 19.9 mm ± 20.4) was significantly less than that for the NDACC method (mean, 27.4 mm ± 15.1; P = .001). Accuracy was unaffected by colonic segment (P = .76) or luminal collapse (P = .066). During endoluminal review by two observers (272 matching tasks, 68 polyps, prone to supine and supine to prone coordinates), 223 (82%) polyp matches were visible (120° field of view) compared with just 129 (47%) when the NDACC method was used (P < .001). By using multiplanar visualization, 48 (70%) polyps were visible after scrolling ± 15 mm in any multiplanar axis compared with 16 (24%) for NDACC (P < .001). CONCLUSION Computer-assisted registration is more accurate than the NDACC method for mapping the endoluminal surface and matching the location of polyps in corresponding prone and supine CT colonographic acquisitions.
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Affiliation(s)
- Darren J Boone
- Centre for Medical Imaging and Centre for Medical Image Computing, University College London, Podium Level 2, University College Hospital, 235 Euston Rd, London NW1 2BU, England
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Ganeshan D, Elsayes KM, Vining D. Virtual colonoscopy: Utility, impact and overview. World J Radiol 2013; 5:61-67. [PMID: 23671742 PMCID: PMC3650206 DOI: 10.4329/wjr.v5.i3.61] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 09/13/2012] [Accepted: 01/31/2013] [Indexed: 02/06/2023] Open
Abstract
Computed tomography (CT) colonoscopy is a well-established technique for evaluation of colorectal cancer. Significant advances have been made in the technique of CT colonoscopy since its inception. Excellent results can be achieved in detecting both colorectal cancer and significant sized polyps as long as a meticulous technique is adopted while performing CT colonoscopy. Furthermore, it is important to realize that there is a learning curve involved in interpreting these studies and adequate experience is essential to achieve high sensitivity and specificity with this technique. Indications, contraindications, technique and interpretation, including potential pitfalls in CT colonoscopy imaging, are reviewed in this article. Recent advances and the current role of CT colonoscopy in colorectal cancer screening are also discussed.
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23
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Yee J, Weinstein S, Morgan T, Alore P, Aslam R. Advances in CT Colonography for Colorectal Cancer Screening and Diagnosis. J Cancer 2013; 4:200-9. [PMID: 23459511 PMCID: PMC3584833 DOI: 10.7150/jca.5858] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 02/07/2013] [Indexed: 12/13/2022] Open
Abstract
CT colonography (CTC) is a validated colorectal cancer test that provides an additional minimally-invasive screening option which is likely to be preferred by some patients. Important examination prerequisites include adequate colonic cleansing and distention. Tagging of residual material aids in the differentiation of true polyps from stool. Low radiation dose technique should be employed routinely for screening studies. Readers must be skilled in the use of both 2D and 3D interpretation methods.
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Affiliation(s)
- Judy Yee
- Dept. of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94121, USA
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24
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Simons PCG, Van Steenbergen LN, De Witte MT, Janssen-Heijnen MLG. Miss rate of colorectal cancer at CT colonography in average-risk symptomatic patients. Eur Radiol 2012; 23:908-13. [DOI: 10.1007/s00330-012-2679-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/03/2012] [Accepted: 09/15/2012] [Indexed: 12/24/2022]
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25
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Mang T, Gryspeerdt S, Schima W, Lefere P. Evaluation of colonic lesions and pitfalls in CT colonography: a systematic approach based on morphology, attenuation and mobility. Eur J Radiol 2012; 82:1177-86. [PMID: 22817848 DOI: 10.1016/j.ejrad.2012.05.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Accepted: 05/23/2012] [Indexed: 02/06/2023]
Abstract
Computed tomographic colonography is a reliable technique for the detection and classification of neoplastic and non-neoplastic lesions of the colon. It is based on a thin-section CT dataset of the cleansed and air-distended colon, acquired in prone and supine position. Two-dimensional and 3D projections are used in combination for image interpretation. The evaluation of CT colonography datasets is based on two steps, lesion perception to detect a polyp candidate and image interpretation to correctly characterize colonic filling defects. A thorough knowledge of the morphologic and attenuation characteristics of common colonic lesions and artifacts facilitates characterization of the findings. The purpose of this review article is to give an overview of the key CT colonographic imaging criteria to correctly characterize common colorectal lesions and to identify typical pitfalls and pseudolesions.
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Affiliation(s)
- Thomas Mang
- Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
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26
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Boellaard TN, de Haan MC, Venema HW, Stoker J. Colon distension and scan protocol for CT-colonography: an overview. Eur J Radiol 2011; 82:1144-58. [PMID: 22154604 DOI: 10.1016/j.ejrad.2011.10.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 10/31/2011] [Indexed: 12/18/2022]
Abstract
This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a thin, flexible catheter. Hyoscine butylbromide is - when available - the preferred spasmolytic agent because of the positive effect on insufflation and pain/burden and its low costs. Scans in two positions are required for adequate distension and high polyp sensitivity and decubitus position may be used as an alternative for patients unable to lie in prone position. The great intrinsic contrast between air or tagging and polyps allows the use of low radiation dose. Low-dose protocol without intravenous contrast should be used when extracolonic findings are deemed unimportant. In patients suspected for colorectal cancer, normal abdominal CT scan protocols and intravenous contrast should be used in supine position for the evaluation of extracolonic findings. Dose reduction can be obtained by lowering the tube current and/or voltage. Tube current modulation reduces the radiation dose (except in obese patients), and should be used when available. Iterative reconstructions is a promising dose reducing tool and dual-energy CT is currently evaluated for its applications in CT-colonography. This review also provides our institution's insufflation procedure and scan parameters.
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Affiliation(s)
- Thierry N Boellaard
- Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam, The Netherlands.
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27
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Buchach CM, Kim DH, Pickhardt PJ. Performing an additional decubitus series at CT colonography. ABDOMINAL IMAGING 2011; 36:538-44. [PMID: 21184064 PMCID: PMC5514551 DOI: 10.1007/s00261-010-9666-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE To determine the rate and associated factors for acquiring a decubitus series at CT colonography (CTC), in addition to the standard supine and prone series. MATERIALS AND METHODS CTC examinations read centrally at one institution but performed at three different centers in 6,380 adults were reviewed to determine the frequency of an additional decubitus series. Results were analyzed according to study indication (primary screening vs. diagnostic for incomplete colonoscopy), practice site (academic vs. community), patient age, gender, body mass index (BMI), and temporal variation. At all sites, the CT technologist determined the need for an additional decubitus series, with infrequent radiologist input in select cases. RESULTS The frequency for the CT technologist to obtain a decubitus series at screening was 9.7% (578/5,952), compared with 22.9% (98/428) following failed colonoscopy (P < 0.001). The decubitus rate for screening at the academic center (9.4%, 550/5,871) was significantly lower than the community hospitals (34.6% combined, 28/81) (P < 0.001). The rate progressively increased with age, from 5.0% under age 50 to 28.0% over age 80. No significant difference was seen between men and women (10.3 vs. 9.2%), but a strong correlation existed with increased BMI, rising to >25% for BMI over 40. Marked temporal variation existed at the academic center, with quarterly rates ranging from 0 to 17%. CONCLUSIONS The frequency for performing a third series at CTC varies considerably according to indication, practice site, patient age, BMI, and time. These results have important implications for clinical practice, including the need for improved training and feedback for CT technologists.
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Affiliation(s)
- Christopher M Buchach
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Clinical Science Center, Madison, 53792-3252, USA
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28
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Pagés Llinás M, Darnell Martín A, Ayuso Colella J. CT colonography: What radiologists need to know. RADIOLOGIA 2011. [DOI: 10.1016/j.rxeng.2011.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Pagés Llinás M, Darnell Martín A, Ayuso Colella JR. [CT colonography: what radiologists need to know]. RADIOLOGIA 2011; 53:315-25. [PMID: 21696795 DOI: 10.1016/j.rx.2011.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/11/2010] [Accepted: 01/20/2011] [Indexed: 02/06/2023]
Abstract
In 2008, CT colonography was approved by the American Cancer Society as a technique for screening for colorectal cancer. This approval should be considered an important step in the recognition of the technique, which although still relatively new is already changing some diagnostic algorithms. This update about CT colonography reports the quality parameters necessary for a CT colonographic study to be diagnostic and reviews the technical innovations and colonic preparation for the study. We provide a brief review of the signs and close with a discussion of the current indications for and controversies about the technique.
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Affiliation(s)
- M Pagés Llinás
- Centro de Diagnóstico por la Imagen, Hospital Clínic de Barcelona, Barcelona, España.
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CT colonography with limited bowel preparation for the detection of colorectal neoplasia in an FOBT positive screening population. ACTA ACUST UNITED AC 2011; 35:661-8. [PMID: 19888629 PMCID: PMC2980629 DOI: 10.1007/s00261-009-9586-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Purpose Aim was to evaluate the accuracy of computed tomography colonography (CTC) for detection of colorectal neoplasia in a Fecal Occult Blood Test (FOBT) positive screening population. Methods In three different institutions, consecutive FOBT positives underwent CTC after laxative free iodine tagging bowel preparation followed by colonoscopy with segmental unblinding. Each CTC was read by two experienced observers. For CTC and for colonoscopy the per-polyp sensitivity and per-patient sensitivity and specificity were calculated for detection of carcinomas, advanced adenomas, and adenomas. Results In total 22 of 302 included FOBT positive participants had a carcinoma (7%) and 137 had an adenoma or carcinoma ≥10 mm (45%). CTC sensitivity for carcinoma was 95% with one rectal carcinoma as false negative finding. CTC sensitivity for advanced adenomas was 92% (95% CI: 88–96) vs. 96% (95% CI: 93–99) for colonoscopy (P = 0.26). For adenomas and carcinomas ≥10 mm the CTC per-polyp sensitivity was 93% (95% CI: 89–97) vs. 97% (95% CI: 94–99) for colonoscopy (P = 0.17). The per-patient sensitivity for the detection of adenomas and carcinomas ≥10 mm was 95% (95% CI: 91–99) for CTC vs. 99% (95% CI: 98–100) for colonoscopy (P = 0.07), while the per-patient specificity was 90% (95% CI: 86–95) and 96% (95% CI: 94–99), respectively (P < 0.001). Conclusion CTC with limited bowel preparation performed in an FOBT positive screening population has high diagnostic accuracy for the detection of adenomas and carcinomas and a sensitivity similar to that of colonoscopy for relevant lesions.
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East JE, Bassett P, Arebi N, Thomas-Gibson S, Guenther T, Saunders BP. Dynamic patient position changes during colonoscope withdrawal increase adenoma detection: a randomized, crossover trial. Gastrointest Endosc 2011; 73:456-63. [PMID: 20950801 DOI: 10.1016/j.gie.2010.07.046] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 07/26/2010] [Indexed: 12/14/2022]
Abstract
BACKGROUND Colonoscopy has a miss rate for adenomas that may partly relate to poor visualization of the colonic surface. Dynamic position changes during colonoscope withdrawal can improve luminal distension. OBJECTIVE To assess whether position changes also improve adenoma and polyp detection. DESIGN Randomized crossover clinical trial. SETTING Academic endoscopy unit. PATIENTS This study involved 130 patients who presented for routine colonoscopy. INTERVENTION Examination either entirely in the left lateral position followed by position changes (cecum to hepatic flexure, left lateral; transverse colon, supine; splenic flexure and descending colon, right lateral) or vice versa. After both examinations, polyps were removed for histopathology. MAIN OUTCOME MEASUREMENTS Proportion of patients with ≥1 polyp or adenoma detected between the hepatic flexure and the sigmoid-descending colon junction. Luminal distension was measured on a scale of 1 to 5: 1, total collapse; 5, fully distended. RESULTS At least 1 adenoma was detected in 34% of patients in colon areas in which the patient position differed from left lateral (transverse colon, splenic flexure, descending colon) compared with 23% examined with the patient in the left lateral position alone (P = .01). At least 1 polyp was detected in 52% of patients with position changes versus 34% of patients examined in the left lateral position alone (P < .001). Adenoma and polyp detection were positively correlated with an improved distension score (correlation coefficient, 0.12; P < .001). Adenomas were detected in 16% of colon areas with adequate distension scores (4 and 5) compared with 7% of those with borderline or nondiagnostic scores (1-3; P < .001). LIMITATIONS Single-operator study. CONCLUSION Dynamic position changes during colonoscope withdrawal significantly improved polyp and adenoma detection. ( CLINICAL TRIAL REGISTRATION NUMBER NCT00234650).
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Affiliation(s)
- James E East
- Wolfson Unit for Endoscopy, St. Mark’s Hospital, Imperial College London, London.
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Summers RM, Baecher N, Yao J, Liu J, Pickhardt PJ, Choi JR, Hill S. Feasibility of simultaneous computed tomographic colonography and fully automated bone mineral densitometry in a single examination. J Comput Assist Tomogr 2011; 35:212-6. [PMID: 21412092 PMCID: PMC3077119 DOI: 10.1097/rct.0b013e3182032537] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To show the feasibility of calculating the bone mineral density (BMD) from computed tomographic colonography (CTC) scans using fully automated software. MATERIALS AND METHODS Automated BMD measurement software was developed that measures the BMD of the first and second lumbar vertebrae on computed tomography and calculates the mean of the 2 values to provide a per patient BMD estimate. The software was validated in a reference population of 17 consecutive women who underwent quantitative computed tomography and in a population of 475 women from a consecutive series of asymptomatic patients enrolled in a CTC screening trial conducted at 3 medical centers. RESULTS The mean (SD) BMD was 133.6 (34.6) mg/mL (95% confidence interval, 130.5-136.7; n = 475). In women aged 42 to 60 years (n = 316) and 61 to 79 years (n = 159), the mean (SD) BMDs were 143.1 (33.5) and 114.7 (28.3) mg/mL, respectively (P < 0.0001). Fully automated BMD measurements were reproducible for a given patient with 95% limits of agreement of -9.79 to 8.46 mg/mL for the mean difference between paired assessments on supine and prone CTC. CONCLUSIONS Osteoporosis screening can be performed simultaneously with screening for colorectal polyps.
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Affiliation(s)
- Ronald M Summers
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences Department, National Institutes of Health Clinical Center, Bethesda, MD 20892-1182, USA.
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From good to great: further thoughts on improving quality during routine colonoscopy. Gastrointest Endosc 2011; 73:464-6. [PMID: 21353843 DOI: 10.1016/j.gie.2010.08.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 08/30/2010] [Indexed: 02/08/2023]
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Slater A, North M, Hart M, Ferrett C. Gas insufflation of minimal preparation CT of the colon reduces false-positives. Br J Radiol 2011; 85:346-50. [PMID: 21224295 DOI: 10.1259/bjr/20678489] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
OBJECTIVES Minimal preparation CT of the colon (MPCT colon) is used for investigation of suspected colorectal cancer in frail and/or elderly patients who would be expected to tolerate laxative bowel preparation poorly. Although it has good sensitivity for colorectal cancer it has a poor specificity. We wished to investigate whether distension of the colon with carbon dioxide alone would reduce the number of false-positives, but without making the test arduous or excessively uncomfortable. METHODS 134 patients were recruited and underwent MPCT colon with gas insufflation and antispasmodics. Results were compared with a cohort of 134 patients undergoing standard protocol MPCT colon. The numbers of false-positives were compared, as was reader confidence. All trial patients were given a questionnaire documenting their experience. RESULTS The number of false-positives was 15% in the control group and 5% in the trial group; this difference was statistically significant, (p=0.01). Reader confidence was increased in the trial group. Patient tolerance was good, with 95% saying they would have the test again. CONCLUSION Use of gas insufflation and antispasmodics reduces the false-positives from 15% to 5% without adversely affecting patient tolerance.
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Affiliation(s)
- A Slater
- John Radcliffe Hospital, Headley Way, Headington, Oxford, UK.
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Robinson C, Halligan S, Iinuma G, Topping W, Punwani S, Honeyfield L, Taylor SA. CT colonography: computer-assisted detection of colorectal cancer. Br J Radiol 2010; 84:435-40. [PMID: 21081583 DOI: 10.1259/bjr/17848340] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES Computer-aided detection (CAD) for CT colonography (CTC) has been developed to detect benign polyps in asymptomatic patients. We aimed to determine whether such a CAD system can also detect cancer in symptomatic patients. METHODS CTC data from 137 symptomatic patients subsequently proven to have colorectal cancer were analysed by a CAD system at 4 different sphericity settings: 0, 50, 75 and 100. CAD prompts were classified by an observer as either true-positive if overlapping a cancer or false-positive if elsewhere. Colonoscopic data were used to aid matching. RESULTS Of 137 cancers, CAD identified 124 (90.5%), 122 (89.1%), 119 (86.9%) and 102 (74.5%) at a sphericity of 0, 50, 75 and 100, respectively. A substantial proportion of cancers were detected on either the prone or supine acquisition alone. Of 125 patients with prone and supine acquisitions, 39.3%, 38.3%, 43.2% and 50.5% of cancers were detected on a single acquisition at a sphericity of 0, 50, 75 and 100, respectively. CAD detected three cancers missed by radiologists at the original clinical interpretation. False-positive prompts decreased with increasing sphericity value (median 65, 57, 45, 24 per patient at values of 0, 50, 75, 100, respectively) but many patients were poorly prepared. CONCLUSION CAD can detect symptomatic colorectal cancer but must be applied to both prone and supine acquisitions for best performance.
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Affiliation(s)
- C Robinson
- Centre for Medical Imaging, University College Hospital, London, UK
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Sabanli M, Balasingam A, Bailey W, Eglinton T, Hider P, Frizelle FA. Computed tomographic colonography in the diagnosis of colorectal cancer. Br J Surg 2010; 97:1291-4. [PMID: 20602504 DOI: 10.1002/bjs.7098] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND This study aimed to determine the sensitivity of computed tomographic colonography (CTC) in diagnosing colorectal cancer and to explore the reasons why these cancers are missed on CTC. METHODS Patients who underwent CTC in the 56-month period from 1 January 2004 to 1 September 2008, and all cases of colorectal cancer recorded in the National Cancer Registry database from 1 January 2004 to 1 December 2008, were identified. Cases from the two data sets were then matched to identify all patients in whom CTC had been performed more than 6 weeks before a histological report was available. CTC reports and patients' records were reviewed to determine the cancer site, and images were reviewed. RESULTS A total of 3888 patients underwent CTC over a 56-month interval. After matching with the National Cancer Registry database, colorectal cancer was identified in 131 patients, whereas it had been suspected on CTC in 123 patients. One of the patients with missed cancer was excluded, leaving seven (5.3 per cent) missed cancers, four of which were located in the caecum. Five cancers were missed because of technical limitations of CTC and two were due to perceptive errors. Systems errors and severe patient co-morbidity contributed to three of the cases. The sensitivity of CTC for colorectal cancer was 95 (95 per cent confidence interval 89 to 98) per cent. CONCLUSION The sensitivity of 95 per cent for CTC in the diagnosis of colorectal cancer compares favourably with that of double-contrast barium enema (92 per cent) and colonoscopy (94 per cent).
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Affiliation(s)
- M Sabanli
- Department of Surgery, Christchurch Hospital, Christchurch, New Zealand
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Ascending colon rotation following patient positional change during CT colonography: a potential pitfall in interpretation. Eur Radiol 2010; 21:353-9. [DOI: 10.1007/s00330-010-1928-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 07/09/2010] [Accepted: 07/28/2010] [Indexed: 12/22/2022]
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Abstract
Computed tomographic colonography (CTC) has emerged as an alternative screening tool for colorectal cancer due to the potential to provide good efficacy combined with greater acceptability than optical colonoscopy or fecal occult blood testing. However, some organizations have raised concerns about the potential harms, including perforation rates and radiation-related cancer risks, and have not recommended that it currently be used as a screening tool in the general population in the US. In this article the authors review the current evidence for these potential harms from CTC and compare them to the potential harms from the alternatives including colonoscopy and double-contrast barium enema.
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Affiliation(s)
| | - Kwang Pyo Kim
- Department of Nuclear Engineering, Kyung Hee University, 1 Seocheondong, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Judy Yee
- University of California, San Francisco, VA Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA.
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Abstract
Computed tomographic colonography (CTC) is a validated tool for the evaluation of the colon for polyps and cancer. The technique employed for CTC includes a low-dose CT scan of the abdomen and pelvis that is typically performed without the administration of intravenous contrast. Using this technique it is possible to discover findings outside of the colon. By far, most extracolonic findings are determined to be clinically inconsequential on CTC and most patients are not recommended for further testing. However, some findings may result in additional diagnostic evaluation or intervention, which can lead to patient anxiety and increased morbidity and health care costs. Alternatively, some findings can lead to the earlier diagnosis of a clinically significant lesion, which could result in decreased patient morbidity and mortality as well as overall savings in downstream health care costs. The controversies of detecting and evaluating these incidental extracolonic findings on CTC are discussed.
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40
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Current techniques in the performance, interpretation, and reporting of CT colonography. Gastrointest Endosc Clin N Am 2010; 20:169-92. [PMID: 20451809 DOI: 10.1016/j.giec.2010.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The technical objective of computed tomographic colonography (CTC) is to acquire high-quality computed tomography images of the cleansed, well-distended colon for polyp detection. In this article the authors provide an overview of the technical components of CTC, from preparation of the patient to acquisition of the imaging data and basic methods of interpretation. In each section, the best evidence for current practices and recommendations is reviewed. Each of the technical components must be optimized to achieve high sensitivity in polyp detection.
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Wang S, Yao J, Liu J, Petrick N, Van Uitert RL, Periaswamy S, Summers RM. Registration of prone and supine CT colonography scans using correlation optimized warping and canonical correlation analysis. Med Phys 2010; 36:5595-603. [PMID: 20095272 DOI: 10.1118/1.3259727] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE In computed tomographic colonography (CTC), a patient will be scanned twice-Once supine and once prone-to improve the sensitivity for polyp detection. To assist radiologists in CTC reading, in this paper we propose an automated method for colon registration from supine and prone CTC scans. METHODS We propose a new colon centerline registration method for prone and supine CTC scans using correlation optimized warping (COW) and canonical correlation analysis (CCA) based on the anatomical structure of the colon. Four anatomical salient points on the colon are first automatically distinguished. Then correlation optimized warping is applied to the segments defined by the anatomical landmarks to improve the global registration based on local correlation of segments. The COW method was modified by embedding canonical correlation analysis to allow multiple features along the colon centerline to be used in our implementation. RESULTS We tested the COW algorithm on a CTC data set of 39 patients with 39 polyps (19 training and 20 test cases) to verify the effectiveness of the proposed COW registration method. Experimental results on the test set show that the COW method significantly reduces the average estimation error in a polyp location between supine and prone scans by 67.6%, from 46.27 +/- 52.97 to 14.98 mm +/- 11.41 mm, compared to the normalized distance along the colon centerline algorithm (p < 0.01). CONCLUSIONS The proposed COW algorithm is more accurate for the colon centerline registration compared to the normalized distance along the colon centerline method and the dynamic time warping method. Comparison results showed that the feature combination of z-coordinate and curvature achieved lowest registration error compared to the other feature combinations used by COW. The proposed method is tolerant to centerline errors because anatomical landmarks help prevent the propagation of errors across the entire colon centerline.
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Affiliation(s)
- Shijun Wang
- Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, Maryland 20892-1182, USA.
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Suh JW, Wyatt CL. Deformable registration of supine and prone colons for computed tomographic colonography. J Comput Assist Tomogr 2010; 33:902-11. [PMID: 19940658 DOI: 10.1097/rct.0b013e3181a7e2c1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Computed tomographic colonography is a minimally invasive technique for detecting colorectal polyps and colon cancer. Most computed tomographic colonography protocols acquire both prone and supine images to improve the visualization of the lumen wall, reduce false-positives, and improve sensitivity. Comparisons between the prone and supine images can be improved by registration between the scans. In this paper, we propose registering colon lumens, segmented from prone and supine images, using feature matching of the colon centerline and nonrigid registration of the lumen shapes represented as distance functions. Experimental registration results (n = 21 subjects) show a correspondence accuracy of 13.77 +/- 6.20 mm for a range of polyp sizes. The overlap in the registered lumen segmentations show an average Jaccard similarity coefficient of 0.915 +/- 0.07.
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Affiliation(s)
- Jung W Suh
- Diagnostic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA.
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McFarland EG, Fletcher JG, Pickhardt P, Dachman A, Yee J, McCollough CH, Macari M, Knechtges P, Zalis M, Barish M, Kim DH, Keysor KJ, Johnson CD. ACR Colon Cancer Committee white paper: status of CT colonography 2009. J Am Coll Radiol 2010; 6:756-772.e4. [PMID: 19878883 DOI: 10.1016/j.jacr.2009.09.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Accepted: 09/02/2009] [Indexed: 12/21/2022]
Abstract
PURPOSE To review the current status and rationale of the updated ACR practice guidelines for CT colonography (CTC). METHODS Clinical validation trials in both the United States and Europe are reviewed. Key technical aspects of the CTC examination are emphasized, including low-dose protocols, proper insufflation, and bowel preparation. Important issues of implementation are discussed, including training and certification, definition of the target lesion, reporting of colonic and extracolonic findings, quality metrics, reimbursement, and cost-effectiveness. RESULTS Successful validation trials in screening cohorts both in the United States with ACRIN and in Germany demonstrated sensitivity > or = 90% for patients with polyps >10 mm. Proper technique is critical, including low-dose techniques in screening cohorts, with an upper limit of the CT dose index by volume of 12.5 mGy per examination. Training new readers includes the requirement of interactive workstation training with 2-D and 3-D image display techniques. The target lesion is defined as a polyp > or = 6 mm, consistent with the American Cancer Society joint guidelines. Five quality metrics have been defined for CTC, with pilot data entered. Although the CMS national noncoverage decision in May 2009 was a disappointment, multiple third-party payers are reimbursing for screening CTC. Cost-effective modeling has shown CTC to be a dominant strategy, including in a Medicare cohort. CONCLUSION Supported by third-party payer reimbursement for screening, CTC will continue to further transition into community practice and can provide an important adjunctive examination for colorectal screening.
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Abstract
An examination technique adapted to comply with the demands of CT colonography is not only a basic requirement for a high-quality examination and correct ascertainment of the findings; it is also essential for far-reaching applications of this method of examination. The technique of CT colonography is based on good patient preparation with the aid of fecal tagging, adequate distension of the colon with CO(2) and acquisition of data with the patient both prone and supine in a thin-slice technique using a low-dose protocol. The different technical aspects of CT colonography are explained in this paper.
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PUNWANI S, HALLIGAN S, TOLAN D, TAYLOR SA, HAWKES D. Quantitative assessment of colonic movement between prone and supine patient positions during CT colonography. Br J Radiol 2009; 82:475-81. [DOI: 10.1259/bjr/91937173] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Abstract
CT colonography (CTC), also termed virtual colonoscopy, is increasingly accepted at sites throughout the world as a new effective tool for the diagnosis and screening of colorectal carcinoma. This article presents information of related issues of bowel cleansing, stool and fluid tagging, bowel distention and multidetector CT scanning parameters. The author presents discussion of interpretation of CTC, appropriate applications of CTC and potential complications.
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Affiliation(s)
- Judy Yee
- University of California, San Francisco, VA Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA.
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Abstract
The focus on colorectal neoplasia has led to an exponential increase in the use of colonoscopy in many countries. Although colonoscopy facilitates the diagnosis and treatment of colonic disease, there are public health issues that include access, training, diagnostic accuracy, complications and additions to health-care costs. Because of this, colonoscopists have a responsibility to ensure that the procedure is appropriate, safe and of high-quality. This article addresses the issue of variation in technical skills that is known to exist within the endoscopic community, even among individuals with similar experience. While some of this variation reflects innate manual dexterity, another aspect is variation in the adoption of technical manoeuvers that facilitate various aspects of the procedure including rates for cecal intubation. Although technical manoeuvers are difficult to evaluate in controlled trials, there is persuasive data that high cecal intubation rates can be achieved by minimizing inflation and looping in the sigmoid colon and by the appropriate use of positional changes and abdominal pressure. In difficult settings, there is also benefit from the use of non-standard endoscopes and various accessories including overtubes.
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Affiliation(s)
- Ian C Roberts-Thomson
- Department of Gastroenterology and Hepatology, The Queen Elizabeth Hospital, Woodville South, South Australia 5011 Australia.
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48
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CT colonography can be an adjunct to optical colonoscopy in CRC screening. Dig Dis Sci 2009; 54:212-7. [PMID: 18612821 DOI: 10.1007/s10620-008-0360-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Accepted: 06/03/2008] [Indexed: 01/22/2023]
Abstract
CT colonography or virtual colonoscopy is a fairly new modality that has the potential to play a significant role in screening for colon cancer. CT colonography is an attractive option for two specific reasons. First, it is non-invasive and, second, it obviates the need for sedation. It thus overcomes the two major drawbacks of optical colonoscopy. CT colonography cannot be a stand-alone technique for colorectal cancer screening because, unlike conventional colonoscopy, it does not possess a therapeutic option or a definite diagnostic capability. However, CT colonography can be a cost-effective complement to traditional colonoscopy if it is reasonably priced and if appropriate cut-off levels (>6 mm polyp) are used to increase its sensitivity.
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Comparison of polyp distance on CT colonography between supine and prone scans using an automated path-distance measurement tool: correlation with colonoscopy. ACTA ACUST UNITED AC 2008; 35:41-8. [PMID: 19089490 DOI: 10.1007/s00261-008-9484-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Accepted: 11/12/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To investigate the proximity of polyp distance on CT colonography (CTC) between supine and prone scans using an automated path-distance measurement tool and to correlate the path distance of polyps with that of colonoscopy. METHODS Of 196 polyps in 85 patients, 98 polyps (25 <6 mm, 42 6-9.9 mm, 31 > or =10 mm) detected on supine and prone positions in 72 patients, were included. The location of each polyp, which was expressed as the distance from the tip of the rectum, was measured using an automated path-distance measurement tool and was compared between the two positions. The effect of colonic collapse on the proximity of polyp distance between the two scans was analyzed. The automated path distance of 50 polyps in the rectosigmoid colon was correlated with that of colonoscopy. RESULTS Mean difference of the automated path distances of polyps between the two positions was 2.6 cm and was not significantly different between the two positions (P > 0.05). Correlation coefficient (gamma) between the two positions was 0.9977. The difference of the distance of polyps between the groups with or without colonic collapse was not significant (P > 0.05). Automated path distance of 50 polyps in the sigmoid colon or rectum was generally well correlated with that on colonoscopy (gamma = 0.8005, P < 0.0001) and the mean difference was 5.1 cm. The mean difference increased as the polyp distance from the point of reference became further located, and reached significance when the distance was further than 30 cm from the tip of the rectum (P = 0.002). CONCLUSION Automated path distance of polyps matches closely between the two positions and is not influenced by the presence of collapsed segments. Polyps located 30 cm or further from the tip of the rectum on CTC do not match closely with that on colonoscopy.
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Abstract
OBJECTIVE The purpose of this study was to prospectively evaluate the effect of the order of positions on sustained rectal pressure and factors affecting pain perceived by patients during air-insufflated CT colonography. SUBJECTS AND METHODS Rectal pressure was measured in the supine and prone positions for CT colonography of 379 patients in two groups. One hundred seventy-seven patients underwent imaging supine and then prone, and 202 patients were prone and then supine. Insufflation and patient pain parameters were based on patient self-report and investigator visualization of observable indicators. Colonic distention, residual feces or fluid, and diverticulosis were evaluated with a semiquantitative scoring system. Fisher's exact, Student's t, and chi-square tests as well as multivariate logistic regression analysis were performed. RESULTS Pressure was higher in the prone than in the supine position in both groups (p < 0.001). The measured pressure in the initial position did not differ between groups (p = 0.88). Pressure increased from 38.3 to 40.07 mm Hg in the second position in the supine-first group and decreased from 38.3 to 32.25 mm Hg in the second position in the prone-first group (p < 0.001). The percentage of patients with pain in the second position was 40% in the supine-first group compared with 18% in the prone-first group (p < 0.003). Distention did not differ between the groups. Pain was associated with increased pressure and diverticulosis (p < 0.001) but not with retained feces or fluid. CONCLUSION Sustained pressure in the air-insufflated colon was higher in the prone than in the supine position. Imaging in the prone position first results in a significant decrease in pressure in the latter phase and less pain. Pain was associated with pressure and diverticulosis.
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