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Kim SH, Kim JY, Hwang MJ. Magnetic Resonance Elastography for the Detection and Classification of Prostate Cancer. Cancers (Basel) 2024; 16:3494. [PMID: 39456588 PMCID: PMC11505984 DOI: 10.3390/cancers16203494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2024] [Revised: 10/12/2024] [Accepted: 10/13/2024] [Indexed: 10/28/2024] Open
Abstract
We investigated the feasibility of magnetic resonance elastography (MRE) using a pelvic acoustic driver for the detection and classification of prostate cancer (PCa). A total of 75 consecutive patients (mean age, 70; range, 56-86) suspected of having PCa and who underwent multi-parametric MRI including MRE and subsequent surgical resection were included. The analyzed regions consisted of cancer (n = 69), benign prostatic hyperplasia (BPH) (n = 70), and normal parenchyma (n = 70). A histopathologic topographic map served as the reference standard for each region. One radiologist and one pathologist performed radiologic-pathologic correlation, and the radiologist measured stiffness values in each region of interest on elastograms automatically generated by dedicated software. Paired t-tests were used to compare stiffness values between two regions. ROC curve analysis was also used to extract a cutoff value between two regions. The stiffness value of PCa (unit, kilopascal (kPa); 4.9 ± 1.1) was significantly different to that of normal parenchyma (3.6 ± 0.3, p < 0.0001) and BPH (4.5 ± 1.4, p = 0.0454). Under a cutoff value of 4.2 kPa, a maximum accuracy of 87% was estimated, with a sensitivity of 73%, a specificity of 99%, and an AUC of 0.839 for discriminating PCa from normal parenchyma. Between PCa and BPH, a maximum accuracy of 62%, a sensitivity of 70%, a specificity of 56%, and an AUC of 0.598 were estimated at a 4.5 kPa cutoff. The stiffness values tended to increase as the ISUP grade increased. In conclusion, it is feasible to detect and classify PCa using pelvic MRE. Our observations suggest that MRE could be a supplement to multi-parametric MRI for PCa detection.
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Affiliation(s)
- Seung Ho Kim
- Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan 48108, Republic of Korea
| | - Joo Yeon Kim
- Department of Pathology, Inje University College of Medicine, Haeundae Paik Hospital, Busan 48108, Republic of Korea;
| | - Moon Jung Hwang
- Advanced Medical Imaging Institute, Korea University Anam Hospital, Seoul 02841, Republic of Korea;
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Lee HJ, Cho SB, Lee JK, Kim JS, Oh CH, Kim HJ, Yoon H, Ahn HK, Kim M, Hwang YG, Kwon HY, Hwang MJ. The feasibility of MR elastography with transpelvic vibration for localization of focal prostate lesion. Sci Rep 2024; 14:3864. [PMID: 38366042 PMCID: PMC10873507 DOI: 10.1038/s41598-024-54341-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/12/2024] [Indexed: 02/18/2024] Open
Abstract
We aimed to evaluate the feasibility of MR elastography (MRE) using a transpelvic approach. Thirty-one patients who underwent prostate MRE and had a pathological diagnosis were included in this study. MRE was obtained using a passive driver placed at the umbilicus and iliac crests. The shear stiffness, clinical data, and conventional imaging findings of prostate cancer and benign prostatic hyperplasia (BPH) were compared. Inter-reader agreements were evaluated using the intraclass coefficient class (ICC). Prostate MRE was successfully performed for all patients (100% technical success rate). Nineteen cancer and 10 BPH lesions were visualized on MRE. The mean shear stiffness of cancer was significantly higher than that of BPH (5.99 ± 1.46 kPa vs. 4.67 ± 1.54 kPa, p = 0.045). One cancer was detected on MRE but not on conventional sequences. Six tiny cancer lesions were not visualized on MRE. The mean size of cancers that were not detected on MRE was smaller than that of cancers that were visible on MRE (0.8 ± 0.3 cm vs. 2.3 ± 1.8 cm, p = 0.001). The inter-reader agreement for interpreting MRE was excellent (ICC = 0.95). Prostate MRE with transpelvic vibration is feasible without intracavitary actuators. Transpelvic prostate MRE is reliable for detecting focal lesions, including clinically significant prostate cancer and BPH.
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Affiliation(s)
- Hyo Jeong Lee
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Soo Buem Cho
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea.
| | - Jeong Kyong Lee
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Jin Sil Kim
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Chang Hoon Oh
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hyun Jin Kim
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hana Yoon
- Department of Urology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hyun Kyu Ahn
- Department of Urology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Myong Kim
- Department of Urology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Yeok Gu Hwang
- Department of Orthopedic Surgery, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hye Young Kwon
- Department of Radiology, Chungnam National University College of Medicine, Daejeon, South Korea
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Tardieu M, Salameh N, Souris L, Rousseau D, Jourdain L, Skeif H, Prévot F, de Rochefort L, Ducreux D, Louis B, Garteiser P, Sinkus R, Darrasse L, Poirier-Quinot M, Maître X. Magnetic resonance elastography with guided pressure waves. NMR IN BIOMEDICINE 2022; 35:e4701. [PMID: 35088465 DOI: 10.1002/nbm.4701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Magnetic resonance elastography aims to non-invasively and remotely characterize the mechanical properties of living tissues. To quantitatively and regionally map the shear viscoelastic moduli in vivo, the technique must achieve proper mechanical excitation throughout the targeted tissues. Although it is straightforward, ante manibus, in close organs such as the liver or the breast, which practitioners clinically palpate already, it is somewhat fortunately highly challenging to trick the natural protective barriers of remote organs such as the brain. So far, mechanical waves have been induced in the latter by shaking the surrounding cranial bones. Here, the skull was circumvented by guiding pressure waves inside the subject's buccal cavity so mechanical waves could propagate from within through the brainstem up to the brain. Repeatable, reproducible and robust displacement fields were recorded in phantoms and in vivo by magnetic resonance elastography with guided pressure waves such that quantitative mechanical outcomes were extracted in the human brain.
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Affiliation(s)
- Marion Tardieu
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
- Montpellier Cancer Research Institute (IRCM), Inserm U1194, University of Montpellier, Montpellier, France
| | - Najat Salameh
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
- Center for Adaptable MRI Technology, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Line Souris
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | | | - Laurène Jourdain
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | - Hanadi Skeif
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | - François Prévot
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | - Ludovic de Rochefort
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
- Aix-Marseille Université, CNRS, CRMBM, Marseille, France
- AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Denis Ducreux
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | - Bruno Louis
- Inserm-UPEC UMR955, CNRS EMR7000, Equipe Biomécanique Cellulaire et Respiratoire, Créteil, France
| | - Philippe Garteiser
- Laboratory of Imaging Biomarkers, Center for Research on Inflammation, UMR 1149, Inserm, Université de Paris, Paris, France
| | - Ralph Sinkus
- Imaging Sciences & Biomedical Engineering Division, King's College, London, United Kingdom
| | - Luc Darrasse
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | | | - Xavier Maître
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
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Aldoj N, Biavati F, Dewey M, Hennemuth A, Asbach P, Sack I. Fully automated quantification of in vivo viscoelasticity of prostate zones using magnetic resonance elastography with Dense U-net segmentation. Sci Rep 2022; 12:2001. [PMID: 35132102 PMCID: PMC8821548 DOI: 10.1038/s41598-022-05878-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 01/05/2022] [Indexed: 11/13/2022] Open
Abstract
Magnetic resonance elastography (MRE) for measuring viscoelasticity heavily depends on proper tissue segmentation, especially in heterogeneous organs such as the prostate. Using trained network-based image segmentation, we investigated if MRE data suffice to extract anatomical and viscoelastic information for automatic tabulation of zonal mechanical properties of the prostate. Overall, 40 patients with benign prostatic hyperplasia (BPH) or prostate cancer (PCa) were examined with three magnetic resonance imaging (MRI) sequences: T2-weighted MRI (T2w), diffusion-weighted imaging (DWI), and MRE-based tomoelastography, yielding six independent sets of imaging data per patient (T2w, DWI, apparent diffusion coefficient, MRE magnitude, shear wave speed, and loss angle maps). Combinations of these data were used to train Dense U-nets with manually segmented masks of the entire prostate gland (PG), central zone (CZ), and peripheral zone (PZ) in 30 patients and to validate them in 10 patients. Dice score (DS), sensitivity, specificity, and Hausdorff distance were determined. We found that segmentation based on MRE magnitude maps alone (DS, PG: 0.93 ± 0.04, CZ: 0.95 ± 0.03, PZ: 0.77 ± 0.05) was more accurate than magnitude maps combined with T2w and DWI_b (DS, PG: 0.91 ± 0.04, CZ: 0.91 ± 0.06, PZ: 0.63 ± 0.16) or T2w alone (DS, PG: 0.92 ± 0.03, CZ: 0.91 ± 0.04, PZ: 0.65 ± 0.08). Automatically tabulated MRE values were not different from ground-truth values (P>0.05). In conclusion, MRE combined with Dense U-net segmentation allows tabulation of quantitative imaging markers without manual analysis and independent of other MRI sequences and can thus contribute to PCa detection and classification.
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Affiliation(s)
- Nader Aldoj
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Federico Biavati
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Marc Dewey
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,DKTK (German Cancer Consortium), Partner Site Berlin, Berlin, Germany.,Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Anja Hennemuth
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Patrick Asbach
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Deng Y, Yi Z, Zhang T, Hu B, Zhang L, Rajlawot K, Kuang S, He B, Arani A, Chen J, Yin M, Rossman P, Glaser KJ, Venkatesh SK, Ehman RL, Wang J. Magnetic resonance elastography of the prostate in patients with lower urinary tract symptoms: feasibility of the modified driver at high multi-frequencies. Abdom Radiol (NY) 2022; 47:399-408. [PMID: 34635941 DOI: 10.1007/s00261-021-03302-6] [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: 05/05/2021] [Revised: 09/26/2021] [Accepted: 09/28/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE To demonstrate the feasibility and diagnostic value of high-frequency magnetic resonance elastography (MRE) for evaluation of prostatic disease in patients with lower urinary tract symptoms (LUTS). METHODS 41 patients who underwent preoperative prostate MRI and MRE with a modified driver were enrolled retrospectively from May 2016 to September 2021. All were included in the assessment of MRE image quality, using a qualitative visual inspection and a quantitative confidence map. 35 patients (prostate cancer (PCa), n = 13; non-PCa, n = 22) undergoing prostatectomy or biopsy were evaluated for the diagnostic performance of stiffness values. The confidence values and the stiffness values were analyzed by one-way analysis of variance (ANOVA) and independent samples T test, respectively. Area under the receiver operating characteristic (AUROC) analysis was performed. RESULTS Through the qualitative analysis, all MRE acquisitions were successful at 60, 90, 120 and 150 Hz. The quantitative confidence values were significantly lower at 60 Hz (0.683 ± 0.055) and 90 Hz (0.762 ± 0.048) than that at 120 Hz (0.814 ± 0.049) and 150 Hz (0.840 ± 0.049), all P < 0.001. The stiffness of PCa was higher than non-PCa at 90 Hz (P = 0.008), 120 Hz (P < 0.001) and 150 Hz (P < 0.001). The AUCs were 0.773, 0.881 and 0.944, respectively. CONCLUSION Prostate MRE using the modified driver is feasible at 60-150 Hz and image quality is better at higher frequencies. Prostate MRE may be useful and helpful to evaluate prostate diseases in patients with LUTS at higher frequencies; however, further study may be warranted with larger population in future.
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Fukui R, Sasaki K, Kawai K, Taira T, Nozawa H, Kaneko M, Murono K, Emoto S, Iida Y, Ishii H, Yokoyama Y, Anzai H, Sonoda H, Ishihara S. Establishing a novel method for assessing elasticity of internal anal sphincter using ultrasonic real-time tissue elastography. ANZ J Surg 2021; 91:E360-E366. [PMID: 33844397 DOI: 10.1111/ans.16760] [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: 01/05/2021] [Revised: 03/07/2021] [Accepted: 03/08/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Evaluating anorectal function using real-time tissue elastography (RTE) has not been reported. A previous study reported that in the internal anal sphincter (IAS) of surgical specimens of patients with rectal cancer who underwent abdominoperineal resection, there was an increased fibrosis trend in those who underwent pre-operative chemoradiotherapy (CRT) compared with non-CRT. We speculated that CRT might have induced sclerosis of the IAS because of fibrosis. Therefore, we aimed to establish a method of quantitating the degree of IAS hardness using RTE on endoanal ultrasonography. METHODS RTE was performed with freehand manual compression under a defined pressure at the middle anal canal. Using the most compressive point in the strain graph, we traced the region of interest in the IAS. The strain histogram showed a frequency distribution of colours according to the degree of strain (numeric scan ranging from 0 to 255; smaller number indicated harder tissue). We defined the mean of the strain histogram as 'elasticity'. Ten patients with locally advanced rectal cancer who underwent pre-operative CRT were prospectively enrolled. We statistically evaluated the correlation between IAS elasticity and maximum resting pressure (MRP) values both at pre- and post-CRT. MRP was examined concurrently with the examination of IAS elasticity. RESULTS Representativity of elasticity measurements was demonstrated. It revealed a trend: IAS elasticity had a moderate inverse correlation with MRP (r = 0.41, P = 0.07), regardless of whether measurements were made before or after CRT. CONCLUSION We established a completely novel method for the assessment of elasticity of the IAS, using RTE on endoanal ultrasonography.
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Affiliation(s)
- Risa Fukui
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazuhito Sasaki
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazushige Kawai
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tetsuro Taira
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroaki Nozawa
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Manabu Kaneko
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Koji Murono
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shigenobu Emoto
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yuuki Iida
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroaki Ishii
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yuichiro Yokoyama
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Anzai
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hirofumi Sonoda
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Soichiro Ishihara
- Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
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Li M, Guo J, Hu P, Jiang H, Chen J, Hu J, Asbach P, Sack I, Li W. Tomoelastography Based on Multifrequency MR Elastography for Prostate Cancer Detection: Comparison with Multiparametric MRI. Radiology 2021; 299:362-370. [PMID: 33687285 DOI: 10.1148/radiol.2021201852] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background Multiparametric MRI is used for depiction of prostate cancer (PCa) but without consideration of the mechanical alteration of prostatic tissue by cancer. Purpose To investigate the diagnostic performance of stiffness and fluidity quantified with tomoelastography, a multifrequency MR elastography technique, for depiction of PCa compared with multiparametric MRI with Prostate Imaging Reporting and Data System (PI-RADS) version 2.1. Materials and Methods Prospective participants suspected to have PCa and healthy controls (HCs) underwent multiparametric MRI and tomoelastography between March 2019 and July 2020. Tomoelastography maps of shear-wave speed (c) and loss angle (φ) quantified stiffness and fluidity, respectively, for PCa and benign prostatic disease and for the peripheral and transition zones in HCs. Differences between entities and regions were analyzed by using analysis of variance or Kruskal-Wallis test. Diagnostic performance was assessed with area under the receiver operating characteristic curve (AUC) analysis. Results There were 73 participants with PCa (mean age, 72 years ± 7 [standard deviation]), 82 with benign prostatic disease (66 years ± 7), and 53 HCs (41 years ± 14). Mean ± standard deviation of c and φ were higher in PCa (3.4 m/sec ± 0.6 and 1.3 radian ± 0.2, respectively) than in benign prostatic disease (2.6 m/sec ± 0.3 and 1.0 radian ± 0.2, respectively; P < .001) and age-matched HCs (2.2 m/sec ± 0.1 and 0.8 radian ± 0.1, respectively; P < .001). Incorporating c and φ (AUC, 0.95; 95% CI: 0.92, 0.98) improved the diagnostic performance of PI-RADS version 2.1 (AUC, 0.85; 95% CI: 0.80, 0.91; P < .001). Multiparametric MRI combined with c and φ enabled detection of PCa with 95% (78 of 82 non-PCa) specificity, which was significantly higher than with use of multiparametric MRI alone (77% [63 of 82 non-PCa]; P < .001). In regional analysis, c combined with φ enabled differentiation of transition zone PCa from benign prostatic hyperplasia (AUC, 0.91; 95% CI: 0.83, 0.98) and peripheral zone PCa from chronic prostatitis (AUC, 0.94; 95% CI: 0.88, 1.00). Conclusion Use of tomoelastography-quantified stiffness and fluidity improved the diagnostic performance of multiparametric MRI with Prostate Imaging Reporting and Data System version 2.1 in detecting cancer in both the peripheral and transition zones. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Hectors and Lewis in this issue. An earlier incorrect version of this article appeared online. This article was corrected on March 24, 2021.
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Affiliation(s)
- Mengsi Li
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Jing Guo
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Ping Hu
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Huichuan Jiang
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Juan Chen
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Jiaxi Hu
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Patrick Asbach
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Ingolf Sack
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
| | - Wenzheng Li
- From the Departments of Radiology (M.L., P.H., J.C., J.H., W.L.) and Urology (H.J.), Xiangya Hospital, Central South University, National Clinical Research Center for Geriatric Disorders, 410008 Changsha, Hunan Province, China; and Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany (J.G., P.A., I.S.)
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Numano T, Habe T, Ito D, Onishi T, Takamoto K, Mizuhara K, Nishijo H, Igarashi K, Ueki T. A new technique for motion encoding gradient-less MR elastography of the psoas major muscle: A gradient-echo type multi-echo sequence. Magn Reson Imaging 2019; 63:85-92. [PMID: 31425804 DOI: 10.1016/j.mri.2019.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 07/29/2019] [Accepted: 08/15/2019] [Indexed: 11/29/2022]
Abstract
The present study aimed to develop vibration techniques for magnetic resonance (MR) elastography (MRE) of the psoas major muscle (PM). Seven healthy volunteers were included. MRE was performed with motion-encoding gradient (MEG)-less multi-echo MRE sequence, which allows clinicians to perform MRE using conventional MR imaging. In order to transmit mechanical vibration of the pneumatic type to the PM, a long narrow vibration pad was designed using a 3D printer, and the optimum vibration techniques were verified. The vibration pad was placed under the lower back, with the volunteers in the supine position. The results indicated that the PM vibrated well through the transmitted vibration from the lumbar spine, which suggests that the placement of a narrow vibration pad under the supine body, along the lumbar spine, allows the vibration of the PM. The shear modulus of the PM (n = 7) was 1.23 ± 0.09 kPa (mean ± SEM) on the right side and 1.22 ± 0.15 kPa on the left side, with no significant difference (t-test, P > 0.05). Increased stiffness of the muscle due to continuous local contraction may be an important cause of non-specific low back pain (LBP). The present vibration techniques for MRE of the PM provide a quantitative diagnostic tool for changes in muscle stiffness associated with non-specific LBP.
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Affiliation(s)
- Tomokazu Numano
- Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, Japan; Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Japan.
| | - Tetsushi Habe
- Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, Japan
| | - Daiki Ito
- Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, Japan; Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Japan; Office of Radiation Technology, Keio University Hospital, Japan
| | - Takaaki Onishi
- Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, Japan
| | - Koichi Takamoto
- System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | | | - Hisao Nishijo
- System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
| | - Keisuke Igarashi
- Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, Japan
| | - Takamichi Ueki
- Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan University, Japan
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9
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Huang X, Chafi H, Matthews KL, Carmichael O, Li T, Miao Q, Wang S, Jia G. Magnetic resonance elastography of the brain: A study of feasibility and reproducibility using an ergonomic pillow-like passive driver. Magn Reson Imaging 2019; 59:68-76. [PMID: 30858002 DOI: 10.1016/j.mri.2019.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 03/08/2019] [Accepted: 03/08/2019] [Indexed: 01/12/2023]
Abstract
Magnetic resonance elastography (MRE) can be used to noninvasively resolve the displacement pattern of induced mechanical waves propagating in tissue. The goal of this study is to establish an ergonomically flexible passive-driver design for brain MRE, to evaluate the reproducibility of MRE tissue-stiffness measurements, and to investigate the relationship between tissue-stiffness measurements and driver frequencies. An ergonomically flexible passive pillow-like driver was designed to induce mechanical waves in the brain. Two-dimensional finite-element simulation was used to evaluate mechanical wave propagation patterns in brain tissues. MRE scans were performed on 10 healthy volunteers at mechanical frequencies of 60, 50, and 40 Hz. An axial mid-brain slice was acquired using an echo-planar imaging sequence to map the displacement pattern with the motion-encoding gradient along the through-plane (z) direction. All subjects were scanned and rescanned within 1 h. The Wilcoxon signed-rank test was used to test for differences between white matter and gray matter shear-stiffness values. One-way analysis of variance (ANOVA) was used to test for differences between shear-stiffness measurements made at different frequencies. Scan-rescan reproducibility was evaluated by calculating the within-subject coefficient of variation (CV) for each subject. The finite-element simulation showed that a pillow-like passive driver is capable of efficient shear-wave propagation through brain tissue. No subjects complained about discomfort during MRE acquisitions using the ergonomically designed driver. The white-matter elastic modulus (mean ± standard deviation) across all subjects was 3.85 ± 0.12 kPa, 3.78 ± 0.15 kPa, and 3.36 ± 0.11 kPa at frequencies of 60, 50, and 40 Hz, respectively. The gray-matter elastic modulus across all subjects was 3.33 ± 0.14 kPa, 2.82 ± 0.16 kPa, and 2.24 ± 0.14 kPa at frequencies of 60, 50, and 40 Hz, respectively. The Wilcoxon signed-rank test confirmed that the shear stiffness was significantly higher in white matter than gray matter at all three frequencies. The ranges of within-subject coefficients of variation for white matter, gray matter, and whole-brain shear-stiffness measurements for the three frequencies were 1.8-3.5% (60 Hz), 4.7-6.0% (50 Hz), and 3.7-4.1% (40 Hz). An ergonomic pneumatic pillow-like driver is feasible for highly reproducible in vivo evaluation of brain-tissue shear stiffness. Brain-tissue shear-stiffness values were frequency-dependent, thus emphasizing the importance of standardizing MRE acquisition protocols in multi-center studies.
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Affiliation(s)
- Xunan Huang
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Hatim Chafi
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Kenneth L Matthews
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Owen Carmichael
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | - Tanping Li
- School of Physics and Optoelectronic Engineering, Xidian University, Xi'an, Shaanxi 710071, China
| | - Qiguang Miao
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Shuzhen Wang
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China.
| | - Guang Jia
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China.
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New and Emerging Applications of Magnetic Resonance Elastography of Other Abdominal Organs. Top Magn Reson Imaging 2019; 27:335-352. [PMID: 30289829 DOI: 10.1097/rmr.0000000000000182] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increasing clinical experience and ongoing research in the field of magnetic resonance elastography (MRE) is leading to exploration of its applications in other abdominal organs. In this review, the current research progress of MRE in prostate, uterus, pancreas, spleen, and kidney will be discussed. The article will describe patient preparation, modified technical approach including development of passive drivers, modification of sequences, and inversion. The potential clinical application of MRE in the evaluation of several disease processes affecting these organs will be discussed. In an era of increasing adoption of multiparametric magnetic resonance imaging approaches for solving complex abdominal problems, abdominal MRE as a biomarker may be seamlessly incorporated into a standard magnetic resonance imaging examination to provide a rapid, reliable, and comprehensive imaging evaluation at a single patient appointment in the future.
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Kasson M, Ortman M, Gaitonde K, Verma S, Sidana A. Imaging Prostate Cancer Using Multiparametric Magnetic Resonance Imaging: Past, Present, and Future. Semin Roentgenol 2018; 53:200-205. [DOI: 10.1053/j.ro.2018.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Hammer SJ, Good DW, Scanlan P, Palacio-Torralba J, Phipps S, Stewart GD, Shu W, Chen Y, McNeill SA, Reuben RL. Quantitative mechanical assessment of the whole prostate gland ex vivo using dynamic instrumented palpation. Proc Inst Mech Eng H 2017; 231:1081-1100. [PMID: 28965486 DOI: 10.1177/0954411917734257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
An instrumented palpation sensor, designed for measuring the dynamic modulus of tissue in vivo, has been developed and trialled on ex vivo whole prostate glands. The sensor consists of a flexible membrane sensor/actuator with an embedded strain gauge and is actuated using a dynamically varying airflow at frequencies of 1 and 5 Hz. The device was calibrated using an indentation stiffness measurement rig and gelatine samples with a range of static modulus similar to that reported in the literature for prostate tissue. The glands were removed from patients with diagnosed prostate cancer scheduled for radical prostatectomy, and the stiffness was measured within 30 min of surgical removal. Each prostate was later examined histologically in a column immediately below each indentation point and graded into one of the four groups; normal, benign prostatic hyperplasia, cancerous and mixed cancer and benign prostatic hyperplasia. In total, 11 prostates were assessed using multiple point probing, and the complex modulus at 1 and 5 Hz was calculated on a point-by-point basis. The device yielded values of quasi-static modulus of 15 ± 0.5 kPa and dynamic modulus of 20 ± 0.5 kPa for whole prostates, and a sensitivity of up to 80% with slightly lower specificity was achieved on diagnosis of prostate cancer using a combination of mechanical measures. This assessment did not take into account some obvious factors such as edge effects, overlap and clinical significance of the cancer, all of which would improve performance. The device, as currently configured, is immediately deployable in vivo. A number of improvements are also identified which could improve the sensitivity and specificity in future embodiments of the probe.
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Affiliation(s)
- Steven J Hammer
- 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Daniel W Good
- 2 Department of Urology, Western General Hospital, Edinburgh, UK
- 3 Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Paul Scanlan
- 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Javier Palacio-Torralba
- 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Simon Phipps
- 2 Department of Urology, Western General Hospital, Edinburgh, UK
- 3 Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Grant D Stewart
- 3 Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Will Shu
- 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Yuhang Chen
- 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - S Alan McNeill
- 2 Department of Urology, Western General Hospital, Edinburgh, UK
- 3 Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Robert L Reuben
- 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
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Liu L, Tian Z, Zhang Z, Fei B. Computer-aided Detection of Prostate Cancer with MRI: Technology and Applications. Acad Radiol 2016; 23:1024-46. [PMID: 27133005 PMCID: PMC5355004 DOI: 10.1016/j.acra.2016.03.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 03/18/2016] [Accepted: 03/21/2016] [Indexed: 01/10/2023]
Abstract
One in six men will develop prostate cancer in his lifetime. Early detection and accurate diagnosis of the disease can improve cancer survival and reduce treatment costs. Recently, imaging of prostate cancer has greatly advanced since the introduction of multiparametric magnetic resonance imaging (mp-MRI). Mp-MRI consists of T2-weighted sequences combined with functional sequences including dynamic contrast-enhanced MRI, diffusion-weighted MRI, and magnetic resonance spectroscopy imaging. Because of the big data and variations in imaging sequences, detection can be affected by multiple factors such as observer variability and visibility and complexity of the lesions. To improve quantitative assessment of the disease, various computer-aided detection systems have been designed to help radiologists in their clinical practice. This review paper presents an overview of literatures on computer-aided detection of prostate cancer with mp-MRI, which include the technology and its applications. The aim of the survey is threefold: an introduction for those new to the field, an overview for those working in the field, and a reference for those searching for literature on a specific application.
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Affiliation(s)
- Lizhi Liu
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, GA 30329; Center of Medical Imaging and Image-guided Therapy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou, 510060, China
| | - Zhiqiang Tian
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, GA 30329
| | - Zhenfeng Zhang
- Center of Medical Imaging and Image-guided Therapy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou, 510060, China
| | - Baowei Fei
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, GA 30329; Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, 1841 Clifton Road NE, Atlanta, Georgia 30329; Winship Cancer Institute of Emory University, 1841 Clifton Road NE, Atlanta, Georgia 30329.
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Low G, Kruse SA, Lomas DJ. General review of magnetic resonance elastography. World J Radiol 2016; 8:59-72. [PMID: 26834944 PMCID: PMC4731349 DOI: 10.4329/wjr.v8.i1.59] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/14/2015] [Accepted: 12/04/2015] [Indexed: 02/06/2023] Open
Abstract
Magnetic resonance elastography (MRE) is an innovative imaging technique for the non-invasive quantification of the biomechanical properties of soft tissues via the direct visualization of propagating shear waves in vivo using a modified phase-contrast magnetic resonance imaging (MRI) sequence. Fundamentally, MRE employs the same physical property that physicians utilize when performing manual palpation - that healthy and diseased tissues can be differentiated on the basis of widely differing mechanical stiffness. By performing “virtual palpation”, MRE is able to provide information that is beyond the capabilities of conventional morphologic imaging modalities. In an era of increasing adoption of multi-parametric imaging approaches for solving complex problems, MRE can be seamlessly incorporated into a standard MRI examination to provide a rapid, reliable and comprehensive imaging evaluation at a single patient appointment. Originally described by the Mayo Clinic in 1995, the technique represents the most accurate non-invasive method for the detection and staging of liver fibrosis and is currently performed in more than 100 centers worldwide. In this general review, the mechanical properties of soft tissues, principles of MRE, clinical applications of MRE in the liver and beyond, and limitations and future directions of this discipline -are discussed. Selected diagrams and images are provided for illustration.
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Pepin KM, Ehman RL, McGee KP. Magnetic resonance elastography (MRE) in cancer: Technique, analysis, and applications. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 90-91:32-48. [PMID: 26592944 PMCID: PMC4660259 DOI: 10.1016/j.pnmrs.2015.06.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 05/07/2023]
Abstract
Tissue mechanical properties are significantly altered with the development of cancer. Magnetic resonance elastography (MRE) is a noninvasive technique capable of quantifying tissue mechanical properties in vivo. This review describes the basic principles of MRE and introduces some of the many promising MRE methods that have been developed for the detection and characterization of cancer, evaluation of response to therapy, and investigation of the underlying mechanical mechanisms associated with malignancy.
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Ipek-Ugay S, Drießle T, Ledwig M, Guo J, Hirsch S, Sack I, Braun J. Tabletop magnetic resonance elastography for the measurement of viscoelastic parameters of small tissue samples. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 251:13-18. [PMID: 25554945 DOI: 10.1016/j.jmr.2014.11.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 06/04/2023]
Abstract
We demonstrate the feasibility of low-cost tabletop MR elastography (MRE) for quantifying the complex shear modulus G(∗) of small soft biological tissue samples as provided by pathologists. The MRE system was developed based on a tabletop MRI scanner equipped with a 0.5 T permanent magnet and a tissue sample holder mounted to a loudspeaker. A spin echo sequence was enhanced with motion-encoding gradients of 250 mT/m amplitude synchronized to acoustic vibration frequencies. Shear wave images suitable for elastography were acquired between vibration frequencies of 0.5 and 1 kHz in agarose, ultrasound gel, porcine liver, porcine skeletal muscle, and bovine heart with a spatial resolution of 234 μm pixel edge length. The measured frequency dependence of G(∗) agreed well with previous work based on high-field MR systems. The ratio between loss and storage moduli was highest in liver and ultrasound gel, followed by muscle tissue and agarose gel while ultrasound gel and liver showed similarly low storage moduli compared to the other samples. The shear wave to noise ratio is an important imaging criteria for MRE and was about 4.2 times lower for the preliminary setup of the 0.5 T tabletop system compared to a 7 T animal scanner. In the future, the new tabletop MRE system may serve as a low cost device for preclinical research on the correlation of viscoelastic parameters with histopathology of biological samples.
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Affiliation(s)
- Selcan Ipek-Ugay
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | | | - Jing Guo
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Sebastian Hirsch
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jürgen Braun
- Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Numano T, Mizuhara K, Hata J, Washio T, Homma K. A simple method for MR elastography: a gradient-echo type multi-echo sequence. Magn Reson Imaging 2015; 33:31-7. [DOI: 10.1016/j.mri.2014.10.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 08/27/2014] [Accepted: 10/05/2014] [Indexed: 12/20/2022]
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Sahebjavaher RS, Nir G, Honarvar M, Gagnon LO, Ischia J, Jones EC, Chang SD, Fazli L, Goldenberg SL, Rohling R, Kozlowski P, Sinkus R, Salcudean SE. MR elastography of prostate cancer: quantitative comparison with histopathology and repeatability of methods. NMR IN BIOMEDICINE 2015; 28:124-139. [PMID: 25395244 DOI: 10.1002/nbm.3218] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 08/27/2014] [Accepted: 08/27/2014] [Indexed: 06/04/2023]
Abstract
The purpose of this work was to assess trans-perineal prostate magnetic resonance elastography (MRE) for (1) repeatability in phantoms/volunteers and (2) diagnostic power as correlated with histopathology in prostate cancer patients. The three-dimensional (3D) displacement field was obtained using a fractionally encoded gradient echo sequence using a custom-made transducer. The repeatability of the method was assessed based on three repeat studies and by changing the driving frequency by 3% in studies on a phantom and six healthy volunteers. Subsequently, 11 patients were examined with MRE prior to radical prostatectomy. The areas under the receiver operating characteristic curves were calculated using a windowed voxel-to-voxel approach by comparing the 2D registered slides, masked with the Gleason score. For the repeatability study, the average intraclass correlation coefficient for elasticity images was 99% for repeat phantom studies, 98% for ±6 Hz phantom studies, 95% for volunteer repeat studies with 2 min acquisition time, 82% for ±2 Hz volunteer studies with 2 min acquisition time and 73% for repeat volunteer studies with 8 min acquisition time. For the patient study, the average elasticity was 8.2 ± 1.7 kPa in the prostate capsule, 7.5 ± 1.9 kPa in the peripheral zone (PZ), 9.7 ± 3.0 kPa in the central gland (CG) and 9.0 ± 3.4 kPa in the transition zone. In the patient study, cancerous tissue with Gleason score at least 3 + 3 was significantly (p < 0.05) different from normal tissue in 10 out of 11 cases with tumors in the PZ, and 6 out of 9 cases with tumors in the CG. However, the overall case-averaged area under the curve was 0.72 in the PZ and 0.67 in the CG. Cancerous tissue was not always stiffer than normal tissue. The inversion algorithm was sensitive to (i) vibration amplitude and displacement nodes and (ii) misalignment of the 3D wave field due to subject movement.
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Affiliation(s)
- Ramin S Sahebjavaher
- University of British Columbia, Electrical and Computer Engineering, Vancouver, BC, Canada
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Sahebjavaher RS, Frew S, Bylinskii A, ter Beek L, Garteiser P, Honarvar M, Sinkus R, Salcudean S. Prostate MR elastography with transperineal electromagnetic actuation and a fast fractionally encoded steady-state gradient echo sequence. NMR IN BIOMEDICINE 2014; 27:784-94. [PMID: 24764278 DOI: 10.1002/nbm.3118] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 03/14/2014] [Accepted: 03/18/2014] [Indexed: 05/16/2023]
Abstract
Our aim is to develop a clinically viable, fast-acquisition, prostate MR elastography (MRE) system with transperineal excitation. We developed a new actively shielded electromagnetic transducer, designed to enable quick deployment and positioning within the scanner. The shielding of the transducer was optimized using simulations. We also employed a new rapid pulse sequence that encodes the three-dimensional displacement field in the prostate gland using a fractionally encoded steady-state gradient echo sequence, thereby shortening the acquisition time to a clinically acceptable 8-10 min. The methods were tested in two phantoms and seven human subjects (six volunteers and one patient with prostate cancer). The MRE acquisition time for 24 slices, with an isotropic resolution of 2 mm and eight phase offsets, was 8 min, and the total scan, including positioning and set-up, was performed in 15-20 min. The phantom study demonstrated that the transducer does not interfere with the acquisition process and that it generates displacement amplitudes that exceed 100 µm even at frequencies as high as 300 Hz. In the in vivo human study, average wave amplitudes of 30 µm (46 µm at the apex) were routinely achieved within the prostate gland at 70 Hz. No pain or discomfort was reported. Results in a single patient suggest that MRE can identify cancer tumors, although this result is preliminary. The proposed methods allow the integration of prostate MRE with other multiparametric MRI methods. The results of this study clearly motivate the clinical evaluation of transperineal MRE in patients.
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Penzkofer T, Tempany-Afdhal CM. Prostate cancer detection and diagnosis: the role of MR and its comparison with other diagnostic modalities--a radiologist's perspective. NMR IN BIOMEDICINE 2014; 27:3-15. [PMID: 24000133 PMCID: PMC3851933 DOI: 10.1002/nbm.3002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 06/16/2013] [Accepted: 06/18/2013] [Indexed: 05/07/2023]
Abstract
It is now universally recognized that many prostate cancers are over-diagnosed and over-treated. The European Randomized Study of Screening for Prostate Cancer from 2009 evidenced that, to save one man from death from prostate cancer, over 1400 men need to be screened, and 48 need to undergo treatment. The detection of prostate cancer is traditionally based on digital rectal examination (DRE) and the measurement of serum prostate-specific antigen (PSA), followed by ultrasound-guided biopsy. The primary role of imaging for the detection and diagnosis of prostate cancer has been transrectal ultrasound (TRUS) guidance during biopsy. Traditionally, MRI has been used primarily for the staging of disease in men with biopsy-proven cancer. It has a well-established role in the detection of T3 disease, planning of radiation therapy, especially three-dimensional conformal or intensity-modulated external beam radiation therapy, and planning and guiding of interstitial seed implant or brachytherapy. New advances have now established that prostate MRI can accurately characterize focal lesions within the gland, an ability that has led to new opportunities for improved cancer detection and guidance for biopsy. Two new approaches to prostate biopsy are under investigation. Both use pre-biopsy MRI to define potential targets for sampling, and the biopsy is performed either with direct real-time MR guidance (in-bore) or MR fusion/registration with TRUS images (out-of-bore). In-bore and out-of-bore MRI-guided prostate biopsies have the advantage of using the MR target definition for the accurate localization and sampling of targets or suspicious lesions. The out-of-bore method uses combined MRI/TRUS with fusion software that provides target localization and increases the sampling accuracy of TRUS-guided biopsies by integrating prostate MRI information with TRUS. Newer parameters for each imaging modality, such as sonoelastography or shear wave elastography, contrast-enhanced ultrasound and MRI elastography, show promise to further enrich datasets.
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Affiliation(s)
- Tobias Penzkofer
- Division of MRI and Surgical Planning Laboratory, Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA; Department of Diagnostic and Interventional Radiology, Aachen University Hospital, RWTH Aachen University, Aachen, Germany
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Hegde JV, Mulkern RV, Panych LP, Fennessy FM, Fedorov A, Maier SE, Tempany CMC. Multiparametric MRI of prostate cancer: an update on state-of-the-art techniques and their performance in detecting and localizing prostate cancer. J Magn Reson Imaging 2013; 37:1035-54. [PMID: 23606141 DOI: 10.1002/jmri.23860] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 09/04/2012] [Indexed: 12/15/2022] Open
Abstract
Magnetic resonance (MR) examinations of men with prostate cancer are most commonly performed for detecting, characterizing, and staging the extent of disease to best determine diagnostic or treatment strategies, which range from biopsy guidance to active surveillance to radical prostatectomy. Given both the exam's importance to individual treatment plans and the time constraints present for its operation at most institutions, it is essential to perform the study effectively and efficiently. This article reviews the most commonly employed modern techniques for prostate cancer MR examinations, exploring the relevant signal characteristics from the different methods discussed and relating them to intrinsic prostate tissue properties. Also, a review of recent articles using these methods to enhance clinical interpretation and assess clinical performance is provided. J. Magn. Reson. Imaging 2013;37:1035-1054. © 2013 Wiley Periodicals, Inc.
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Affiliation(s)
- John V Hegde
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Numano T, Kawabata Y, Mizuhara K, Washio T, Nitta N, Homma K. Magnetic resonance elastography using an air ball-actuator. Magn Reson Imaging 2013; 31:939-46. [DOI: 10.1016/j.mri.2013.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 01/23/2013] [Accepted: 02/20/2013] [Indexed: 11/26/2022]
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Powell DK, Kodsi KL, Levin G, Yim A, Nicholson D, Kagen AC. Comparison of comfort and image quality with two endorectal coils in MRI of the prostate. J Magn Reson Imaging 2013; 39:419-26. [DOI: 10.1002/jmri.24179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 03/27/2013] [Indexed: 11/10/2022] Open
Affiliation(s)
- Daniel K. Powell
- Department of Radiology; Beth Israel Medical Center; New York New York USA
| | - Karen L. Kodsi
- Department of Radiology; Beth Israel Medical Center; New York New York USA
- Department of Radiology; St. Luke's-Roosevelt Hospital; New York New York USA
| | - Galina Levin
- Department of Radiology; Beth Israel Medical Center; New York New York USA
- Department of Radiology; St. Luke's-Roosevelt Hospital; New York New York USA
| | - Angela Yim
- Department of Radiology; Beth Israel Medical Center; New York New York USA
- Department of Radiology; St. Luke's-Roosevelt Hospital; New York New York USA
| | - Duane Nicholson
- Department of Radiology; Beth Israel Medical Center; New York New York USA
| | - Alexander C. Kagen
- Department of Radiology; Beth Israel Medical Center; New York New York USA
- Department of Radiology; St. Luke's-Roosevelt Hospital; New York New York USA
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Arani A, Da Rosa M, Ramsay E, Plewes DB, Haider MA, Chopra R. Incorporating endorectal MR elastography into multi-parametric MRI for prostate cancer imaging: Initial feasibility in volunteers. J Magn Reson Imaging 2013; 38:1251-60. [PMID: 23408516 DOI: 10.1002/jmri.24028] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 12/12/2012] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To investigate the tolerability and technical feasibility of performing endorectal MR elastography (eMRE) in human volunteers within the representative age group commonly affected by prostate cancer. MATERIALS AND METHODS Endorectal MRE was conducted on seven volunteers in a 1.5 Tesla (T) MR imager using a rigid endorectal coil. Another five volunteers were imaged on a 3T MR imager using an inflatable balloon type endorectal coil. Tolerability was accessed for vibration amplitudes of ±1-50 μm and for frequencies of 100-300 Hz. RESULTS All 12 volunteers tolerated the displacements necessary to successfully perform eMRE. Shear waves with frequencies up to 300 Hz could propagate across the entire prostate using both coil designs. CONCLUSION The results of this study motivate further investigation of eMRE in prostate cancer patients to help determine if there is an added value of integrating eMRE into existing multi-parametric prostate MRI exams.
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Affiliation(s)
- Arvin Arani
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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Godfrey EM, Mannelli L, Griffin N, Lomas DJ. Magnetic resonance elastography in the diagnosis of hepatic fibrosis. Semin Ultrasound CT MR 2013; 34:81-88. [PMID: 23395320 DOI: 10.1053/j.sult.2012.11.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Liver fibrosis is a common feature of many chronic liver diseases, and can ultimately progress to cirrhosis. Conventional imaging is insensitive to liver fibrosis, necessitating a liver biopsy for diagnosis and monitoring of progression. However, liver biopsy risks complications, and is an imperfect gold standard in view of sampling error and intraobserver or interobserver variation. Magnetic resonance elastography (MRE) is a noninvasive method for assessing the mechanical properties of tissues and is gaining credence as a method of assessment for hepatic fibrosis. The aim of this review is to describe how MRE is performed, to review the present literature on the subject, to compare MRE with other noninvasive techniques used to assess for liver fibrosis, and to highlight areas of future research.
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Affiliation(s)
- Edmund M Godfrey
- Department of Radiology, Leeds Teaching Hospitals NHS Trust, UK.
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Thörmer G, Reiss-Zimmermann M, Otto J, Hoffmann KT, Moche M, Garnov N, Kahn T, Busse H. Novel technique for MR elastography of the prostate using a modified standard endorectal coil as actuator. J Magn Reson Imaging 2012; 37:1480-5. [PMID: 23055397 DOI: 10.1002/jmri.23850] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 08/30/2012] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To present a novel method for MR elastography (MRE) of the prostate at 3 Tesla using a modified endorectal imaging coil. MATERIALS AND METHODS A commercial endorectal coil was modified to dynamically generate mechanical stress (contraction and dilation) in a prostate phantom with embedded phantom "lesions" (6 mm diameter) and in a porcine model. Resulting tissue displacements were measured with a motion-sensitive EPI sequence at actuation frequencies of 50-200 Hz. Maps of shear modulus G were calculated from the measured phase-difference shear-wave patterns. RESULTS In the G maps of the phantom, "lesions" were easily discernible against the background. The average G values of regions of interest placed in the "lesion" (8.2 ± 1.9 kPa) were much higher than those in the background (3.6 ± 1.4 kPa) but systematically lower than values reported by the vendor (13.0 ± 1.0 and 6.7 ± 0.7 kPa, respectively). In the porcine model, shear waves could be generated and measured shear moduli were substantially different for muscle (7.1 ± 2.0 kPa), prostate (3.0 ± 1.4 kPa), and bulbourethral gland (5.6 ± 1.9 kPa). CONCLUSION An endorectal MRE concept is technically feasible. The presented technique will allow for simultaneous MRE and MRI acquisitions using a commercial base device with minor, MR-conditional modifications. The diagnostic value needs to be determined in further trials.
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Affiliation(s)
- Gregor Thörmer
- Department of Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany
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Lee CU, Glockner JF, Glaser KJ, Yin M, Chen J, Kawashima A, Kim B, Kremers WK, Ehman RL, Gloor JM. MR elastography in renal transplant patients and correlation with renal allograft biopsy: a feasibility study. Acad Radiol 2012; 19:834-41. [PMID: 22503893 DOI: 10.1016/j.acra.2012.03.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 03/03/2012] [Accepted: 03/04/2012] [Indexed: 12/22/2022]
Abstract
RATIONALE AND OBJECTIVES Magnetic resonance elastography (MRE) images the propagation of mechanical shear waves in tissue and uses that information to generate quantitative measures of tissue stiffness. Hepatic MRE has been successfully performed in thousands of patients, with good correlation between histologic grade of fibrosis and tissue stiffness. There has been no prior investigation of the utility of MRE for the assessment of kidney transplants. The aims of this study were to prospectively evaluate the feasibility of MRE in a small group of kidney transplant recipients and to correlate the measured magnetic resonance elastographic stiffness values with biopsy-proven histopathologic fibrosis. MATERIALS AND METHODS MRE of renal transplants was performed in 11 patients returning for protocol allograft biopsies. Calculated tissue stiffness values were compared to histologic degree of fibrosis in nine of the 11 patients. RESULTS The mean stiffness of two patients with moderate interstitial fibrosis was higher than the mean of six patients with mild interstitial fibrosis, but not significantly so (90 Hz, P = .12; 120 Hz, P = .17; 150 Hz, P = .26). The mean stiffness of the two patients with moderate interstitial fibrosis was slightly greater than the mean of one patient with no significant interstitial fibrosis at 90 Hz (P = .78) and slightly less at 120 and 150 Hz (P = .88 and P = .76). The mean stiffness of the six patients with mild interstitial fibrosis did not differ significantly from that of the one patient with no interstitial fibrosis (90 Hz, P = .35; 120 Hz, P = .22; 150 Hz, P = .16). CONCLUSIONS Preliminary results demonstrate feasibility and support known multifactorial influences on renal stiffness.
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Sahebjavaher RS, Baghani A, Honarvar M, Sinkus R, Salcudean SE. Transperineal prostate MR elastography: initial in vivo results. Magn Reson Med 2012; 69:411-20. [PMID: 22505273 DOI: 10.1002/mrm.24268] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 02/29/2012] [Accepted: 03/01/2012] [Indexed: 12/30/2022]
Abstract
This article presents a new approach to magnetic resonance elastography of the prostate using transperineal mechanical excitation. This approach is validated using a prostate elasticity phantom and in vivo studies of healthy volunteers. It is demonstrated that the transperineal approach can generate shear wave amplitudes on the order of 6-30 μm in the mid-gland region. The driver was implemented using an electromagnetic actuator with a hydraulic transmission system. The magnetic resonance elastography acquisition time has been reduced significantly by using a "second harmonic" approach. Displacement fields are processed using the established three-dimensional local frequency estimation algorithm. The three-dimensional curl-based direct inversion was used to calculate the local wavelength. The traveling wave expansion algorithm was used to reconstruct the wave damping image for one case. Using the proposed method, it was possible to resolve lesions of 0.5 cc in the phantom study. Repeatability experiments were performed and analyzed. The results from this study indicate that transperineal magnetic resonance elastography--without an endorectal coil--is a suitable candidate for a patient study involving multiparametric magnetic resonance imaging of prostate cancer, where magnetic resonance elastography may provide additional information for improved diagnosis and image-based surveillance.
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Affiliation(s)
- Ramin S Sahebjavaher
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
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