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Wong OL, Yuan J, Poon DMC, Chiu ST, Yang B, Chiu G, Yu SK, Cheung KY. Prostate diffusion-weighted imaging (DWI) in MR-guided radiotherapy: Reproducibility assessment on 1.5 T MR-Linac and 1.5 T MR-simulator. Magn Reson Imaging 2024; 111:47-56. [PMID: 38513789 DOI: 10.1016/j.mri.2024.03.020] [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: 01/11/2024] [Revised: 03/11/2024] [Accepted: 03/16/2024] [Indexed: 03/23/2024]
Abstract
PURPOSE Diffusion-weighted imaging (DWI) holds promise for image-guided radiotherapy (MRgRT) in prostate cancer. However, challenges persist due to image distortion, artifacts, and apparent diffusion coefficient (ADC) reproducibility issues. This study aimed to assess DWI image quality and ADC reproducibility on both a 1.5 T MR-simulator and a 1.5 T MR-Linac, employing measurements from both an ACR MRI phantom and prostate cancer patients undergoing MRgRT. METHODS DW-MRI scans were conducted on 19 patients (mean age = 69 ± 8 years, with 23 MR-visible intra-prostatic lesions) and an ACR MRI phantom using a 1.5 T MR-simulator (b-values = 0, 800, 1400s/mm2) and a 1.5 T MR-Linac (b-values = 50, 500, 800 s/mm2). ADC homogeneity in the phantom was evaluated via 1D profile flatness (FL) in three directions. Image quality was assessed through qualitative 5-point Likert scale ratings and quantitative ADC and signal-to-noise ratio (SNR) measurements. Intra-observer reproducibility of image quality scores was evaluated using ICC(1, 2). Geometric distortion was measured by comparing landmark sizes on the ACR phantom against the ground truth. Mean ADC and reproducibility were assessed using Bland-Altman plots. RESULTS Both MR-simulator and MR-Linac demonstrated high ADC homogeneity (FL > 87.5% - MR-simulator: 97.23 ± 0.62%, MR-Linac: 94.75 ± 0.62%, p < 0.05) in the phantom. Image quality scores revealed acceptable ratings (≥3) for capsule demarcation, image artifacts, and geometric distortion in patients. However, intra-prostatic lesions were barely discernible in b800 images for both MR-simulator (average score = 2.37 ± 1.33) and MR-Linac (average score = 2.16 ± 1.28). While MR-Linac DWI scans exhibited significantly more severe geometric distortion than MR-simulator scans (p < 0.01), most phantom measurements fell within the image in-plane resolution of 3 mm. Significant differences were noted in MR-simulator ADC (CTV: 1.20 ± 0.14 × 10-3 mm2/s (MR-simulator) vs 1.06 ± 0.10 × 10-3 mm2/s (MR-Linac); GTV: 1.05 ± 0.21 × 10-3 mm2/s vs 0.91 ± 0.16 × 10 mm2/s, all p < 0.05), with a small non-zero bias observed in the Bland-Altman analysis (CTV: 12.3%; GTV: 14.5%). CONCLUSION The significantly larger MR-simulator ADC and the small non-zero bias hint at potential systematic differences in ADC values acquired from an MR-simulator and an MR-Linac, both at 1.5 T. Although acceptable ADC homogeneity was noted, caution is warranted in interpreting MR-Linac DWI images due to occasional severe artifacts. Further studies are essential to validate DWI and ADC as reliable imaging markers in prostate cancer MRgRT.
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Affiliation(s)
- Oi Lei Wong
- Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China.
| | - Jing Yuan
- Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
| | - Darren M C Poon
- Comprehensive Oncology Center, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
| | - Sin Ting Chiu
- Department of Radiotherapy, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
| | - Bin Yang
- Medical Physics Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
| | - George Chiu
- Department of Radiotherapy, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
| | - Siu Ki Yu
- Medical Physics Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
| | - Kin Yin Cheung
- Medical Physics Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR, China
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Altmann S, Grauhan NF, Mercado MAA, Steinmetz S, Kronfeld A, Paul R, Benkert T, Uphaus T, Groppa S, Winter Y, Brockmann MA, Othman AE. Deep Learning Accelerated Brain Diffusion-Weighted MRI with Super Resolution Processing. Acad Radiol 2024:S1076-6332(24)00139-9. [PMID: 38521612 DOI: 10.1016/j.acra.2024.02.049] [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: 12/31/2023] [Revised: 02/20/2024] [Accepted: 02/26/2024] [Indexed: 03/25/2024]
Abstract
OBJECTIVES To investigate the clinical feasibility and image quality of accelerated brain diffusion-weighted imaging (DWI) with deep learning image reconstruction and super resolution. METHODS 85 consecutive patients with clinically indicated MRI at a 3 T scanner were prospectively included. Conventional diffusion-weighted data (c-DWI) with four averages were obtained. Reconstructions of one and two averages, as well as deep learning diffusion-weighted imaging (DL-DWI), were accomplished. Three experienced readers evaluated the acquired data using a 5-point Likert scale regarding overall image quality, overall contrast, diagnostic confidence, occurrence of artefacts and evaluation of the central region, basal ganglia, brainstem, and cerebellum. To assess interrater agreement, Fleiss' kappa (ϰ) was determined. Signal intensity (SI) levels for basal ganglia and the central region were estimated via automated segmentation, and SI values of detected pathologies were measured. RESULTS Intracranial pathologies were identified in 35 patients. DL-DWI was significantly superior for all defined parameters, independently from applied averages (p-value <0.001). Optimum image quality was achieved with DL-DWI by utilizing a single average (p-value <0.001), demonstrating very good (80.9%) to excellent image quality (14.5%) in nearly all cases, compared to 12.5% with very good and 0% with excellent image quality for c-MRI (p-value <0.001). Comparable results could be shown for diagnostic confidence. Inter-rater Fleiss' Kappa demonstrated moderate to substantial agreement for virtually all defined parameters, with good accordance, particularly for the assessment of pathologies (p = 0.74). Regarding SI values, no significant difference was found. CONCLUSION Ultra-fast diffusion-weighted imaging with super resolution is feasible, resulting in highly accelerated brain imaging while increasing diagnostic image quality.
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Affiliation(s)
- Sebastian Altmann
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Nils F Grauhan
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Mario Alberto Abello Mercado
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Sebastian Steinmetz
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Andrea Kronfeld
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Roman Paul
- Institute of Medical Biostatistics, Epidemiology and Informatics (IMBEI), University Medical Center Mainz, Johannes Gutenberg University, Rhabanusstr. 3/Tower A, 55118 Mainz, Germany
| | | | - Timo Uphaus
- Department of Neurology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Sergiu Groppa
- Department of Neurology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Yaroslav Winter
- Department of Neurology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany; Department of Neurology, Philipps-University Marburg, Baldingerstr, 35043 Marburg, Germany
| | - Marc A Brockmann
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Ahmed E Othman
- Department of Neuroradiology, University Medical Center Mainz, Johannes Gutenberg University, Langenbeckstr. 1, 55131 Mainz, Germany
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El Khababi N, Beets-Tan RGH, Tissier R, Lahaye MJ, Maas M, Curvo-Semedo L, Dresen RC, Nougaret S, Beets GL, Lambregts DMJ. Comparison of MRI response evaluation methods in rectal cancer: a multicentre and multireader validation study. Eur Radiol 2022; 33:4367-4377. [PMID: 36576549 DOI: 10.1007/s00330-022-09342-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/30/2022] [Accepted: 11/29/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To compare four previously published methods for rectal tumor response evaluation after chemoradiotherapy on MRI. METHODS Twenty-two radiologists (5 rectal MRI experts, 17 general/abdominal radiologists) retrospectively reviewed the post-chemoradiotherapy MRIs of 90 patients, scanned at 10 centers (with non-standardized protocols). They applied four response methods; two based on T2W-MRI only (MRI tumor regression grade (mrTRG); split-scar sign), and two based on T2W-MRI+DWI (modified-mrTRG; DWI-patterns). Image quality was graded using a 0-6-point score (including slice thickness and in-plane resolution; sequence angulation; DWI b-values, signal-to-noise, and artefacts); scores < 4 were classified below average. Mixed model linear regression was used to calculate average sensitivity/specificity/accuracy to predict a complete response (versus residual tumor) and assess the impact of reader experience and image quality. Group interobserver agreement (IOA) was calculated using Krippendorff's alpha. Readers were asked to indicate their preferred scoring method(s). RESULTS Average sensitivity/specificity/accuracy was 57%/64%/62% (mrTRG), 36%/79%/66% (split-scar), 40%/79%/67% (modified-mrTRG), and 37%/82%/68% (DWI-patterns); mrTRG showed higher sensitivity but lower specificity and accuracy (p < 0.001) compared to the other methods. IOA was lower for the split scar method (0.18 vs. 0.39-0.43). Higher reader experience had a significant positive effect on diagnostic performance and IOA (except for the split scar sign); below-average imaging quality had a significant negative effect on diagnostic performance. DWI pattern was selected as the preferred method by 73% of readers. CONCLUSIONS Methods incorporating DWI showed the most favorable results when combining diagnostic performance, IOA, and reader preference. Reader experience and image quality clearly impacted diagnostic performance emphasizing the need for state-of-the-art imaging and dedicated radiologist training. KEY POINTS • In a multireader study comparing 4 MRI methods for rectal tumor response evaluation, those incorporating DWI showed the best results when combining diagnostic performance, IOA, and reader preference. • The most preferred method (by 73% of readers) was the "DWI patterns" approach with an accuracy of 68%, high specificity of 82%, and group IOA of 0.43. • Reader experience level and MRI quality had an evident effect on diagnostic performance and IOA.
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Affiliation(s)
- Najim El Khababi
- Department of Radiology, The Netherlands Cancer Institute, P.O. Box 90203, 1106, BE, Amsterdam, The Netherlands.,GROW School for Oncology & Developmental Biology, University of Maastricht, Maastricht, The Netherlands
| | - Regina G H Beets-Tan
- Department of Radiology, The Netherlands Cancer Institute, P.O. Box 90203, 1106, BE, Amsterdam, The Netherlands.,GROW School for Oncology & Developmental Biology, University of Maastricht, Maastricht, The Netherlands
| | - Renaud Tissier
- Department of Epidemiology and Biostatistics, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Max J Lahaye
- Department of Radiology, The Netherlands Cancer Institute, P.O. Box 90203, 1106, BE, Amsterdam, The Netherlands.,GROW School for Oncology & Developmental Biology, University of Maastricht, Maastricht, The Netherlands
| | - Monique Maas
- Department of Radiology, The Netherlands Cancer Institute, P.O. Box 90203, 1106, BE, Amsterdam, The Netherlands.,GROW School for Oncology & Developmental Biology, University of Maastricht, Maastricht, The Netherlands
| | - Luís Curvo-Semedo
- Department of Radiology, Centro Hospitalar e Universitario de Coimbra EPE, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Raphaëla C Dresen
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Stephanie Nougaret
- Medical Imaging Department, Montpellier Cancer Institute, Montpellier Cancer Research Institute (U1194), University of Montpellier, Montpellier, France
| | - Geerard L Beets
- GROW School for Oncology & Developmental Biology, University of Maastricht, Maastricht, The Netherlands.,Department of Surgery, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Doenja M J Lambregts
- Department of Radiology, The Netherlands Cancer Institute, P.O. Box 90203, 1106, BE, Amsterdam, The Netherlands. .,GROW School for Oncology & Developmental Biology, University of Maastricht, Maastricht, The Netherlands.
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Hosseiny M, Sung KH, Felker E, Suvannarerg V, Tubtawee T, Shafa A, Arora KR, Ching J, Gulati A, Azadikhah A, Zhong X, Sayre J, Lu D, Raman SS. Read-out Segmented Echo Planar Imaging with Two-Dimensional Navigator Correction (RESOLVE): An Alternative Sequence to Improve Image Quality on Diffusion-Weighted Imaging of Prostate. Br J Radiol 2022; 95:20211165. [PMID: 35671135 PMCID: PMC10162059 DOI: 10.1259/bjr.20211165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 04/28/2022] [Accepted: 05/23/2022] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE We aimed to investigate if the use of read-out segmented echoplanar imaging with additional two-dimensional navigator correction (Readout Segmentation of Long Variable Echo, RESOLVE) for acquiring prostate diffusion-weighted imaging (DWI) improves image quality, compared to single-shot echoplanar imaging (ss-EPI). METHODS This single-center prospective study cohort included 162 males with suspected prostate cancer, who underwent 3 Tesla multiparametric MRI (3T-mpMRI). Two abdominal radiologists, blinded to the clinical information, separately reviewed each 3T-mpMRI study to rank geometrical distortion, degree of rectal distention, lesion conspicuity, and anatomic details delineation first on ss-EPI-DWI and later on RESOLVE-DWI using 5-point scales (1 = excellent, 5 = poor). The average of the ranking scores given by two readers was generated and used as the final score. RESULTS There was good-to-excellent interreader agreement for scoring image quality parameters on both ss-EPI and RESOLVE. Geometrical distortion scores > 3 was seen in 12.3% (20/162) of ss-EPI images, with all having geometrical distortion score <3 on RESOLVE (p < .001). The mean image distortion score was significantly less on RESOLVE than ss-EPI (1.16 vs 1.61, p < .01 regardless of rectal gas, p< .05 when stratified by the degree of rectal distention ). RESOLVE was superior to ss-EPI for lesion conspicuity (mean 1.35 vs 1.53, p< .002) and anatomic delineation (2.60 vs 2.68, p< .001) of prostate on DWI. CONCLUSION Compared to conventional ss-EPI, the use of RESOLVE for acquisition of prostate DWI resulted in significantly enhanced image quality and reduced geometrical distortion. ADVANCES IN KNOWLEDGE RESOLVE could be an alternative or replacement of ss-EPI for acquiring prostate DWI with significantly less geometrical distortion and significantly improved lesion conspicuity and anatomic delineation.
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Affiliation(s)
- Melina Hosseiny
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Kyung Hyun Sung
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Ely Felker
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Voraparee Suvannarerg
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | | | - Ariel Shafa
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Krishan R. Arora
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Justin Ching
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Anjalie Gulati
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Afshin Azadikhah
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Xiaodong Zhong
- Siemens Healthcare, MR R&D Collaborations, Lilburn, Georgia, United States
| | - James Sayre
- Department of Bioinformatics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - David Lu
- Department of Radiology, Ronald Reagan-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
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Chen Y, Pan Z, Meng F, Xu Q, Huang L, Pu X, Yu X, Wu Y, Lyu H, Lin X. Assessment of Rat Sciatic Nerve Using Diffusion-Tensor Imaging With Readout-Segmented Echo Planar Imaging. Front Neurosci 2022; 16:938674. [PMID: 35812234 PMCID: PMC9260505 DOI: 10.3389/fnins.2022.938674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectivesThis study aimed to compare readout-segmented-3, readout-segmented-5, and readout-segmented-7 echo-planar imaging (RS3-EPI, RS5-EPI, and RS7-EPI) of DTI in the assessment of rat sciatic nerve at 3T MR.MethodsEight male adult healthy Sprague-Dawley rats were scanned at 3T MR with RS-3 EPI, RS5-EPI, and RS-7 EPI DTI. The image quality of RS-3 EPI, RS-5 EPI, and RS-7 EPI in terms of the nerve morphology, distortions of the nearby femur, muscles, and homogeneity of neuromuscular were evaluated by two experienced radiologists. The correlations between the histopathological and DTI parameters, including fractional anisotropy (FA) and radial diffusivity (RD), were calculated, respectively, and compared in RS-3, RS-5, and RS-7 EPI. The image quality scores for RS-3 EPI, RS-5 EPI, and RS-7 EPI were compared using the Wilcoxon rank-sum test. The correlation between DTI and histopathological parameters was calculated using the Pearson correlation coefficient.ResultsRS-5 EPI yielded the best SNR-values corrected for the acquisition time compared to RS3-EPI and RS7-EPI. The image quality scores of RS-5 EPI were superior to those of RS-3 and RS-7 EPI (P = 0.01–0.014) and lower artifacts of the ventral/dorsal margin and femur (P = 0.008–0.016) were shown. DTT analysis yielded a significantly higher number of tracts for RS5-EPI compared to RS3-EPI (P = 0.007) but no significant difference with RS7-EPI (P = 0.071). For the three sequences, FA and RD were well-correlated with the myelin-related histopathological parameters (|r| 0.709–0.965, P = 0.001–0.049). The overall correlation coefficients of FA and RD obtained from RS-5 EPI were numerically higher than that with both RS3-EPI and RS7-EPI.ConclusionFor the rat sciatic nerve DTI imaging, RS-5 EPI offered the best image quality and SNR-values corrected for the acquisition time. The FA and RD derived from the RS-5 EPI were the most sensitive quantitative biomarkers to detect rat sciatic nerve histopathological change.
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Affiliation(s)
- Yueyao Chen
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Zhongxian Pan
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Fanqi Meng
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Qian Xu
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Leyu Huang
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Xuejia Pu
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Xuewen Yu
- Department of Pathology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | | | - Hanqing Lyu
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
- *Correspondence: Hanqing Lyu,
| | - Xiaofeng Lin
- Department of Nuclear Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
- Xiaofeng Lin,
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Chen Y, Pan Z, Meng F, Li Z, Hu Y, Yu X, Gao J, Guo Y, Lyu H, Lin X. Performance of Single-Shot Echo-Planar Imaging in Diffusion Tensor Imaging in Rat Sciatic Nerve Compared With Readout-Segmented Echo-Planar Imaging. Front Neurosci 2022; 16:844408. [PMID: 35645709 PMCID: PMC9133884 DOI: 10.3389/fnins.2022.844408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Objectives To compare the performances of single-shot echo-planar imaging (SS–EPI) and readout-segmented echo-planar imaging (RS–EPI) for diffusion tensor imaging (DTI) of the rat sciatic nerve. Methods Eight healthy adult male Sprague-Dawley rats were anesthetized and scanned with a 3T MRI scanner using SS–EPI and RS–EPI DTI sequences. The image quality in terms of the morphology of the nerve, distortions of the nearby femur, muscles, and homogeneity of neuromuscular were evaluated and scored. The correlations between the DTI parameters including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), apparent diffusion coefficient (ADC), and histopathological parameters were calculated by using the Pearson correlation coefficient and compared by the modified Fisher Z-transform, respectively. Results The quality scores were higher for the images from the SS–EPI sequence compared with the RS–EPI sequence for characteristics such as sharpness of the sciatic nerve margin (P = 0.008), artifacts of the sciatic nerve (P = 0.008), and homogeneity of the neuromuscular region (P = 0.007), as well as the contrast-to-noise ratio (CNR) of DW images (P < 0.001). The correlation coefficients were higher for the FA and RD values from the SS–EPI sequence compared with those from the RS–EPI sequence. Furthermore, the correlation coefficients between FA and myelin thickness (P = 0.027), FA and diameter of the myelinated fiber (P = 0.036), as well as RD and myelin thickness (P = 0.05) were statistically higher for the SS–EPI sequence compared with those for the RS–EPI sequence. Conclusion Diffusion tensor imaging analysis of the rat sciatic nerve showed that the image quality from the SS–EPI sequence was significantly higher compared with that from the RS–EPI sequence. Furthermore, the FA and RD derived from the SS–EPI sequence are promising and sensitive biomarkers to detect the histopathological changes in the rat sciatic nerve.
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Affiliation(s)
- Yueyao Chen
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Zhongxian Pan
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Fanqi Meng
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Zhujing Li
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Yuanming Hu
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Xuewen Yu
- Department of Pathology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Jinyun Gao
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Yihao Guo
- Magnetic Resonance Collaboration, Siemens Healthcare, Guangzhou, China
| | - Hanqing Lyu
- Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine, Shenzhen, China
- *Correspondence: Hanqing Lyu,
| | - Xiaofeng Lin
- Department of Nuclear Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
- Xiaofeng Lin,
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Song R, Glass JO, Reddick WE. Modified Diffusion Tensor Image Processing Pipeline for Archived Studies of Patients With Leukoencephalopathy. J Magn Reson Imaging 2021; 54:997-1008. [PMID: 33856092 DOI: 10.1002/jmri.27636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND In archived diffusion tensor imaging (DTI) studies, a reversed-phase encoding (PE) scan required to correct the distortion in single-shot echo-planar imaging (EPI) may not have been acquired. Furthermore, DTI tractography is adversely affected by incorrect white matter segmentation due to leukoencephalopathy (LE). All these issues need to be addressed. PURPOSE To propose and evaluate a modified DTI processing pipeline with DIstortion COrrection using pseudo T2 -weighted images (DICOT) to overcome limitations in existing acquisition protocols. STUDY TYPE Retrospective feasibility. SUBJECTS DICOT was assessed in simulated data and 84 acute lymphoblastic leukemia (ALL) patients with reversed PE acquired. The pipeline was then tested in 522 scans from 261 ALL patients without a reversed PE acquired. FIELD STRENGTH/SEQUENCE A 3 T; diffusion-weighted EPI; 3D magnetization prepared rapid acquisition gradient echo (MPRAGE). STATISTICAL TESTS Repeated measures analysis of variance and Tukey post hoc tests were performed to compare fractional anisotropy (FA) values obtained by different methods. ASSESSMENT FA and corresponding absolute error maps were obtained using TOPUP, DICOT, INVERSION (Inverse contrast Normalization for VERy Simple registratION) and NO CORR (no correction). Each method was assessed by comparing to TOPUP. The pipeline in the ALL patients was evaluated based on the failure rate of the distortion correction using the global correlation values. RESULTS Using DICOT reduced the mean absolute errors by an average of 32% in FA in simulation datasets. In 84 patients, the error reductions were approximately 15% in FA with DICOT, while it was 5% with INVERSION. No significant differences between the TOPUP and DICOT were observed in FA with P = 0.090/0.894(AP/PA). Only 15 of 516 examinations requiring any additional manual intervention. CONCLUSION This modified pipeline produced better results than the INVERSION. Furthermore, robust performance was demonstrated in archived patient scans acquired without an inverse PE necessary for TOPUP correction. EVIDENCE LEVEL 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Ruitian Song
- Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - John O Glass
- Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Wilburn E Reddick
- Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, Tennessee, USA
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Comparison of Field-of-view Optimized and Constrained Undistorted Single Shot With Conventional Intravoxel Incoherent Motion Diffusion-Weighted Imaging for Measurements of Diffusion and Perfusion in Vertebral Bone Marrow. J Comput Assist Tomogr 2021; 45:98-102. [PMID: 33186175 DOI: 10.1097/rct.0000000000001111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND PURPOSE A limited number of studies have used the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) approach on bone marrow. The purpose of this study was to qualitatively and quantitatively compare the clinical value of IVIM based on field-of-view optimized and constrained undistorted single shot (FOCUS) with the standard single-shot echo-planar imaging (ss-EPI) in the vertebral bone marrow. MATERIALS AND METHODS Twenty healthy volunteers underwent ss-EPI and FOCUS IVIM-DWI of the lumbar spine. Intravoxel incoherent motion parameters (the apparent diffusion coefficient [ADC], true diffusion coefficient [D], pseudodiffusion coefficient [D*], and perfusion fraction [f]) were calculated. RESULTS The FOCUS IVIM protocol allowed for measurement of ADC, D, D*, and f in all volunteers: ADC, 0.28 ± 1.33 ×10-3 mm2/s; D = 0.25 ± 3.98 ×10-3 mm2/s, f = 0.36 ± 4.01; and D* = 102.16 ± 71.21 ×10-3 mm2/s. There were no significant differences between the values of ADC, D, and f obtained with ss-EPI and FOCUS. The D* was significantly different (P < 0.05) between ss-EPI and FOCUS IVIM. Image quality assessments showed that the image qualities of FOCUS were superior to ss-EPI (P < 0.001). CONCLUSIONS As a high-resolution IVIM-DWI technique, the FOCUS technique has potential clinical utility in evaluating the diffusion and perfusion in the vertebral bone marrow.
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Xie S, Masokano IB, Liu W, Long X, Li G, Pei Y, Li W. Comparing the clinical utility of single-shot echo-planar imaging and readout-segmented echo-planar imaging in diffusion-weighted imaging of the liver at 3 tesla. Eur J Radiol 2020; 135:109472. [PMID: 33370640 DOI: 10.1016/j.ejrad.2020.109472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/26/2020] [Accepted: 12/08/2020] [Indexed: 01/09/2023]
Abstract
PURPOSE To compare the clinical utility of single-shot echo-planar imaging (SS-EPI) using different breathing schemes and readout-segmented EPI (RS-EPI) in the repeatability of apparent diffusion coefficient (ADC) measurements, signal-to-noise ratio (SNR) and image quality. METHODS In this institutional review board-approved prospective study, hepatic DWIs (b = 50, 300, 600 s/mm2) were performed in 22 volunteers on 3.0 T MRI using SS-EPI with free-breathing diffusion-weighted imaging (FB-DWI), breath-hold (BH-DWI), respiratory-triggered (RT-DWI) and navigator-triggered (NT-DWI), and readout-segmented EPI (RS-DWI). ADC and surrogate SNR (sSNR) were measured in nine anatomic locations in the right lobe, and image quality was assessed on all FB-DWI, BH-DWI, RT-DWI, NT-DWI, and RS-DWI sequences. The sequence with the optimal clinical utility was decided by systematically comparing the ADC repeatability, sSNR and image quality of the above DWIs. RESULTS In all the five sequences, NT-DWI had the most reliable intra-observer agreement (intraclass correlation coefficient (ICC): 0.900-0.922; all P > 0.05), and a better interobserver agreement (ICC: 0.853-0.960; all p > 0.05) than RS-DWI (ICC:0.881-0.916; some P < 0.05). NT-DWI had the best ADC repeatability in the nine locations (mean ADC absolute differences: 38.47-56.38 × 10-6 mm2/s, limits of agreement (LOA): 17.33-22.52 × 10-6 mm2/s). Also, NT-DWI had the highest sSNR (Reader 1: 50.58 ± 20.11 (Superior), 74.06 ± 28.37 (Central), 80.99 ± 38.11(Inferior)); Reader 2: 48.07 ± 23.92 (Superior), 68.23 ± 32.91 (Central), 76.78 ± 33.07 (Inferior)) in three representative sections except for RS-DWI. Furthermore, NT-DWI had a better image quality than RS-DWI (P < 0.05) and was superior to FB-DWI and BH-DWI in sharpness of the liver (at b = 300 s/mm2) (P < 0.05) CONCLUSION: RS-DWI has the best SNR. However, NT-DWI can provide sufficient SNR, excellent image quality, and the best ADC repeatability on 3.0 T MRI. It is thus the recommended sequence for the clinical application of hepatic DWI.
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Affiliation(s)
- Simin Xie
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Ismail Bilal Masokano
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Wenguang Liu
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Xueying Long
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Guijin Li
- Siemens Healthcare Ltd, Guangzhou Branch, 510620, China
| | - Yigang Pei
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China; Postdoctoral Fellow, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
| | - Wenzheng Li
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
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Abstract
Prostate MRI has seen increasing interest in recent years and has led to the development of new MRI techniques and sequences to improve prostate cancer (PCa) diagnosis which are reviewed in this article. Numerous studies have focused on improving image quality (segmented DWI) and faster acquisition (compressed sensing, k-t-SENSE, PROPELLER). An increasing number of studies have developed new quantitative and computer-aided diagnosis methods including artificial intelligence (PROSTATEx challenge) that mitigate the subjective nature of mpMRI interpretation. MR fingerprinting allows rapid, simultaneous generation of quantitative maps of multiple physical properties (T1, T2), where PCa are characterized by lower T1 and T2 values. New techniques like luminal water imaging (LWI), restriction spectrum imaging (RSI), VERDICT and hybrid multi-dimensional MRI (HM-MRI) have been developed for microstructure imaging, which provide information similar to histology. The distinct MR properties of tissue components and their change with the presence of cancer is used to diagnose prostate cancer. LWI is a T2-based imaging technique where long T2-component corresponding to luminal water is reduced in PCa. RSI and VERDICT are diffusion-based techniques where PCa is characterized by increased signal from intra-cellular restricted water and increased intracellular volume fraction, respectively, due to increased cellularity. VERDICT also reveal loss of extracellular-extravascular space in PCa due to loss of glandular structure. HM-MRI measures volumes of prostate tissue components, where PCa has reduced lumen and stromal and increased epithelium volume similar to results shown in histology. Similarly, molecular imaging using hyperpolarized 13C imaging has been utilized.
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Plodeck V, Radosa CG, Hübner HM, Baldus C, Borkowetz A, Thomas C, Kühn JP, Laniado M, Hoffmann RT, Platzek I. Rectal gas-induced susceptibility artefacts on prostate diffusion-weighted MRI with epi read-out at 3.0 T: does a preparatory micro-enema improve image quality? Abdom Radiol (NY) 2020; 45:4244-4251. [PMID: 32500236 PMCID: PMC8260527 DOI: 10.1007/s00261-020-02600-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 12/21/2022]
Abstract
Purpose To assess whether the application of a preparatory micro-enema reduces gas-induced susceptibility artefacts on diffusion-weighted MRI of the prostate. Methods 114 consecutive patients who received multiparametric 3 T MRI of the prostate at our institution were retrospectively enrolled. 63 patients self-administered a preparatory micro-enema prior to imaging, and 51 patients underwent MRI without bowel preparation. Two blinded readers independently reviewed the diffusion-weighted sequences regarding gas-induced artefacts. The presence/severity of artefacts was scored ranging from 0 (no artefact) to 3 (severe artefact). A score ≥ 2 was considered a clinically relevant artefact. Maximum rectal width at the level of the prostate was correlated with the administration of a micro-enema. Scores were compared between the scans performed with and without bowel preparation using univariable and multivariable logistic regression, taking into account potential confounding factors (age and prostate volume). Results Significantly less artefacts were found on diffusion-weighted sequences after the administration of a micro-enema shortly prior to MR imaging. Clinically relevant artefacts were found in 10% in the patient group after enema, in 41% without enema. If present, artefacts were also significantly less severe. Mean severity score was 0.3 (enema administered) and 1.2 (no enema), and odds ratio was 0.137 (p < 0.0001) in univariable ordinal logistic regression. Inter-observer agreement was excellent (κ 0.801). Conclusion The use of a preparatory micro-enema prior to 3 T multiparametric prostate MRI significantly reduces both the incidence and severity of gas-induced artefacts on diffusion-weighted sequences and thus improves image quality. Electronic supplementary material The online version of this article (10.1007/s00261-020-02600-9) contains supplementary material, which is available to authorized users.
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Xie M, Ren Z, Bian D, Li D, Yu L, Zhu F, Huang R, Zhang Z, Suye S, Fu C. High resolution diffusion-weighted imaging with readout segmentation of long variable echo-trains for determining myometrial invasion in endometrial carcinoma. Cancer Imaging 2020; 20:66. [PMID: 32958041 PMCID: PMC7507745 DOI: 10.1186/s40644-020-00346-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 09/15/2020] [Indexed: 01/03/2023] Open
Abstract
Background We assessed the image quality of endometrial cancer lesions by readout segmentation of long variable echo-trains (RESOLVE) diffusion-weighted imaging (DWI) compared with that by single-shot echo-planar imaging (SS-EPI) DWI, aimed to explore the value of RESOLVE DWI for determining myometrial invasion and clinical stage in endometrial cancer. Materials and methods From April 2017 to March 2018, a total of 30 endometrial cancer patients (mean age 52.8 ± 9.0 years), who had undergone RESOLVE DWI and SS-EPI DWI, were included in the study. The image quality of endometrial carcinoma by two kinds of DWI scanning methods was compared qualitatively and quantitatively. The Spearman rank correlation test was used to assess the correlation of qualitative image quality scores between two readers. The accuracy of two DWI methods in detecting myometrial invasion and staging of endometrial carcinoma was calculated according to postoperative pathological results. The indexes were analyzed including sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). Results The qualitative score of RESOLVE DWI group was superior to SS-EPI DWI group in every aspect of five aspects (all P < 0.001). Interobserver agreement of depiction was good or excellent in two DWI sequences. Signal to noise ratio and contrast to noise ratio values in RESOLVE DWI group were both higher than those in SS-EPI DWI group (P<0.001). No statistical difference of apparent diffusion coefficient value was observed between two DWI groups (P = 0.261). The specificity, accuracy, PPV, and NPV of estimating myometrial invasion by RESOLVE DWI in three cases (intramucosal lesion, <50% superficial invasion and ≥ 50% deep invasion) were all higher than those by SS-EPI DWI for endometrial carcinoma. Especially RESOLVE DWI was valuable in judging <50% superficial invasion (95%CI:0.586, 0.970). No significant difference in accuracy staging was between the two DWI groups (P = 0.125). Conclusion RESOLVE DWI can provide higher quality images of endometrial carcinoma than SS-EPI DWI. The high-quality images are helpful for precise assessment of myometrial invasion in endometrial cancer.
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Affiliation(s)
- Mengnv Xie
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Zhen Ren
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Dujun Bian
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Dan Li
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Li Yu
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Fang Zhu
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Rui Huang
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Zhibang Zhang
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Suye Suye
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China
| | - Chun Fu
- Department of Obstetrics and Gynecology, The Second Xiangya Hospital, Central South University, Changsha, No.139 Renmin Road, Changsha, Hunan, 410011, PR China.
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Diffusion-Weighted MRI to Assess Sacroiliitis: Improved Image Quality and Diagnostic Performance of Readout-Segmented Echo-Planar Imaging (EPI) Over Conventional Single-Shot EPI. AJR Am J Roentgenol 2020; 217:450-459. [PMID: 32903053 DOI: 10.2214/ajr.20.23953] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND. DWI using single-shot echo-planar imaging (ss-EPI) is prone to artifacts, signal-intensity dropout, and T2* blurring. Readout-segmented echo-planar imaging (rs-EPI) may improve image quality in DWI of the sacroiliac joints. OBJECTIVE. The purposes of this study were, first, to qualitatively and quantitatively compare image quality between ss-EPI and rs-EPI DWI of the sacroiliac joints; and, second, to evaluate whether ADC values derived from ss-EPI and rs-EPI can differentiate disease activity in patients with axial spondyloarthritis (axSpA). METHODS. This retrospective study included 75 patients who underwent ss-EPI and rs-EPI DWI of the sacroiliac joints. Patients were classified into axSpA (n = 50) and no-ax-SpA (n = 25) groups on the basis of Assessment of SpondyloArthritis International Society (ASAS) criteria. Patients in the axSpA group were assigned to one of four disease activity states using the Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP). Two radiologists independently assessed qualitative (overall image quality and diagnostic confidence) and quantitative (ADC, signal-to-noise ratio [SNR], and contrast-to-noise ratio [CNR]) imaging parameters. RESULTS. Readout-segmented EPI provided significantly better overall image quality, diagnostic confidence, SNR, and CNR than ss-EPI (both readers, p < .001). In patients with axSpA, the correlation coefficients (r) of ADC values and ASDAS-CRP values were 0.456 and 0.458 for ss-EPI and 0.537 and 0.558 for rs-EPI. ADCs showed progressive increases with increasing activity state for both sequences, although these increases were more substantial for rs-EPI than for ss-EPI. Across readers, median ADCs for ss-EPI were 0.243 and 0.234 × 10-3 mm2/s for inactive disease, 0.411 and 0.412 × 10-3 mm2/s for moderate disease activity, 0.499 and 0.447 × 10-3 mm2/s for high activity, and 0.671 and 0.575 × 10-3 mm2/s for very high activity (reader 1, p = .011; reader 2, p = .010). Across readers, ADCs for rs-EPI were 0.236 and 0.236 × 10-3 mm2/s for inactive disease, 0.483 and 0.477 × 10-3 mm2/s for moderate disease activity, 0.727 and 0.692 × 10-3 mm2/s for high activity, and 0.902 and 0.803 × 10-3 mm2/s for very high activity (reader 1, p = .002; reader 2, p = .001). ADC values for ss-EPI were significantly different only between the inactive and very high disease activity groups (p < .0083, Bonferroni-corrected threshold). ADC values for rs-EPI were significantly different between the inactive and high, inactive and very high, as well as the moderate and very high disease activity groups (p < .0083, Bonferroni-corrected threshold). CONCLUSION. Readout-segmented EPI significantly improves the image quality of DWI in imaging the sacroiliac joints. In patients with axSpA, activity states are better differentiated by rs-EPI than by ss-EPI. CLINICAL IMPACT. Readout-segmented EPI is a more robust tool than ss-EPI for imaging of axSpA and should be included in routine clinical protocols for MRI of the sacroiliac joints.
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Bergen RV, Ryner L, Essig M. Field-map correction in read-out segmented echo planar imaging for reduced spatial distortion in prostate DWI for MRI-guided radiotherapy applications. Magn Reson Imaging 2019; 67:43-49. [PMID: 31843418 DOI: 10.1016/j.mri.2019.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/15/2019] [Accepted: 12/07/2019] [Indexed: 11/15/2022]
Abstract
Diffusion-weighted echo planar imaging (DW-EPI) suffers from geometric distortion due to low phase-encoding bandwidth. Read-out segmented echo planar imaging (RS-EPI) reduces distortion but residual distortion remains in extreme cases. Additional corrections need to be applied, especially for radiotherapy applications where a high degree of accuracy is needed. In this study the use of magnetic field map corrections are assessed in DW-EPI and RS-EPI, to reduce geometric uncertainty for MRI-guided radiotherapy applications. Magnetic field maps were calculated from gradient echo images and distortion corrections were applied to RS-EPI images. Distortions were assessed in a prostate phantom by comparing to the known geometry, and in vivo using a modified Hausdorff distance metric using a T2-weighted spin echo as ground truth. Across 10 patients, field map-corrected RS-EPI reduced maximum distortion by 5 mm on average compared to DW-EPI (σ = 1.9 mm). Geometric distortions were also reduced significantly using field mapping with RS-EPI, compared to RS-EPI alone (p ≤ 0.05). The increased geometric accuracy of these techniques can potentially allow diffusion-weighted images to be fused with other MR or CT images for radiotherapy treatment purposes.
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Affiliation(s)
- Robert V Bergen
- Department of Physics & Astronomy, University of Manitoba, Canada; Medical Physics, CancerCare Manitoba, Canada
| | - Lawrence Ryner
- Department of Physics & Astronomy, University of Manitoba, Canada; Medical Physics, CancerCare Manitoba, Canada.
| | - Marco Essig
- Department of Radiology, University of Manitoba, Canada
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Caglic I, Barrett T. Optimising prostate mpMRI: prepare for success. Clin Radiol 2019; 74:831-840. [PMID: 30611559 DOI: 10.1016/j.crad.2018.12.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/06/2018] [Indexed: 01/06/2023]
Abstract
Multiparametric magnetic resonance imaging (MRI) now plays an essential role in prostate cancer diagnosis and management. The increasing use of MRI before biopsy makes obtaining images of the highest quality vital. The European Society of Urogenital Radiology (ESUR) 2012 guidelines and subsequent Prostate Imaging -Reporting Data System (PI-RADS) version 2 recommendations in 2015 address the technical considerations for optimising MRI acquisition; however, the quality of the multiparametric sequences employed depends not only on the hardware and software utilised and scanning parameters selected, but also on patient-related factors, for which current guidance is lacking. Patient preparation factors include bowel peristalsis, rectal distension, the presence of total hip replacement (THR), post-biopsy haemorrhage, and abstinence from ejaculation. New evidence has been accrued since the release of PI-RADS v2, and this review aims to explore the key issues of patient preparation and their potential to further optimise the image quality of mpMRI.
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Affiliation(s)
- I Caglic
- Department of Radiology, Norfolk & Norwich University Hospital, Norwich, UK; Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
| | - T Barrett
- Department of Radiology, Addenbrooke's Hospital and University of Cambridge, Cambridge, UK; CamPARI Clinic, Addenbrooke's Hospital and University of Cambridge, Cambridge, UK
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Chen H, Chen L, Liu F, Lu J, Xu C, Wang L. Diffusion-weighted magnetic resonance imaging in bladder cancer: comparison of readout-segmented and single-shot EPI techniques. Cancer Imaging 2019; 19:59. [PMID: 31455403 PMCID: PMC6712649 DOI: 10.1186/s40644-019-0245-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 08/05/2019] [Indexed: 02/07/2023] Open
Abstract
Background To evaluate whether readout-segment echo-planar imaging (RS-EPI) can provide better image quality in assessing bladder cancer than single-shot echo-planar imaging (SS-EPI) and to compare quantitative imaging parameters derived from both techniques. Methods Seventy patients with bladder lesions were enrolled and underwent diffusion-weighted imaging on a 3 Tesla magnetic resonance scanner using axial RS-EPI and SS-EPI techniques. Two observers independently assessed the susceptibility, detectability, motion artefacts and blurring of the images using qualitative scores. The signal-to-noise ratio (SNR), signal intensity ratio (SIR), contrast-to-noise ratio (CNR) and ADC values of the bladder lesions were measured and compared between the two techniques and between two observers. Qualitative and quantitative comparisons of image quality were performed using the Wilcoxon signed-rank test and paired t-test. In addition, the agreement of the ADC measurements was evaluated using ICC values and Bland-Altman plots. Results Sixty-eight patients were included in the final analysis. The scores of image susceptibility, detectability and blurring for RS-EPI were significantly higher than those for SS-EPI (all p < 0.05), while the motion artefact was not. There were significant differences between RS-EPI and SS-EPI in the CNR and SIR values (all p < 0.05) but not in the SNR or ADC values (all p > 0.05). The ICC values and Bland-Altman plots also showed excellent agreement between the measured ADC values of the bladder lesions. Conclusions The RS-EPI technique provides significantly better image quality in patients with bladder cancer than the SS-EPI technique, without a significant difference in the ADC value.
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Affiliation(s)
- Haihu Chen
- Department of Radiology, Changhai Hospital of Shanghai, The Second Military Medical University, No.168 Changhai Road, Shanghai, 200433, China
| | - Luguang Chen
- Department of Radiology, Changhai Hospital of Shanghai, The Second Military Medical University, No.168 Changhai Road, Shanghai, 200433, China
| | - Fang Liu
- Department of Radiology, Changhai Hospital of Shanghai, The Second Military Medical University, No.168 Changhai Road, Shanghai, 200433, China
| | - Jianping Lu
- Department of Radiology, Changhai Hospital of Shanghai, The Second Military Medical University, No.168 Changhai Road, Shanghai, 200433, China
| | - Chuanliang Xu
- Department of Urology, Changhai Hospital of Shanghai, The Second Military Medical University, No.168 Changhai Road, Shanghai, 200433, China.
| | - Li Wang
- Department of Radiology, Changhai Hospital of Shanghai, The Second Military Medical University, No.168 Changhai Road, Shanghai, 200433, China.
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Zhang Z, Song C, Zhang Y, Wen B, Zhu J, Cheng J. Apparent diffusion coefficient (ADC) histogram analysis: differentiation of benign from malignant parotid gland tumors using readout-segmented diffusion-weighted imaging. Dentomaxillofac Radiol 2019; 48:20190100. [PMID: 31265331 DOI: 10.1259/dmfr.20190100] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES To explore the utility of whole-lesion apparent diffusion coefficient (ADC) histogram analysis for differentiating parotid gland tumors following readout-segmented diffusion-weighted imaging (RESOLVE). METHODS 80 patients (40 with pleomorphic adenomas, 14 with Warthin tumors, and 26 with malignant parotid gland tumors) who underwent routine head-and-neck MRI and RESOLVE examinations, were retrospectively evaluated. RESOLVE data were acquired from a MAGNETOM Skyra 3T MR system. Eleven whole-lesion histogram parameters derived from histogram analysis (ADC_mean, ADC_minimum, ADC_maximum, ADC_1th, ADC_10th, ADC_50th, ADC_90th, ADC_99th, skewness, variance and kurtosis) were calculated for each patient using MaZda. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of the ADC for distinguishing among the three groups. RESULTS In total, nine parameters (ADC_minimum, ADC_maximum, ADC_mean, ADC_10th, ADC_50th, ADC_90th, ADC_99th, variance, skewness) were statistically significant (all p < 0.05) for all three groups, in the comparison of pleomorphic adenomas to Warthin tumors; the ADC_mean, ADC_50th, and skewness revealed high diagnostic efficiency with areas under the receiver operating characteristic curve of 0.976, 0.970, and 0.970, respectively. In the comparison of pleomorphic adenomas to malignant parotid gland tumors, these nine parameters were also found to be statistically different (all p < 0.05); the ADC_mean, ADC_10th and ADC_50th revealed high diagnostic efficiency with area under the curve of 0.851, 0.866, and 0.841, respectively. However, in the comparison of Warthin tumors to malignant parotid gland tumors, only three parameters (ADC_mean, ADC_50th, skewness) were statistically significant (all p < 0.05). CONCLUSIONS Whole-lesion ADC histograms are effective in differentiating common parotid gland tumors.
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Affiliation(s)
- Zanxia Zhang
- Department of Radiology, The first Affiliated Hospital of Zhengzhou University, Zhengzhou, P. R. China
| | - Chengru Song
- Department of Radiology, The first Affiliated Hospital of Zhengzhou University, Zhengzhou, P. R. China
| | - Yong Zhang
- Department of Radiology, The first Affiliated Hospital of Zhengzhou University, Zhengzhou, P. R. China
| | - Baohong Wen
- Department of Radiology, The first Affiliated Hospital of Zhengzhou University, Zhengzhou, P. R. China
| | - Jinxia Zhu
- MR Collaboration, Siemens Healthcare, Beijing, China
| | - Jingliang Cheng
- Department of Radiology, The first Affiliated Hospital of Zhengzhou University, Zhengzhou, P. R. China
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Ho MJ, Ciritsis A, Manoliu A, Stieltjes B, Marcon M, Andreisek G, Kuhn FP. Diffusion Tensor Imaging of the Brachial Plexus: A Comparison between Readout-segmented and Conventional Single-shot Echo-planar Imaging. Magn Reson Med Sci 2018; 18:150-157. [PMID: 30416178 PMCID: PMC6460122 DOI: 10.2463/mrms.mp.2018-0004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose: Diffusion tensor imaging (DTI) adds functional information to morphological magnetic resonance neurography (MRN) in the assessment of the brachial nerve plexus. To determine the most appropriate pulse sequence in scan times suited for diagnostic imaging in clinical routine, we compared image quality between simultaneous multi-slice readout-segmented (rs-DTI) and conventional single-shot (ss-DTI) echo-planar imaging techniques. Methods: Institutional Review Board (IRB) approved study including 10 healthy volunteers. The supraclavicular brachial plexus, covering the nerve roots and trunks from C5 to C7, was imaged on both sides with rs-DTI and ss-DTI. Both sequences were acquired in scan times <7 min with b-values of 900 s/mm2 and with isotropic spatial resolution. Results: In rs-DTI image, the overall quality was significantly better and distortion artifacts were significantly lower (P = 0.001–0.002 and P = 0.001–0.002, respectively) for both readers. In ss-DTI, a trend toward lower degree of ghosting and motion artifacts was elicited (reader 1, P = 0.121; reader 2, P = 0.264). No significant differences between the two DTI techniques were found for signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR) and fractional anisotropy (FA) (P ≥ 0.475, P ≥ 0.624, and P ≥ 0.169, respectively). Interreader agreement for all examined parameters and all sequences ranged from intraclass correlation coefficient (ICC) 0.064 to 0.905 and Kappa 0.40 to 0.851. Conclusion: Incomparable acquisition times rs-DTI showed higher image quality and less distortion artifacts than ss-DTI. The trend toward a higher degree of ghosting and motion artifacts in rs-DTI did not deteriorate image quality to a significant degree. Thus, rs-DTI should be considered for functional MRN of the brachial plexus.
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Affiliation(s)
- Michael J Ho
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich.,Department of Neuroradiology, University Hospital Freiburg
| | - Alexander Ciritsis
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich
| | - Andrei Manoliu
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich
| | | | - Magda Marcon
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich
| | | | - Felix Pierre Kuhn
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich
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19
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Qian W, Chen Q, Zhang Z, Wang H, Zhang J, Xu J. Comparison between readout-segmented and single-shot echo-planar imaging in the evaluation of cervical cancer staging. Br J Radiol 2018; 92:20180293. [PMID: 30359094 DOI: 10.1259/bjr.20180293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE: To compare the performance of diffusion-weighted imaging (DWI) based on readout-segmented echo-planar imaging (RESOLVE) and single-shot EPI (SS-EPI) sequence in evaluating cervical cancer staging. METHODS: 61 patients with cervical cancer underwent DWI based on SS-EPI and RESOLVE. Two blinded readers independently assessed two sets of DW images for distinction of anatomical structures, delineation of lesion, susceptibility artefact and overall image quality on a 4-point scale. Geometric distortion was evaluated by measuring lesion anteroposterior (AP) length and left-right (LR) width derived from T2W images and those obtained from the corresponding DW images. Staging of cervical cancer on SS-EPI and RESOLVE were compared with T2WI and gold-standard of pathological findings. RESULTS: RESOLVE was significantly superior to SS-EPI for all four criteria regarding qualitative comparisons (all p < 0.05). Regarding the geometric distortion, AP length on SS-EPI was significantly different from that of T2WI (p < 0.05), whereas there were no significant differences between RESOLVE and T2WI (both p > 0.05). The staging of SS-EPI was overestimated, while RESOLVE had a better consistency with pathological staging than SS-EPI in staging of cervical cancer. There was no significant difference in apparent diffusion coefficient value between SS-EPI and RESOLVE (p < 0.05). CONCLUSION: RESOLVE is superior to SS-EPI in the accuracy of cervical cancer staging because of the improvement in image quality. ADVANCES IN KNOWLEDGE: RESOLVE has a more accurate value comparable to SS-EPI in cervical cancer staging, with the advantage of the improvement in image quality and reduced geometric distortion.
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Affiliation(s)
- Weiliang Qian
- 1 Department of Radiology, The Affiliated Suzhou Hospital of Nanjing Medical University , Suzhou , People's Republic of China
| | - Qian Chen
- 1 Department of Radiology, The Affiliated Suzhou Hospital of Nanjing Medical University , Suzhou , People's Republic of China
| | - Zhongshuai Zhang
- 2 Diagnosis Imaging, Siemens Healthcare Ltd , Shanghai , Republic of China
| | - Hong Wang
- 1 Department of Radiology, The Affiliated Suzhou Hospital of Nanjing Medical University , Suzhou , People's Republic of China
| | - Jibin Zhang
- 1 Department of Radiology, The Affiliated Suzhou Hospital of Nanjing Medical University , Suzhou , People's Republic of China
| | - Jianming Xu
- 1 Department of Radiology, The Affiliated Suzhou Hospital of Nanjing Medical University , Suzhou , People's Republic of China
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20
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Clinical applications of diffusion weighted imaging in neuroradiology. Insights Imaging 2018; 9:535-547. [PMID: 29846907 PMCID: PMC6108979 DOI: 10.1007/s13244-018-0624-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/12/2018] [Accepted: 03/20/2018] [Indexed: 12/21/2022] Open
Abstract
Abstract Diffusion-weighted imaging (DWI) has revolutionised stroke imaging since its introduction in the mid-1980s, and it has also become a pillar of current neuroimaging. Diffusion abnormalities represent alterations in the random movement of water molecules in tissues, revealing their microarchitecture, and occur in many neurological conditions. DWI provides useful information, increasing the sensitivity of MRI as a diagnostic tool, narrowing the differential diagnosis, providing prognostic information, aiding in treatment planning and evaluating response to treatment. Recently, there have been several technical improvements in DWI, leading to reduced acquisition time and artefacts and enabling the development of diffusion tensor imaging (DTI) as a tool for assessing white matter. We aim to review the main clinical uses of DWI, focusing on the physiological mechanisms that lead to diffusion abnormalities. Common pitfalls will also be addressed. Teaching Points • DWI includes EPI, TSE, RESOLVE or EPI combined with reduced volume excitation. • DWI is the most sensitive sequence in stroke diagnosis and provides information about prognosis. • DWI helps in the detection of intramural haematomas (arterial dissection). • In diffusion imaging, ADC is inversely proportional to tumour cellularity. • DWI and DTI derived parameters can be used as biomarkers in different pathologies.
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21
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Wengler K, Tank D, Fukuda T, Paci JM, Huang M, Schweitzer ME, He X. Diffusion tensor imaging of human Achilles tendon by stimulated echo readout-segmented EPI (ste-RS-EPI). Magn Reson Med 2018; 80:2464-2474. [PMID: 29732609 DOI: 10.1002/mrm.27220] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/13/2018] [Accepted: 03/26/2018] [Indexed: 11/11/2022]
Abstract
PURPOSE Healing, regeneration, and remodeling of the injured Achilles tendon are associated with notable changes in tendon architecture. However, assessing Achilles microstructural properties with conventional diffusion tension imaging (DTI) remains a challenge because of very short T2 / <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msubsup><mml:mi>T</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo></mml:msubsup> </mml:mrow> </mml:math> values of the tendon. Hence, the objective of this study was to develop a novel Achilles tendon DTI protocol for a non-invasive investigation of the changes of microstructural integrity in tendinopathy. METHODS A novel stimulated echo readout-segmented EPI (ste-RS-EPI) DTI sequence was proposed to achieve a TE of ∼14-20 ms for typical b-values of 400-800 s/mm2 on clinical 3T MRI scanners. To further boost tendon MR signal, the Achilles was positioned at the magic angle (∼55 °) with respect to the scanner B0 field. The sensitivity of the developed protocol was evaluated in 19 healthy participants and 6 patients with clinically confirmed tendinopathy. RESULTS Compared to spin echo RS-EPI DTI protocol, ste-RS-EPI provided an ∼100-200% increase in Achilles MR signal. Tendinopathic Achilles demonstrated a high degree of microstructural disruption based on DTI tractography analysis, with significantly lower (P < 0.05) axial diffusivity (1.20 ± 0.19 vs. 1.39 ± 0.10 × 10-3 mm2 /s), radial diffusivity (0.72 ± 0.11 vs. 0.81 ± 0.08 × 10-3 mm2 /s), and mean diffusivity (0.87 ± 0.14 vs. 1.00 ± 0.07 × 10-3 mm2 /s), but no significant difference in fractional anisotropy (0.38 ± 0.04 vs. 0.38 ± 0.05; P = 0.86). CONCLUSION Achilles tendon ste-RS-EPI DTI can non-invasively detect the tendinopathy-induced changes to microstructural integrity, consistent with the disruption of collagen arrangement and increased cellularity. This study demonstrated the robustness and sensitivity of the proposed protocol in Achilles tendinopathy.
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Affiliation(s)
- Kenneth Wengler
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Dharmesh Tank
- Department of Radiology, Stony Brook University, Stony Brook, New York
| | - Takeshi Fukuda
- Department of Radiology, Stony Brook University, Stony Brook, New York
| | - James M Paci
- Department of Orthopaedic Surgery, Stony Brook University, Stony Brook, New York
| | - Mingqian Huang
- Department of Radiology, Stony Brook University, Stony Brook, New York
| | - Mark E Schweitzer
- Department of Radiology, Stony Brook University, Stony Brook, New York
| | - Xiang He
- Department of Radiology, Stony Brook University, Stony Brook, New York
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22
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Hwang J, Hong SS, Kim HJ, Chang YW, Nam BD, Oh E, Lee E, Cha H. Reduced field-of-view diffusion-weighted MRI in patients with cervical cancer. Br J Radiol 2018; 91:20170864. [PMID: 29630391 DOI: 10.1259/bjr.20170864] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE Diffusion-weighted imaging (DWI) with reduced field-of-view (FOV) has been shown to provide high spatial resolution with reduced distorsion in the spinal cord, breast, pancreas, and prostate gland. Therefore, we performed this study to evaluate the qualitative image quality and quantitative ADC value of reduced FOV DWI in patients with cervical cancer in comparison with conventional DWI. METHODS This study retrospectively included 22 patients (mean age, 53.9 years) with biopsy-proven cervical cancer who underwent pelvic MR imaging including conventional DWI and reduced FOV DWI before therapy. Two observers independently rated image quality for reduced FOV DWI and conventional DWI regarding anatomic detail, lesion conspicuity, presence of artifacts, and overall image quality using the following 4-point scale. Quantitative analysis was performed by measuring the ADC value of the tumor. The Wilcoxon signed-rank test was used to compare qualitative scores and mean ADC value between two DWI sequences. RESULTS Reduced FOV DWI achieved significantly better anatomic detail, lesion conspicuity, presence of artifacts, and overall image quality compared to conventional DWI (p < 0.05). There was no significant difference in mean tumor ADC value between the two DWI sequences (0.990 × 10-3 mm2 s-1 ± 0.364 at reduced FOV DWI vs 1.253 × 10-3 mm2 s-1 ± 0.387 at conventional DWI) (p = 0.067). CONCLUSION Reduced FOV DWI shows better image quality in terms of anatomic detail and lesion conspicuity with fewer artifacts compared to conventional DWI. Advance in knowledge: Reduced FOV DWI may enhance diagnostic performance for evaluation of cervical cancer.
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Affiliation(s)
- Jiyoung Hwang
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - Seong Sook Hong
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - Hyun-Joo Kim
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - Yun-Woo Chang
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - Bo Da Nam
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - Eunsun Oh
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - EunJi Lee
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
| | - Hwajin Cha
- 1 Department of Radiology, Soonchunhyang University College of Medicine, Seoul Hospital , Seoul , Republic of Korea
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23
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Comparison of DWI Methods in the Pediatric Brain: PROPELLER Turbo Spin-Echo Imaging Versus Readout-Segmented Echo-Planar Imaging Versus Single-Shot Echo-Planar Imaging. AJR Am J Roentgenol 2018; 210:1352-1358. [PMID: 29570373 DOI: 10.2214/ajr.17.18796] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The purpose of this study is to compare DWI for pediatric brain evaluation using single-shot echo-planar imaging (EPI), periodically rotated overlapping parallel lines with enhanced reconstruction (Blade), and readout-segmented EPI (Resolve). MATERIALS AND METHODS Blade, Resolve, and single-shot EPI were performed for 27 pediatric patients (median age, 9 years), and three datasets were independently reviewed by two radiologists. Qualitative analyses were performed for perceptive coarseness, image distortion, susceptibility-related changes, motion artifacts, and lesion conspicuity using a 5-point Likert scale. Quantitative analyses were conducted for spatial distortion and signal uniformity of each sequence. RESULTS Mean scores were 2.13, 3.17, and 3.76 for perceptive coarseness; 4.85, 3.96, and 2.19 for image distortion; 4.76, 3.96, and 2.30 for susceptibility-related change; 4.96, 3.83, and 4.69 for motion artifacts; and 2.71, 3.75, and 1.92 for lesion conspicuity, for Blade, Resolve, and single-shot EPI, respectively. Blade and Resolve showed better quality than did single-shot EPI for image distortion, susceptibility-related changes, and lesion conspicuity. Blade showed less image distortion, fewer susceptibility-related changes, and fewer motion artifacts than did Resolve, whereas lesion conspicuity was better with Resolve. Blade showed increased signal variation compared with Resolve and single-shot EPI (coefficients of variation were 0.10, 0.08, and 0.05 for lateral ventricle; 0.13, 0.09, and 0.05 for centrum semiovale; and 0.16, 0.09, and 0.06 for pons in Blade, Resolve, and single-shot EPI, respectively). CONCLUSION DWI with Resolve or Blade yields better quality regarding distortion, susceptibility-related changes, and lesion conspicuity, compared with single-shot EPI. Blade is less susceptible to motion artifacts than is Resolve, whereas Resolve yields less noise and better lesion conspicuity than does Blade.
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24
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Yokohama T, Iwasaki M, Oura D, Furuya S, Okuaki T. The Reliability of Reduced Field-of-view DTI for Highly Accurate Quantitative Assessment of Cervical Spinal Cord Tracts. Magn Reson Med Sci 2018; 18:36-43. [PMID: 29576582 PMCID: PMC6326762 DOI: 10.2463/mrms.mp.2017-0078] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purpose: To compare the accuracy of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values between reduced FOV or so-called zonally oblique multislice (ZOOM) and conventional diffusion tensor imaging (DTI) in the cervical spinal cord. Methods: Both ZOOM and conventional DTI were performed on 10 healthy volunteers. Intraclass correlation coefficient (ICC) was used to evaluate the reliability of the measurements obtained. Four radiologists evaluated the FA and ADC values at each cervical cord level and classified the visibility by 4 ranks. The geometric distortion ratios of the long axis and short axis were compared between ZOOM and conventional DTI. The imaging parameters were as follows: b-value = 600 s/mm2; TR = 4500 ms; TE = 81 ms; FOV = 70 × 47 mm2 / 200 × 200 mm2; matrix = 80 × 51 / 128 × 126 (ZOOM and conventional DTI, respectively). The region of interest was carefully drawn inside the spinal cord margin to exclude the spinal cord component, without excluding the white matter fiber tracts. Results: The average FA value decreased in both ZOOM and conventional DTI in lower spinal cord levels; in contrast, the ADC value increased in lower spinal cord levels. Zonally oblique multislice DTI was superior to conventional DTI with regard to inter-rater and intra-rater reliability; further, visibility was better and the standard deviation was smaller in ZOOM DTI. On both the long and short axis, the geometric distortion ratio was lower in ZOOM DTI at all cervical spinal cord levels compared with the conventional DTI. There was a significant difference in the distortion ratios of the long and short axis between ZOOM and conventional DTI. Conclusion: Conventional DTI is unreliable owing to its susceptibility to the surrounding magnetic field. ZOOM DTI is reliable for performing highly accurate evaluations.
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Affiliation(s)
| | | | | | - Sho Furuya
- Department of Neurosurgery, Otaru General Hospital
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25
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van Griethuysen JJM, Bus EM, Hauptmann M, Lahaye MJ, Maas M, Ter Beek LC, Beets GL, Bakers FCH, Beets-Tan RGH, Lambregts DMJ. Gas-induced susceptibility artefacts on diffusion-weighted MRI of the rectum at 1.5 T - Effect of applying a micro-enema to improve image quality. Eur J Radiol 2017; 99:131-137. [PMID: 29362144 DOI: 10.1016/j.ejrad.2017.12.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/20/2017] [Accepted: 12/25/2017] [Indexed: 12/20/2022]
Abstract
PURPOSE Assess whether application of a micro-enema can reduce gas-induced susceptibility artefacts in Single-shot Echo Planar Imaging (EPI) Diffusion-weighted imaging of the rectum at 1.5 T. MATERIALS AND METHODS Retrospective analysis of n = 50 rectal cancer patients who each underwent multiple DWI-MRIs (1.5 T) from 2012 to 2016 as part of routine follow-up during a watch-and-wait approach after chemoradiotherapy. From March 2014 DWI-MRIs were routinely acquired after application of a preparatory micro-enema (Microlax®; 5 ml; self-administered shortly before acquisition); before March 2014 no bowel preparation was given. In total, 335 scans were scored by an experienced reader for the presence/severity of gas-artefacts (on b1000 DWI), ranging from 0 (no artefact) to 5 (severe artefact). A score ≥3 (moderate-severe) was considered a clinically relevant artefact. A random sample of 100 scans was re-assessed by a second independent reader to study inter-observer effects. Scores were compared between the scans performed without and with a preparatory micro-enema using univariable and multivariable logistic regression taking into account potential confounding factors (age/gender, acquisition parameters, MRI-hardware, rectoscopy prior to MRI). RESULTS Clinically relevant gas-artefacts were seen in 24.3% (no micro-enema) vs. 3.7% (micro-enema), odds ratios were 0.118 in univariable and 0.230 in multivariable regression (P = 0.0005 and 0.0291). Mean severity score (±SD) was 1.19 ± 1.71 (no-enema) vs 0.32 ± 0.77 (micro-enema), odds ratios were 0.321 (P < 0.0001) and 0.489 (P = 0.0461) in uni- and multivariable regression, respectively. Inter-observer agreement was excellent (κ0.85). CONCLUSION Use of a preparatory micro-enema shortly before rectal EPI-DWI examinations performed at 1.5 T MRI significantly reduces both the incidence and severity of gas-induced artefacts, compared to examinations performed without bowel preparation.
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Affiliation(s)
- Joost J M van Griethuysen
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; GROW School of Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Elyse M Bus
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Michael Hauptmann
- Department of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Max J Lahaye
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Monique Maas
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Leon C Ter Beek
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Geerard L Beets
- GROW School of Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Surgery, the Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Frans C H Bakers
- Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Regina G H Beets-Tan
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; GROW School of Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Doenja M J Lambregts
- Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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Wu W, Miller KL. Image formation in diffusion MRI: A review of recent technical developments. J Magn Reson Imaging 2017; 46:646-662. [PMID: 28194821 PMCID: PMC5574024 DOI: 10.1002/jmri.25664] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/25/2017] [Indexed: 12/13/2022] Open
Abstract
Diffusion magnetic resonance imaging (MRI) is a standard imaging tool in clinical neurology, and is becoming increasingly important for neuroscience studies due to its ability to depict complex neuroanatomy (eg, white matter connectivity). Single-shot echo-planar imaging is currently the predominant formation method for diffusion MRI, but suffers from blurring, distortion, and low spatial resolution. A number of methods have been proposed to address these limitations and improve diffusion MRI acquisition. Here, the recent technical developments for image formation in diffusion MRI are reviewed. We discuss three areas of advance in diffusion MRI: improving image fidelity, accelerating acquisition, and increasing the signal-to-noise ratio. LEVEL OF EVIDENCE 5 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:646-662.
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Affiliation(s)
- Wenchuan Wu
- FMRIB Centre, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Karla L. Miller
- FMRIB Centre, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
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Friedli I, Crowe LA, de Perrot T, Berchtold L, Martin PY, de Seigneux S, Vallée JP. Comparison of readout-segmented and conventional single-shot for echo-planar diffusion-weighted imaging in the assessment of kidney interstitial fibrosis. J Magn Reson Imaging 2017; 46:1631-1640. [DOI: 10.1002/jmri.25687] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/13/2017] [Indexed: 12/27/2022] Open
Affiliation(s)
- Iris Friedli
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Lindsey Alexandra Crowe
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Thomas de Perrot
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Lena Berchtold
- Division of Nephrology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Pierre-Yves Martin
- Division of Nephrology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Sophie de Seigneux
- Division of Nephrology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
| | - Jean-Paul Vallée
- Division of Radiology, Geneva University Hospitals; University of Geneva, Faculty of Medicine; Geneva Switzerland
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Yamashita R, Isoda H, Arizono S, Furuta A, Ohno T, Ono A, Murata K, Togashi K. Selective visualization of pelvic splanchnic nerve and pelvic plexus using readout-segmented echo-planar diffusion-weighted magnetic resonance neurography: A preliminary study in healthy male volunteers. Eur J Radiol 2017; 86:52-57. [DOI: 10.1016/j.ejrad.2016.10.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 10/21/2016] [Accepted: 10/27/2016] [Indexed: 02/02/2023]
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Abstract
Improvements in prostate MR imaging techniques and the introduction of MR imaging-targeted biopsies have had central roles in prostate cancer (PCa) management. The role of MR imaging has progressed from largely staging patients with biopsy-proven PCa to detecting, characterizing, and guiding the biopsy of suspected PCa. These diagnostic advances, combined with improved therapeutic interventions, have led to a more sophisticated and individually tailored approach to patients' unique PCa profile. This review discusses the MR imaging, a standardized reporting scheme, and the role of fusion-targeted prostate biopsy.
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Affiliation(s)
- Hiram Shaish
- Department of Radiology, NYU Langone Medical Center, 550 1st Avenue, New York, NY 10016, USA.
| | - Samir S Taneja
- Division of Urologic Oncology, Department of Urology, NYU Langone Medical Center, 550 1st Avenue, New York, NY 10016, USA
| | - Andrew B Rosenkrantz
- Department of Radiology, NYU Langone Medical Center, 550 1st Avenue, New York, NY 10016, USA
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31
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Ihalainen T, Kuusela L, Soikkeli M, Lantto E, Ovissi A, Sipilä O. A body-sized phantom for evaluation of diffusion-weighted MRI data using conventional, readout-segmented, and zoomed echo-planar sequences. Acta Radiol 2016; 57:947-54. [PMID: 26543056 DOI: 10.1177/0284185115613652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 09/25/2015] [Indexed: 01/22/2023]
Abstract
BACKGROUND Abdominal diffusion-weighted imaging (DWI) has been rapidly increasing during the last few years. For the evaluation of new DWI techniques, the development of suitable phantoms and quality assurance methods is important. PURPOSE To construct a body-diameter phantom for abdominal DWI and study the impact of different acquisition options on image quality. MATERIAL AND METHODS A phantom with a diameter of 31 cm and a volume of 26 L was constructed, containing four samples representing a clinically relevant range of apparent diffusion coefficient (ADC) values. Measurements were carried out on 1.5T and 3.0T MRI systems using conventional echo-planar imaging (EPI), readout-segmented EPI, and zoomed EPI (3.0T) sequences. The effects of parallel imaging, coil intensity normalization, and patient-specific B1 shim (3.0T) were also examined. ADC values and signal-to-noise ratios of the samples were measured, and the level of artifacts was visually evaluated. RESULTS The agreement of ADC values between different acquisition options was generally good, but higher values (by 0.07 × 10(-3) mm(2)/s on the average) with readout-segmented EPI as well as ADC variations of approximately 0.1 × 10(-3) mm(2)/s in slice direction were observed. The image artifacts were reduced by using patient-specific B1 shim, readout-segmented EPI, or zoomed EPI. CONCLUSION The body-sized phantom demonstrated well the expected image artifacts in DWI with large field of view. The use of patient-specific B1 shim, readout-segmented EPI, or zoomed EPI improved image quality of DWI in this study.
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Affiliation(s)
- Toni Ihalainen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Linda Kuusela
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Maiju Soikkeli
- Department of Chemistry, University of Helsinki, Helsinki, Finland
| | - Eila Lantto
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Ali Ovissi
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Outi Sipilä
- HUS Medical Imaging Center, Clinical Physiology and Nuclear Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Friedli I, Crowe LA, Berchtold L, Moll S, Hadaya K, de Perrot T, Vesin C, Martin PY, de Seigneux S, Vallée JP. New Magnetic Resonance Imaging Index for Renal Fibrosis Assessment: A Comparison between Diffusion-Weighted Imaging and T1 Mapping with Histological Validation. Sci Rep 2016; 6:30088. [PMID: 27439482 PMCID: PMC4954968 DOI: 10.1038/srep30088] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/29/2016] [Indexed: 12/12/2022] Open
Abstract
A need exists to noninvasively assess renal interstitial fibrosis, a common process
to all kidney diseases and predictive of renal prognosis. In this translational
study, Magnetic Resonance Imaging (MRI) T1 mapping and a new segmented
Diffusion-Weighted Imaging (DWI) technique, for Apparent Diffusion Coefficient
(ADC), were first compared to renal fibrosis in two well-controlled animal models to
assess detection limits. Validation against biopsy was then performed in 33 kidney
allograft recipients (KARs). Predictive MRI indices, ΔT1 and
ΔADC (defined as the cortico-medullary differences), were compared to
histology. In rats, both T1 and ADC correlated well with fibrosis and inflammation
showing a difference between normal and diseased kidneys. In KARs, MRI indices were
not sensitive to interstitial inflammation. By contrast, ΔADC
outperformed ΔT1 with a stronger negative correlation to fibrosis
(R2 = 0.64 against
R2 = 0.29
p < 0.001). ΔADC tends to negative values
in KARs harboring cortical fibrosis of more than 40%. Using a discriminant analysis
method, the ΔADC, as a marker to detect such level of fibrosis or
higher, led to a specificity and sensitivity of 100% and 71%, respectively. This new
index has potential for noninvasive assessment of fibrosis in the clinical
setting.
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Affiliation(s)
- I Friedli
- Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
| | - L A Crowe
- Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
| | - L Berchtold
- Service of Nephrology, Department of Internal Medicine Specialties, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Geneva, Switzerland
| | - S Moll
- Division of Pathology, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
| | - K Hadaya
- Divisions of Nephrology and Transplantation, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
| | - T de Perrot
- Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
| | - C Vesin
- Division of Cell Physiology and Metabolism, Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
| | - P-Y Martin
- Service of Nephrology, Department of Internal Medicine Specialties, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Geneva, Switzerland
| | - S de Seigneux
- Service of Nephrology, Department of Internal Medicine Specialties, Geneva University Hospitals, University of Geneva, Faculty of Medicine, Geneva, Switzerland
| | - J-P Vallée
- Division of Radiology, Department of Radiology and Medical Informatics Geneva University Hospitals and Faculty of Medicine of the University of Geneva, Switzerland
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Fedorov A, Tuncali K, Panych LP, Fairhurst J, Hassanzadeh E, Seethamraju RT, Tempany CM, Maier SE. Segmented diffusion-weighted imaging of the prostate: Application to transperineal in-bore 3T MR image-guided targeted biopsy. Magn Reson Imaging 2016; 34:1146-54. [PMID: 27240900 DOI: 10.1016/j.mri.2016.05.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/23/2016] [Accepted: 05/24/2016] [Indexed: 11/16/2022]
Abstract
OBJECTIVE This study aims to evaluate the applicability of using single-shot and multi-shot segmented diffusion-weighted imaging (DWI) techniques to support biopsy target localization in a cohort of targeted MRI-guided prostate biopsy patients. MATERIALS AND METHODS Single-shot echo-planar diffusion-weighted imaging (SS-DWI) and multi-shot segmented (MS-DWI) were performed intra-procedurally on a 3Tesla system in a total of 35 men, who underwent in-bore prostate biopsy inside the scanner bore. Comparisons between SS-DWI and MS-DWI were performed with (in 16 men) and without (in 19 men) parallel coil acceleration (iPAT) for SS-DWI. Overall image quality and artifacts were scored by a radiologist and scores were compared with the Wilcoxon-Mann-Whitney rank test. Correlation between the presence of air and image quality scores was evaluated with Spearman statistics. To quantify distortion, the anteroposterior prostate dimension was measured in SS and MS b=0 diffusion- and T2-weighted images. Signal-to-noise ratio was estimated in a phantom experiment. Agreement and accuracy of targeting based on retrospective localization of restricted diffusion areas in DWI was evaluated with respect to the targets identified using multi-parametric MRI (mpMRI). RESULTS Compared to SS-DWI without iPAT, the average image quality score in MS-DWI improved from 2.0 to 3.3 (p<0.005) and the artifact score improved from 2.3 to 1.4 (p<0.005). When iPAT was used in SS-DWI, the average image quality score in MS-DWI improved from 2.6 to 3.3 (p<0.05) and the artifact score improved from 2.1 to 1.4 (p<0.01). Image quality (ρ=-0.74, p<0.0005) and artifact scores (ρ=0.77, p<0.0005) both showed strong correlation with the presence of air in the rectum for the SS-DWI sequence without iPAT. These correlations remained significant when iPAT was enabled (ρ=-0.52, p<0.05 and ρ=0.64, p<0.01). For the comparison MS-DWI vs SS-DWI without iPAT, median differences between diffusion- and T2-weighted image gland measurements were 1.1(0.03-10.4)mm and 4.4(0.5-22.7)mm, respectively. In the SS-DWI-iPAT cohort, median gland dimension differences were 2.7(0.4-5.9)mm and 4.2(0.7-8.9)mm, respectively. Out of the total of 89 targets identified in mpMRI, 20 had corresponding restricted diffusion areas in SS-DWI and 28 in MS-DWI. No statistically significant difference was observed between the distances for the targets in the target-concordant SS- and MS-DWI restricted diffusion areas (5.5mm in SS-DWI vs 4.5mm in MS-DWI, p>0.05). CONCLUSIONS MS-DWI applied to prostate imaging leads to a significant reduction of image distortion in comparison with SS-DWI. There is no sufficient evidence however to suggest that intra-procedural DWI can serve as a replacement for tracking of the targets identified in mpMRI for the purposes of targeted MRI-guided prostate biopsy.
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Affiliation(s)
- Andriy Fedorov
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Kemal Tuncali
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lawrence P Panych
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Janice Fairhurst
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Elmira Hassanzadeh
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ravi T Seethamraju
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Siemens Healthcare, Boston, MA, USA
| | - Clare M Tempany
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Stephan E Maier
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Radiology, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden
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New RESOLVE-Based Diffusional Kurtosis Imaging in MRI-Visible Prostate Cancer: Effect of Reduced b Value on Image Quality and Diagnostic Effectiveness. AJR Am J Roentgenol 2016; 207:330-8. [PMID: 27187062 DOI: 10.2214/ajr.15.15990] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE The purpose of this article was to investigate whether a new readout segmentation of long variable echo-trains (RESOLVE)-based diffusional kurtosis imaging (DKI) with reduced b value technique can affect image quality and diagnostic effectiveness in MRI-visible prostate cancer (PCA). SUBJECTS AND METHODS Prostatic RESOLVE DKI (0-1400 s/mm2) was prospectively performed for 12 volunteers. The optimal protocol was then performed in 108 MRI-visible PCAs to determine whether it can compete against a preferred b-value set (0-2000 s/mm(2)) regarding image quality and diagnostic effectiveness. Images were interpreted by two independent radiologists using the prostate imaging reporting and data system (PI-RADS). Readers' concordance and diagnostic effectiveness were tested with the Fleiss kappa and area under the ROC curve (Az) analyses. RESULTS A b value of 1400 s/mm(2) generated a larger apparent diffusion coefficient of gaussian distribution (Dapp) (1.35 ± 0.31 vs 1.30 ± 0.30 mm(2)/s; p < 0.001) and apparent kurtosis coefficient (Kapp) (1.11 ± 0.26 vs 1.00 ± 0.21; p < 0.001) in PCA than did a b value of 2000 s/mm(2). Interreader agreement using PI-RADS was relatively low when Dapp and Kapp maps were excluded from image interpretations (κ = 0.39-0.41 vs κ = 0.66-0.68 with Dapp and Kapp maps). Interreader agreement in staging PCA was relatively high (κ > 0.80) and was not influenced by reducing the b value. The power of Dapp and Kapp to differentiate PCA from normal tissue (Az = 0.97-0.98), tissue with a Gleason score less than or equal to 3 + 4 from tissue with a Gleason score greater than 3 + 4 (Az = 0.77-0.82), and PCA stage lower than pT3 from stage pT3 and higher PCA (Az = 0.70-0.75) was not significantly degraded by reducing the b value. CONCLUSION We found that b values significantly influenced image quality, PI-RADS score, and DKI outputs but did not degrade the diagnostic effectiveness of DKI parameters to detect and classify PCA.
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Koh DM, Lee JM, Bittencourt LK, Blackledge M, Collins DJ. Body Diffusion-weighted MR Imaging in Oncology: Imaging at 3 T. Magn Reson Imaging Clin N Am 2016; 24:31-44. [PMID: 26613874 DOI: 10.1016/j.mric.2015.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Advances in hardware and software enable high-quality body diffusion-weighted images to be acquired for oncologic assessment. 3.0 T affords improved signal/noise for higher spatial resolution and smaller field-of-view diffusion-weighted imaging (DWI). DWI at 3.0 T can be applied as at 1.5 T to improve tumor detection, disease characterization, and the assessment of treatment response. DWI at 3.0 T can be acquired on a hybrid PET-MR imaging system, to allow functional MR information to be combined with molecular imaging.
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Affiliation(s)
- Dow-Mu Koh
- Department of Radiology, Royal Marsden Hospital, Downs Road, Sutton, SM2 5PT, UK.
| | - Jeong-Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul, South Korea
| | - Leonardo Kayat Bittencourt
- Department of Radiology, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil; CDPI and Multi-Imagem Clinics, Rio de Janeiro, Brazil
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Wu CJ, Wang Q, Zhang J, Wang XN, Liu XS, Zhang YD, Shi HB. Readout-segmented echo-planar imaging in diffusion-weighted imaging of the kidney: comparison with single-shot echo-planar imaging in image quality. Abdom Radiol (NY) 2016; 41:100-8. [PMID: 26830616 DOI: 10.1007/s00261-015-0615-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE The purpose of this study was to compare the image quality of readout-segmented echo-planar imaging (RS-EPI) and that of standard single-shot echo-planar imaging (SS-EPI) in the kidney in a rat model. MATERIALS AND METHODS Twelve Wistar rats undergoing MRI examinations were imaged with two diffusion-weighted (DW) imaging protocols: a standard SS-EPI and a new RS-EPI protocol, both with a 1.0 × 1.0 × 3.0 mm voxel. The two groups of diffusion-weighted images were independently scored on geometric distortion, image blurring, signal dropout, and the overall image quality by two radiologists. Signal-to-noise ratio (SNR) and apparent diffusion coefficient (ADC) were measured on both sequences. Inter-rater agreement (IRA) was evaluated by Fleiss kappa (κ) and inter-class correlation coefficient (ICC) statistics. Comparisons of image qualities were made by Wilcoxon signed-rank test and paired-sample t test. RESULTS Both RS-EPI and SS-EPI had good IRAs in scoring image qualities (κ = 0.607-0.833) and measuring renal ADCs (ICC = 0.828-0.945). Compared to SS-EPI, RS-EPI produced less geometric distortion (median score 1.5 versus 2.5, p < 0.0001), less image blurring (1.75 versus 2.0, p = 0.0003), less signal dropout (1.0 versus 3.0, p = 0.0001), and a lower score in overall image artifacts (4.25 versus 7.25; p < 0.0001). RS-EPI had higher SNR of renal DW images than SS-EPI (p < 0.001). The intra-variability of ADCs in cortex, outer medulla, and inner medulla ranged from 9.6% to 11.1% (Pearson correlation coefficient ρ = 0.675-0.729; p < 0.001) between the two protocols. CONCLUSION We showed that for DWI of the kidney at 1.0 × 1.0 × 3.0 mm(3) voxel sizes, the new protocol provided better image quality than standard SS-EPI protocol.
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Affiliation(s)
- Chen-Jiang Wu
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
| | - Qing Wang
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
| | - Jing Zhang
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
| | - Xiao-Ning Wang
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
| | - Xi-Sheng Liu
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
| | - Yu-Dong Zhang
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
| | - Hai-Bin Shi
- Department of Radiology, The First Affiliated Hospital with Nanjing Medical University, No. 300, Guangzhou Road, Nanjing, 210000, China.
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Foltz WD, Porter DA, Simeonov A, Aleong A, Jaffray D, Chung P, Han K, Ménard C. Readout-segmented echo-planar diffusion-weighted imaging improves geometric performance for image-guided radiation therapy of pelvic tumors. Radiother Oncol 2015; 117:525-31. [DOI: 10.1016/j.radonc.2015.07.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 07/22/2015] [Accepted: 07/29/2015] [Indexed: 11/26/2022]
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Kido A, Fujimoto K, Matsubara N, Kataoka M, Konishi I, Togashi K. A Layer of Decreased Apparent Diffusion Coefficient at the Endometrial-Myometrial Junction in Uterine Adenomyosis. Magn Reson Med Sci 2015; 15:220-6. [PMID: 26607810 PMCID: PMC5600059 DOI: 10.2463/mrms.mp.2015-0084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES To assess the detectability of a low-signal-intensity line within adenomyosis lesions adjacent to the endometrium on apparent diffusion coefficient (ADC) maps, and to establish correlations between these lesions and their possible causes, and more particularly the hormonal changes and magnetic resonance (MR) factors. MATERIALS AND METHODS MR images were obtained from 110 patients with adenomyosis (age 30-57 y.o.) using 3.0 T or 1.5 T MR units. Recognition of the low-signal-intensity line on ADC map was scored using confidence level. The correlation between recognition of the line and the following factors were examined: magnetic field strength, age group, menstrual cycle phases, history of delivery, and hormonal treatments. Presence of the structure corresponding to the low-signal-intensity line on ADC map was evaluated pathologically in the cases that underwent surgery. RESULTS The low-signal-intensity line visible on ADC map was recognized in 55/110 patients. The visibility of the line was not significantly related to hormonal status, age, history of delivery, or magnetic resonance imaging (MRI) magnet strength. There were no corresponding pathological structures. CONCLUSION One half of the adenomyosis patients showed discrepant appearances in T2-weighted (T2WI) vs. ADC map, but no significant relationship with hormonal changes was found in this study. This result may suggest that the low-signal-intensity line within the junctional zone may be related to a functional phenomenon.
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Affiliation(s)
- Aki Kido
- Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University
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Zhao M, Liu Z, Sha Y, Wang S, Ye X, Pan Y, Wang S. Readout-segmented echo-planar imaging in the evaluation of sinonasal lesions: A comprehensive comparison of image quality in single-shot echo-planar imaging. Magn Reson Imaging 2015; 34:166-72. [PMID: 26541548 DOI: 10.1016/j.mri.2015.10.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 08/22/2015] [Accepted: 10/17/2015] [Indexed: 11/18/2022]
Abstract
PURPOSE To investigate the role of readout-segmented echo-planar imaging using parallel imaging and a two-dimensional (2D) navigator (RESOLVE) in the evaluation of sinonasal lesions and to qualitatively and quantitatively compare the image qualities of single-shot echo-planar imaging (SS-EPI) and RESOLVE. MATERIALS AND METHODS Both sinonasal SS-EPI and RESOLVE images were acquired from 32 patients on a 3-T MR scanner. Image quality, lesion conspicuity and the distortions of the SS-EPI and RESOLVE images were qualitatively evaluated by two radiologists. Distortion was also quantitatively evaluated by comparing the distances between the same anatomic points on TSE-T1WI, TSE-T2WI, SS-EPI and RESOLVE images. The apparent diffusion coefficient (ADC) values, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) of the two DWIs were compared. RESULTS The comparisons of the qualitative scores indicated that RESOLVE significantly improved the image quality and lesion conspicuity and reduced the distortion of the sinonasal diseases. The orbit, skull base, temporal bone and upper neck were also better displayed on RESOLVE. Quantitative evaluations revealed that RESOLVE greatly reduced but did not completely remove the distortion. The ADC values of the sinonasal lesions on RESOLVE were lower than those on SS-EPI, whereas no differences were found in the brainstem. The SNR of RESOLVE was lower than that of SS-EPI. There were no differences in the CNRs of the two diffusion-weighted imaging (DWI) techniques. CONCLUSION RESOLVE significantly improved the image quality for evaluations of sinonasal lesions by reducing the susceptibility artifacts, distortion and blurring compared with SS-EPI. RESOVLE offers more accurate ADC values of sinonasal lesions than SS-EPI.
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Affiliation(s)
- Menglong Zhao
- Department of Radiology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Xuhui District, Shanghai 200031, China
| | - Zhuang Liu
- Department of nuclear medicine, Huashan Hospital, Fudan University, No. 12 Mid Wulumuqi Road, Jingan District, Shanghai 200040, China
| | - Yan Sha
- Department of Radiology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Xuhui District, Shanghai 200031, China.
| | - Shenjiang Wang
- Department of Radiology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Xuhui District, Shanghai 200031, China
| | - Xinpei Ye
- Department of Radiology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Xuhui District, Shanghai 200031, China
| | - Yucheng Pan
- Department of Radiology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Xuhui District, Shanghai 200031, China
| | - Shaoyu Wang
- Siemens Ltd., No. 278, Zhouzhu Road, Nanhui, 201318 Shanghai, China
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Feng Z, Min X, Sah VK, Li L, Cai J, Deng M, Wang L. Comparison of field-of-view (FOV) optimized and constrained undistorted single shot (FOCUS) with conventional DWI for the evaluation of prostate cancer. Clin Imaging 2015; 39:851-5. [DOI: 10.1016/j.clinimag.2015.03.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 02/28/2015] [Accepted: 03/10/2015] [Indexed: 01/01/2023]
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