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Purpose: Our purpose was to validate the T1 SIR (T1 score) as an imaging biomarker for the staging of CP in a large, multi-institutional, prospective study., Methods: The prospective study population included 820 participants enrolled in the PROCEED study from nine clinical centers between June 2017 and December 2021. A radiologist at each institution used a standardized method to measure the T1 signal intensity of the pancreas and the reference organs (spleen, paraspinal muscle, liver), which was used to derive respective T1 scores. Participants were stratified according to the seven mechanistic stages of chronic pancreatitis (MSCP 0-6) based on their clinical history, MRCP, and CT findings., Results: The mean pancreas-to-spleen T1 score was 1.30 in participants with chronic abdominal pain, 1.22 in those with acute or recurrent acute pancreatitis, and 1.03 in definite CP. After adjusting for covariates, we observed a linear, progressive decline in the pancreas-to-spleen T1 score with increasing MSCP from 0 to 6. The mean pancreas-to-spleen T1 scores were 1.34 (MSCP 0), 1.27 (MSCP 1), 1.21 (MSCP 2), 1.16 (MSCP 3), 1.18 (MSCP 4), 1.12 (MSCP 5), and 1.05 (MSCP 6) (p < 0.0001). The pancreas-to-liver and pancreas-to-muscle T1 scores showed less linear trends and wider confidence intervals., Conclusion: The T1 score calculated by SIR of the pancreas-to-spleen shows a negative linear correlation with the progression of chronic pancreatitis. It holds promise as a practical imaging biomarker in evaluating disease severity in clinical research and practice., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Motion-induced artifacts have been a major drawback in bladder cancer imaging. This study is to evaluate the clinical utility of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) acquisition in improving motion-induced artifacts in T2-weighted (T2W) magnetic resonance imaging (MRI) of bladder cancer at 3T.Sixteen patient MRI exams were included. Using a Likert scale, 2 radiologists independently scored T2W data without and with PROPELLER in terms of artifact severity and tumor visualization. Statistical analysis was done to assess the image quality improvement by PROPELLER and inter-observer variability.Without PROPELLER, the median scores of artifact severity and tumor visualization were 1.5 and 1.5 for reviewer 1, and 2.0 and 2.0 for reviewer 2. With PROPELLER, the scores increased to 3 and 3.5 for reviewer 1, and 3.5 and 3.5 for reviewer 2. Despite the inter-observer variability (κ scores < 0.2), both reviewers found significant improvement in artifacts and visualization (all P < .001).PROPELLER acquisition significantly improved the image quality of T2W-MRI. These initial findings indicate that this technique should be utilized in clinical MRI of the bladder.

The liver vessels, which have low signal and run next to brighter bile ducts, are difficult to segment from MR images. This study presents a fully automated and adaptive method to segment portal and hepatic veins on magnetic resonance images. In the proposed approach, segmentation of these vessels is achieved in four stages: (i) initial segmentation, (ii) refinement, (iii) reconstruction, and (iv) post-processing. In the initial segmentation stage, k-means clustering is used, the results of which are refined iteratively with linear contrast stretching algorithm in the next stage, generating a mask image. In the reconstruction stage, vessel regions are reconstructed with the marker image from the first stage and the mask image from the second stage. Experimental data sets include slices that show fat tissues, which have the same gray level values with vessels, outside the margin of the liver. These structures are removed in the last stage. Results show that the proposed approach is more efficient than other thresholding-based methods. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Rationale and Objectives: To compare prostate morphology, image quality, and diagnostic performance of 1.5-T endorectal coil magnetic resonance (MR) imaging (MRI) and 3.0-T nonendorectal coil MRI in patients with prostate cancer., Materials and Methods: MR images obtained of 83 patients with prostate cancer using 1.5-T MRI systems with an endorectal coil were compared to images collected from 83 patients with a 3.0-T MRI system. Prostate diameters were measured, and image quality was evaluated by one American Board of Radiology (ABR)-certified radiologist (reader 1) and one ABR-certified diagnostic medical physicist (reader 2). The likelihood of the presence of peripheral zone cancer in each sextant and local extent was rated and compared to histopathologic findings., Results: Prostate anterior-posterior diameter measured by both readers was significantly shorter with 1.5-T endorectal MRI than with 3.0-T MRI. The overall image quality score difference was significant only for reader 1. Both readers found that the two MRI systems provided a similar diagnostic accuracy in cancer localization, extraprostatic extension, and seminal vesicle involvement., Conclusions: Nonendorectal coil 3.0-T MRI provides prostate images that are natural in shape and that have comparable image quality to those obtained at 1.5 T with an endorectal coil, but not superior diagnostic performance. These findings suggest an opportunity exists for improving technical aspects of the 3.0-T prostate MRI., (Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.)

Objectives: The objective of this study was to assess the capability of T2-weighted magnetic resonance imaging (T2W-MRI) and the additional diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) using multitransmit 3 T in the localization of bladder cancer., Materials and Methods: This prospective study was approved by the local institutional review board. Thirty-six patients were included in the study and provided informed consent. Magnetic resonance imaging scans were performed with T2W-MRI and DCE-MRI on a 3-T multitransmit system. Two observers (with 12 and 25 years of experience) independently interpreted T2W-MRI before DCE-MRI data (maps of pharmacokinetic parameters) to localize bladder tumors. The pathological examination of cystectomy bladder specimens was used as a reference criteria standard. The McNemar test was performed to evaluate the differences in sensitivity, specificity, and accuracy. Scores of κ were calculated to assess interobserver agreement., Results: The sensitivity, specificity, and accuracy of the localization with T2W-MRI alone were 81% (29/36), 63% (5/8), and 77% (34/44) for observer 1 and 72% (26/36), 63% (5/8), and 70% (31/44) for observer 2. With additional DCE-MRI available, these values were 92% (33/36), 75% (6/8), and 89% (39/44) for observer 1 and 92% (33/36), 63% (5/8), and 86% (38/44) for observer 2. Dynamic contrast-enhanced MRI significantly (P<0.01) improved the sensitivity and accuracy for observer 2. For the 23 patients treated with chemotherapy, DCE-MRI also significantly (P<0.02) improved the sensitivity and accuracy of bladder cancer localization with T2W-MRI alone for observer 2. Scores of κ were 0.63 for T2W-MRI alone and 0.78 for additional DCE-MRI. Of 7 subcentimeter malignant tumors, 4 (57%) were identified on T2W images and 6 (86%) were identified on DCE maps. Of 11 malignant tumors within the bladder wall thickening, 6 (55%) were found on T2W images and 10 (91%) were found on DCE maps., Conclusions: Compared with conventional T2W-MRI alone, the addition of DCE-MRI improved interobserver agreement as well as the localization of small malignant tumors and those within bladder wall thickening.

Purpose: To evaluate the capability of amide proton transfer (APT) MR imaging for detection of prostate cancer that typically shows a higher tumor cell proliferation rate and cellular density leading to an MRI-detectable overall elevated mobile protein level in higher grade tumors., Materials and Methods: Twelve patients with biopsy-proven prostate cancer were imaged on a 3 Tesla MR imaging system before prostatectomy. APT-MR images were acquired by means of a single-slice single-shot turbo spin echo sequence with a saturation prepulse preparation using 33 different frequency offsets (-8 to 8 ppm, interval 0.5 ppm). For quantification we used the APT ratio (APTR) based on the asymmetry of the magnetization transfer ratio at 3.5 ppm in respect to the water signal. Tumor and peripheral zone benign regions of interest (ROIs) were delineated based on whole mount pathology slides after prostatectomy., Results: APTR in prostate cancer ROIs was 5.8% ± 3.2%, significantly higher than that in the peripheral zone benign regions (0.3% ± 3.2%, P = 0.002)., Conclusion: APT-MR imaging is feasible in prostate cancer detection and has the potential to discriminate between cancer and noncancer tissues., (Copyright © 2011 Wiley-Liss, Inc.)