Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine最新文献

{"title":"Fast Non-contrast MR Angiography Using a Zigzag Centric k_y - k_z k-space Trajectory and Exponential Refocusing Flip Angles with Restoration of Longitudinal Magnetization.","authors":"Vadim Malis, Diana Vucevic, Won C Bae, Asako Yamamoto, Yoshimori Kassai, John Lane, Albert Hsiao, Katsumi Nakamura, Mitsue Miyazaki","doi":"10.2463/mrms.mp.2023-0158","DOIUrl":"10.2463/mrms.mp.2023-0158","url":null,"abstract":"<p><strong>Purpose: </strong>Fresh blood imaging (FBI) utilizes physiological blood signal differences between diastole and systole, causing a long acquisition time. The purpose of this study is to develop a fast FBI technique using a centric k_y - k_z k-space trajectory (cFBI) and an exponential refocusing flip angle (eFA) scheme with fast longitudinal restoration.</p><p><strong>Methods: </strong>This study was performed on 8 healthy subjects and 2 patients (peripheral artery disease and vascular disease) with informed consent, using a clinical 3-Tesla MRI scanner. A numeric simulation using extended phase graph (EPG) and phantom studies of eFA were carried out to investigate the restoration of longitudinal signal by lowering refocusing flip angles in later echoes. cFBI was then acquired on healthy subjects at the popliteal artery station to assess the effect of varying high/low flip ratios on the longitudinal restoration effects. In addition, trigger-delays of cFBI were optimized owing to the long acquisition window in zigzag centric k_y - k_z k-space trajectory. After optimizations, cFBI images were compared against standard FBI (sFBI) images in terms of scan time, motion artifacts, Nyquist N/2 artifacts, blurring, and overall image quality. We also performed two-way repeated measures analysis of variance.</p><p><strong>Results: </strong>cFBI with eFA achieved nearly a 50% scan time reduction compared to sFBI. The high/low flip angle of 180/2 degrees with lower refocusing pulses shows fast longitudinal restoration with the highest blood signals, yet also more sensitive to the background signals. Overall, 180/30 degrees images show reasonable blood signal recovery while minimizing the background signal artifacts. After the trigger delay optimization, maximum intensity projection image of cFBI after systole-diastole subtraction demonstrates less motion and N/2 artifacts than that of sFBI.</p><p><strong>Conclusion: </strong>Together with eFA for fast longitudinal signal restoration, the proposed cFBI technique achieved a 2-fold reduction in scan time and improved image quality without major artifacts.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142134946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical Evaluation of Susceptibility-weighted MR Imaging for the Detection of Intramammary Micro- and Macrocalcifications in 70 Female Patients at 1.5T.","authors":"Annett Lebenatus, Karolin Tesch, Sina Straub, Eike Andreas Strathmann, Lana Bautz, Karl Fritz Werner Schäfer, Dirk Olaf Bauerschlag, Olav Jansen, Mona Salehi Ravesh","doi":"10.2463/mrms.mp.2025-0037","DOIUrl":"https://doi.org/10.2463/mrms.mp.2025-0037","url":null,"abstract":"<p><strong>Purpose: </strong>The ability to accurately detect and characterize intramammary micro- and macrocalcifications without ionized radiation has significant clinical implications for early breast cancer assessment. The aim of this prospective study was to investigate the feasibility of detecting intramammary calcifications using 3D multi-echo gradient echo (ME-GRE) magnitude and true susceptibility-weighted images (tSWI) compared to digital mammography (DM) in patients with different breast sizes and densities of breast parenchyma at 1.5T.</p><p><strong>Methods: </strong>Two board-certified radiologists evaluated digital mammograms of 70 patients and compared them to the corresponding SW-based images concerning detection of intramammary calcifications and determination of their sizes. The clinical performance of both SW-based techniques in accurately detecting and assessing intramammary calcifications was determined. In addition an interobserver agreement was performed.</p><p><strong>Results: </strong>Compared to DM, visualization of calcification lesions using both SW-based techniques is influenced by: 1) Morphology (shape and homogeneity) of calcifications; 2) Spatial arrangement of calcifications. Closely adjacent calcifications may not be distinguishable in the SW-based images as individual lesions. Overlapping susceptibility effects resulted in a single, larger lesion; 3) The (in-phase or out-of-phase cycle) echo time value selected in the imaging protocol plays a crucial role in visualizing the lesions; and 4) Lesion size was overestimated by up to 2.0 mm when comparing SW-based techniques to DM. An almost perfect interobserver agreement was found for the analysis. Microcalcifications could not be visualized. A sensitivity of 13.0% and specificity of 99.7% for the diagnosis of macrocalcifications could be provided with both SW-based techniques.</p><p><strong>Conclusion: </strong>Our findings highlight the potentials and limitations of SW-based techniques at 1.5 T for characterizing intramammary micro- and macrocalcifications. The high specificity of SW-based techniques in combination with higher magnetic field strengths could revolutionize breast cancer screening and management.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145034987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perfusion Signal Analysis Using Multi-pulsed Arterial Spin Labeling (mPASL) with Multiple Post-labeling Delays: Phantom Validation and Application to the Human Foot.","authors":"Vadim Malis, Yoshiki Kuwatsuru, Mitsue Miyazaki","doi":"10.2463/mrms.mp.2025-0047","DOIUrl":"https://doi.org/10.2463/mrms.mp.2025-0047","url":null,"abstract":"<p><strong>Purpose: </strong>This study aims to extend the general kinetic model (GKM) for perfusion signal analysis using multi-pulsed arterial spin labeling (mPASL) acquisitions with multiple post-labeling delays (mPLD). The approach aims to improve accuracy and gain potential for broader experimental and clinical applications.</p><p><strong>Methods: </strong>The magnetization vector evolution of the mPASL technique was analyzed using sequence diagrams and numerical simulation, supplemented by static phantom experiments. The GKM was adapted to support different configurations of mPASL tagging pulses in \"dark\" and \"bright\" methods. The proposed approach was validated on a constant-flow phantom and applied to in-vivo foot perfusion measurements in a cohort of 5 healthy subjects.</p><p><strong>Results: </strong>Simulations showed that the ratio between \"dark\" and \"bright\" mPASL methods is determined by fluid T₁ relaxation time, the number of selective pulses, and labeling efficiency. Experiments with a constant-flow phantom demonstrated that GKM with mPASL enables semi-quantitative perfusion analysis, providing high-temporal-resolution perfusion curves. Estimated perfusion coefficients of constant flow phantom were consistent across acquisitions (5.1% variation), confirming the robustness of the GKM extension for mPASL with multiple post-labeling delays. However, in-vivo results deviated from simulation and constant flow experiments, highlighting potential physiological complexities, and model limitations.</p><p><strong>Conclusion: </strong>Extending the GKM to mPASL acquisitions demonstrates reliable performance under controlled constant flow conditions. Phantom experiments confirmed the accuracy of the approach, while in-vivo measurements in feet revealed deviations from simulation and constant flow results, suggesting the need to account for physiological factors and potential model extension due to pulsatile flow.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144994937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Learning-aided ¹H-MR Spectroscopy for Differentiating between Patients with and without Hepatocellular Carcinoma.","authors":"Jae Seok Bae, Hyeong Hun Lee, Hyeonjin Kim, In Chan Song, Jae Young Lee, Joon Koo Han","doi":"10.2463/mrms.mp.2025-0064","DOIUrl":"https://doi.org/10.2463/mrms.mp.2025-0064","url":null,"abstract":"<p><strong>Purpose: </strong>Among patients with hepatitis B virus-associated liver cirrhosis (HBV-LC), there may be differences in the hepatic parenchyma between those with and without hepatocellular carcinoma (HCC). Proton MR spectroscopy (¹H-MRS) is a well-established tool for noninvasive metabolomics, but has been challenging in the liver allowing only a few metabolites to be detected other than lipids. This study aims to explore the potential of ¹H-MRS of the liver in conjunction with deep learning to differentiate between HBV-LC patients with and without HCC.</p><p><strong>Methods: </strong>Between August 2018 and March 2021, ¹H-MRS data were collected from 37 HBV-LC patients who underwent MRI for HCC surveillance, without HCC (HBV-LC group, n = 20) and with HCC (HBV-LC-HCC group, n = 17). Based on a priori knowledge from the first 10 patients from each group, big spectral datasets were simulated to develop 2 kinds of convolutional neural networks (CNNs): CNNs quantifying 15 metabolites and 5 lipid resonances (qCNNs) and CNNs classifying patients into HBV-LC and HBV-LC-HCC (cCNNs). The performance of the cCNNs was assessed using the remaining patients in the 2 groups (10 HBV-LC and 7 HBV-LC-HCC patients).</p><p><strong>Results: </strong>Using a simulated dataset, the quantitative errors with the qCNNs were significantly lower than those with a conventional nonlinear-least-squares-fitting method for all metabolites and lipids (P ≤0.004). The cCNNs exhibited sensitivity, specificity, and accuracy of 100% (7/7), 90% (9/10), and 94% (16/17), respectively, for identifying the HBV-LC-HCC group.</p><p><strong>Conclusion: </strong>Deep-learning-aided ¹H-MRS with data augmentation by spectral simulation may have potential in differentiating between HBV-LC patients with and without HCC.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144823556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hidden Pitfall in Multiple Sclerosis Imaging: How Standard Susceptibility-Weighted Imaging (SWI) May Miss Paramagnetic Rim Lesions.","authors":"Yuki Sonoda, Akifumi Hagiwara, Yuji Tomizawa, Yasunobu Hoshino, Junko Kikuta, Hideo Kawasaki, Moto Nakaya, Satoru Kamio, Ryutaro Yano, Hiroshi Kusahara, Taku Hatano, Koji Kamagata, Shigeki Aoki","doi":"10.2463/mrms.bc.2025-0073","DOIUrl":"https://doi.org/10.2463/mrms.bc.2025-0073","url":null,"abstract":"<p><p>This case report shows that paramagnetic rim lesions (PRLs), markers of chronic active lesions in multiple sclerosis, vary in visibility depending on scan-parameters of susceptibility-weighted imaging (SWI). Routine SWI for microbleed detection with low flip angle (FA) failed to depict PRLs, while longer TE and higher FA improved visibility. Phase images consistently visualized PRLs. These findings underscore the need to optimize TE and FA, as suboptimal SWI settings may hinder PRL detection.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144823557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiomic Analysis Applied to Pretreatment Gd-EOB-DTPA-enhanced MR Imaging Predicts Response to Selective Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma.","authors":"Yukichi Tanahashi, Takanobu Ikeda, Koh Kubota, Masaya Kutsuna, Tatsunori Kobayashi, Satoshi Funayama, Kumi Ozaki, Shintaro Ichikawa, Satoshi Goshima","doi":"10.2463/mrms.mp.2025-0055","DOIUrl":"https://doi.org/10.2463/mrms.mp.2025-0055","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the efficacy of radiomic analysis applied to pretreatment gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI (Gd-EOB-DTPA-MRI) for predicting the response to transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma.</p><p><strong>Methods: </strong>Data and images from 40 consecutive patients (28 men, 12 women) who underwent pretreatment Gd-EOB-DTPA-MRI and a total of 52 TACE procedures for 75 non-treated hepatocellular carcinomas were retrospectively analyzed. Two radiologists manually outlined lesions on pretreatment arterial- and hepatobiliary-phase hepatic images to extract radiomic features. The radiomics data from one observer were randomly divided into a training dataset and a validation dataset in the ratio of 7:3. Radiomic features extracted using least absolute shrinkage and selection operator (LASSO) binomial regression applied to the training dataset and that showed intraclass correlation coefficients (ICC) >0.7 were used to construct a radiomic model. The predictive performance of the model was evaluated using receiver operating characteristics curves. Lesions classified as showing a complete or partial response according to the modified RECIST criteria were allocated to a response group.</p><p><strong>Results: </strong>There was no significant difference in Child-Pugh score, tumor marker values, or TACE procedure between response and non-response groups. Six radiomic features were selected using the LASSO binomial regression and 5 of them showing an ICC >0.7 were used to establish the radiomic model. The area under the curve of the radiomic model was 0.89 for the training dataset, 0.83 for the validation dataset, and 0.83 for the other observer's data. The sensitivity and specificity for the prediction of tumor response to TACE were 78% and 92% for the training dataset; 71% and 50% for the validation dataset; and 75% and 79% for the other observer's data.</p><p><strong>Conclusion: </strong>The pretreatment Gd-EOB-DTPA-MRI-based radiomic model is useful for predicting the response to TACE of hepatocellular carcinoma.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144823558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MR Imaging of Umbilical Cord Variations, Abnormalities, and Associated Placental Findings.","authors":"Sakiko Kageyama, Tomomi Sato, Noriyuki Iwama, Hirotaka Hamada, Masatoshi Saito, Kei Takase","doi":"10.2463/mrms.rev.2025-0036","DOIUrl":"10.2463/mrms.rev.2025-0036","url":null,"abstract":"<p><p>The umbilical cord and placenta, classified as fetal appendages, play a crucial role in fetal growth and survival. While ultrasonography remains the primary modality for evaluation, MRI provides a more objective and comprehensive assessment, particularly for the placenta and fetus. Although MRI assessment of the umbilical cord is still emerging and not yet widely adopted by radiologists, MRI has the potential to support and complement ultrasound findings, thereby contributing to safer perinatal management. This review summarizes key MRI findings related to the umbilical cord and associated placental abnormalities. In cases where MRI reports are currently unavailable, ultrasound findings are included to supplement the discussion and to support inferences of potential MRI findings, encouraging future diagnostic applications. Initially, we describe the normal morphology and physiological changes of the umbilical cord and placenta, recommended MRI sequences, and normal imaging findings. Placental abnormalities associated with umbilical cord anomalies, including morphological and positional abnormalities, are reviewed. Variations in umbilical cord insertion, particularly marginal and velamentous insertion, as well as vasa previa, are also discussed. Abnormalities related to umbilical cord position and morphology, such as hypercoiling and hypocoiling, cord knots, nuchal cords, and cord presentation, are examined. Additionally, vascular abnormalities, including single umbilical artery, fused umbilical artery, supernumerary vessels, varices, and aneurysms, are explored along with their underlying mechanisms. Finally, umbilical cord cysts and umbilical cord ulcers are addressed. Advancements in imaging technology, particularly Doppler ultrasonography, have significantly improved the detection and management of umbilical cord and placental abnormalities. Understanding these abnormalities in prenatal MRI evaluation is crucial for improving diagnostic accuracy and optimizing perinatal care. MRI may prove to be a useful adjunct when ultrasound findings are inconclusive or when additional anatomical and functional information is needed. However, further studies are needed to clarify MRI's clinical utility.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":"366-386"},"PeriodicalIF":3.2,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12354972/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144755523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive Performance of Radiomic Features Extracted from Breast MR Imaging in Postoperative Upgrading of Ductal Carcinoma in Situ to Invasive Carcinoma.","authors":"Hiroko Satake, Fumie Kinoshita, Satoko Ishigaki, Keita Kato, Yusuke Jo, Satoko Shimada, Norikazu Masuda, Shinji Naganawa","doi":"10.2463/mrms.mp.2023-0168","DOIUrl":"10.2463/mrms.mp.2023-0168","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the predictive performance of radiomic features extracted from breast MRI for upgrade of ductal carcinoma in situ (DCIS) to invasive carcinoma.</p><p><strong>Methods: </strong>This retrospective study included 71 women with DCIS lesions diagnosed preoperatively by biopsy. All women underwent breast dynamic contrast-enhanced (DCE) MRI of the breast, which included pre-contrast and five post-contrast phases continuously with a time resolution of 60s. Lesion segmentation was performed manually, and 144 radiomic features of the lesions were extracted from T2-weighted images (T2WI), pre-contrast T1-weighted images (T1WI), and post-contrast 1st, 2nd, and 5th phase subtraction images on DCE-MRI. Qualitative features of mammography, ultrasound, and MRI were also assessed. Clinicopathological features were evaluated using medical records. The least absolute shrinkage and selection operator (LASSO) algorithm was applied for features selection and model building. The predictive performance of postoperative upgrade to invasive carcinoma was assessed using the area under the receiver operating characteristic curve.</p><p><strong>Results: </strong>Surgical specimens revealed 13 lesions (18.3%) that were upgraded to invasive carcinoma. Among clinicopathological and qualitative features, age was the only significant predictive variable. No significant radiomic features were observed on T2WI and post-contrast 2nd phase subtraction images on DCE-MRI. The area under the curves (AUCs) of the LASSO radiomics model integrated with age were 0.915 for pre-contrast T1WI, 0.862 for post-contrast 1st phase subtraction images, and 0.833 for post-contrast 5th phase subtraction images. The AUCs of the 200-times bootstrap internal validations were 0.885, 0.832, and 0.775.</p><p><strong>Conclusion: </strong>A radiomics approach using breast MRI may be a promising method for predicting the postoperative upgrade of DCIS. The present study showed that the radiomic features extracted from pre-contrast T1WI and post-contrast subtraction images in the very early phase of DCE-MRI were more predictable.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12406154/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140946633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of the Relationship between Respiratory Interval and Temporal Resolution on Image Quality in Free-breathing Abdominal MR Imaging.","authors":"Kazuki Oyama, Mariko Kurashina, Fumihito Ichinohe, Akira Yamada, Yoshihiro Kitoh, Hayato Hayashihara, Shuya Fujihara, Marcel D Nickel, Katsuya Maruyama, Yasunari Fujinaga","doi":"10.2463/mrms.mp.2023-0120","DOIUrl":"10.2463/mrms.mp.2023-0120","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate how the relationship between respiratory interval (RI) and temporal resolution (TR) impacts image quality in free-breathing abdominal MRI (FB-aMRI) using golden-angle radial sparse parallel (GRASP).</p><p><strong>Methods: </strong>Ten healthy volunteers (25.9 ± 2.5 years, four women) underwent 2 mins free-breathing fat-suppression T1-weighted imaging using GRASP at RIs of 3 and 5s (RI₃ and RI₅, respectively) and retrospectively reconstructed at TR of 1.8, 2.9, 4.8, and 7.7s (TR_1.8, TR_2.9, TR_4.8, and TR_7.7, respectively) in each patient. The standard deviation (SD) under the diaphragm was measured using SD maps showing the discrepancy for each horizontal section at all TRs. Two radiologists evaluated image quality (visualization of the right hepatic vein at the confluence of the inferior vena cava, posterior segment branch of portal vein, pancreas, left kidney, and artifacts) at all TRs using a 5-point scale.</p><p><strong>Results: </strong>The SD was significantly higher at TR_1.8 compared to TR_4.8 (P < 0.01) and TR_7.7 (P < 0.001), as well as at TR_2.9 compared to TR_7.7 (P < 0.01) for both RIs. The SD between TR_4.8 and TR_7.7 did not differ for both RIs. For all visual assessment metrics, the TR_1.8 scores were significantly lower than the TR_4.8 and TR_7.7 scores for both RIs. The pancreas and left kidney scores at TR_2.9 were significantly lower than those at TR_7.7 (P < 0.05) for RI₅. Additionally, the left kidney score at TR_1.8 was lower than that at TR_2.9 (P < 0.05) for RI₃. All scores at TR_2.9, TR_4.8, and TR_7.7 were similar for RI₃, while those at TR_4.8 and TR_7.7 were similar for RI₅.</p><p><strong>Conclusion: </strong>Prolonging the TRs compared to RIs enhances image quality in FB-aMRI using GRASP.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12406156/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141066272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thin-slice 2D MR Imaging of the Shoulder Joint Using Denoising Deep Learning Reconstruction Provides Higher Image Quality Than 3D MR Imaging.","authors":"Takahide Kakigi, Ryo Sakamoto, Ryuzo Arai, Akira Yamamoto, Shinichi Kuriyama, Yuichiro Sano, Rimika Imai, Hitomi Numamoto, Kanae Kawai Miyake, Tsuneo Saga, Shuichi Matsuda, Yuji Nakamoto","doi":"10.2463/mrms.mp.2023-0115","DOIUrl":"10.2463/mrms.mp.2023-0115","url":null,"abstract":"<p><strong>Purpose: </strong>This study was conducted to evaluate whether thin-slice 2D fat-saturated proton density-weighted images of the shoulder joint in three imaging planes combined with parallel imaging, partial Fourier technique, and denoising approach with deep learning-based reconstruction (dDLR) are more useful than 3D fat-saturated proton density multi-planar voxel images.</p><p><strong>Methods: </strong>Eighteen patients who underwent MRI of the shoulder joint at 3T were enrolled. The denoising effect of dDLR in 2D was evaluated using coefficient of variation (CV). Qualitative evaluation of anatomical structures, noise, and artifacts in 2D after dDLR and 3D was performed by two radiologists using a five-point Likert scale. All were analyzed statistically. Gwet's agreement coefficients were also calculated.</p><p><strong>Results: </strong>The CV of 2D after dDLR was significantly lower than that before dDLR (P < 0.05). Both radiologists rated 2D higher than 3D for all anatomical structures and noise (P < 0.05), except for artifacts. Both Gwet's agreement coefficients of anatomical structures, noise, and artifacts in 2D and 3D produced nearly perfect agreement between the two radiologists. The evaluation of 2D tended to be more reproducible than 3D.</p><p><strong>Conclusion: </strong>2D with parallel imaging, partial Fourier technique, and dDLR was proved to be superior to 3D for depicting shoulder joint structures with lower noise.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12406157/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141082885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}