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

{"title":"White Matter Microstructural Alterations Mediate the Association between Polygenic Risk for Alzheimer's Disease and Cognitive Performance in Clinically Asymptomatic Adults.","authors":"Rui Zou, Kaito Takabayashi, Christina Andica, Wataru Uchida, Takafumi Kitagawa, Koyo Mizuta, Akifumi Hagiwara, Junko Kikuta, Shigeki Aoki, Koji Kamagata","doi":"10.2463/mrms.mp.2025-0182","DOIUrl":"10.2463/mrms.mp.2025-0182","url":null,"abstract":"<p><strong>Purpose: </strong>Alzheimer's disease (AD) is a progressive neurodegenerative disorder influenced by genetic factors, with a long preclinical phase characterized by subtle alterations in brain microstructure. Although the apolipoprotein E ε4 allele is a well-established genetic risk factor, AD is increasingly recognized as a polygenic condition. However, how polygenic risk manifests in white matter (WM) microstructure and cognition remains unclear. This study aims to investigate the associations between AD polygenic risk scores (ADPRS), WM microstructure, and cognitive performance in clinically asymptomatic adults.</p><p><strong>Methods: </strong>Data from 36400 individuals (aged 45-83 years) in the UK Biobank were analyzed. Diffusion tensor imaging and neurite orientation dispersion and density imaging metrics were extracted from 48 WM tracts. General linear models were used to examine associations between ADPRS, WM integrity, and 10 cognitive measures. Mediation analyses were conducted to test whether WM microstructure mediated the relationship between ADPRS and cognitive performance.</p><p><strong>Results: </strong>Higher ADPRS was significantly associated with reduced fractional anisotropy and intracellular volume fraction, and with increased mean, axial, and radial diffusivity, as well as isotropic volume fraction across limbic and association fibers, particularly in the cingulum hippocampus, fornix, posterior thalamic radiation, and superior fronto-occipital fasciculus. Higher ADPRS was also associated with poorer cognitive performance, most prominently on tests of executive function (Trail Making Test B), episodic memory (Paired Associate Learning), and processing speed (Symbol Digit Substitution). Mediation analysis revealed that WM microstructural alterations, especially increased radial diffusivity and reduced fractional anisotropy in the posterior thalamic radiation, partially mediated the association between ADPRS and cognitive performance, accounting for up to 4.88% of the total effect.</p><p><strong>Conclusion: </strong>ADPRS is linked to selective WM microstructural alterations and subtle cognitive difference in clinically asymptomatic adults. WM microstructural changes partially mediate the association between ADPRS and cognitive performance.</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":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481157/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146145352","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":"Diagnostic Accuracy of Artificial Intelligence for Predicting MGMT Promoter Methylation in Glioblastoma Using MR Imaging: A Systematic Review.","authors":"Hamza M N Khoursheed, Hamzeh O Qudah, Omar Hossain, Fadi W AlZraikat, Irfan Ullah, Muna T Al-Husban","doi":"10.2463/mrms.rev.2025-0115","DOIUrl":"10.2463/mrms.rev.2025-0115","url":null,"abstract":"<p><strong>Purpose: </strong>Glioblastoma (GBM) is an aggressive brain tumor with poor prognosis. O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation is a critical biomarker for guiding chemotherapy decisions, yet current testing requires invasive tissue sampling. This study aimed to systematically evaluate the diagnostic accuracy of artificial intelligence (AI) models using MRI for non-invasive prediction of MGMT promoter methylation status in GBM.</p><p><strong>Methods: </strong>We conducted a systematic search of PubMed, ScienceDirect, Scopus, Google Scholar, Cochrane, Web of Science and EMBASE, identifying 480 records. After duplicate removal and screening, 14 studies met inclusion criteria. Data extracted included AI model architecture, MRI sequences, segmentation methods, and diagnostic metrics. A bivariate random-effects model was used to pool sensitivity and specificity. Meta-regression analyses assessed the effect of AI model type on diagnostic performance. Study quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.</p><p><strong>Results: </strong>The bivariate random-effects model yielded a pooled sensitivity of 0.536 (95% confidence interval [95% CI]: 0.509-0.563) and a pooled specificity of 0.514 (95% CI: 0.454-0.574), indicating moderate between-study heterogeneity, with an area under the curve of 0.56. The best-performing models included MGMT-net and transformer-based architectures, particularly when using multimodal MRI inputs. Studies employing automated segmentation and single-sequence input (e.g., T2-weighted only) generally demonstrated lower performance. QUADAS-2 assessment indicated a low risk of bias in most domains, with concerns regarding index test thresholds and external validation in some studies.</p><p><strong>Conclusion: </strong>AI-based MRI models show moderate-to-high potential for non-invasive MGMT methylation prediction in GBM. However, heterogeneity in study design, imaging protocols, and validation approaches highlights the need for standardized methodologies and robust external validation before clinical adoption.</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":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13265406/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278108","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":"Prostate Diffusion-weighted Imaging: Selecting the Optimal Repetition Time Using Synthetic Imaging Techniques.","authors":"Atsushi Higaki, Tsutomu Tamada, Mitsuru Takeuchi, Yu Ueda, Yuichi Kojima, Takuma Maruhisa, Hiroyuki Watanabe, Kazunori Moriya, Yoshihiko Fukukura, Akira Yamamoto","doi":"10.2463/mrms.tn.2025-0101","DOIUrl":"10.2463/mrms.tn.2025-0101","url":null,"abstract":"<p><p>The optimal TR for prostate diffusion-weighted imaging (DWI) remains unclear. Given prostate cancers' shorter T1/T2 relaxation times versus benign tissues, TR adjustment may improve contrast. We evaluated 56 clinically significant cancers in 33 patients, comparing synthetic DWI (b-value = 2000 s/mm²) at TR500/1000/1500/2000 ms against conventional TR6000 ms. Assessments included contrast ratio, apparent SNR, lesion conspicuity score, DWI scores based on Prostate Imaging Reporting and Data System (PI-RADS) v2.1, and background suppression. TR6000 showed significantly lower contrast ratio but higher apparent SNR compared with shorter TRs. TR1000-2000 showed higher lesion conspicuity score than TR500, while TR1500-6000 had higher DWI scores than TR500. TR500-1500 provided better background suppression than TR2000/6000. For optimal balance of contrast and noise, TR1000 or TR1500 is recommended for prostate DWI, potentially enhancing prostate cancer detection in clinical practice.</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":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13631412/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145985757","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":"Free-breathing Three-dimensional MR Cholangiopancreatography Using Centric k-space Encoding Improved Gallbladder Visualization: A Prospective Study.","authors":"Junya Tsuzaki, Taiki Nozaki, Daiki Ito, Tetsushi Habe, Sayaka Miyazaki, Manabu Arai, Manabu Hase, Hiroki Sakata, Ryo Tsukada, Yoshitake Yamada, Masahiro Jinzaki","doi":"10.2463/mrms.mp.2025-0149","DOIUrl":"10.2463/mrms.mp.2025-0149","url":null,"abstract":"<p><strong>Purpose: </strong>MR cholangiopancreatography (MRCP) often suffers from signal loss because of concentrated bile. Gradient-and-spin-echo (GRASE) MRCP reduces this effect but is limited by breath-holding. We developed MRCP with centric order encoding (MRCP-CORE), a novel free-breathing sequence with shorter TE using centric k-space trajectory, T2 preparation, and velocity encoding, and evaluated its ability to visualize gallbladder.</p><p><strong>Methods: </strong>In this prospective, single-center study, we enrolled 100 consecutive patients who underwent 3 MRCP sequences (MRCP-CORE, conventional MRCP, and GRASE MRCP) on a 3T system. Two blinded radiologists independently assessed the visibility of anatomical structures, artifacts, and overall image quality. SNR, contrast-to-noise ratio, and contrast ratio of the periductal tissue and gallbladder were measured. The Friedman test was used for comparisons; Jonckheere-Terpstra analysis tested the association between the gallbladder visibility and quantitative metrics.</p><p><strong>Results: </strong>Ninety-nine patients (mean age, 68.5 ± 10.9 years; 52 men, 47 women) were evaluated. MRCP-CORE showed significantly higher SNR than conventional and GRASE MRCP (20.9 vs. 17.3 vs. 15.8; P < 0.001). Gallbladder visibility was significantly higher with MRCP-CORE than via conventional MRCP (P = 0.02) and comparable to that via GRASE MRCP (P = 1.00). No significant differences in artifact and overall image quality were observed among sequences. Trend analysis revealed gallbladder visibility was significantly influenced by bile concentration in conventional MRCP (P < 0.001), but not in MRCP-CORE (P = 0.12) or GRASE MRCP (P = 0.43).</p><p><strong>Conclusion: </strong>MRCP-CORE enhanced gallbladder depiction compared with conventional MRCP, offering a robust free-breathing alternative to breath-hold GRASE MRCP.</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":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13287560/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146145295","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":"Association of Airflow Obstruction and Left Atrial Conduit Strain in Patients with Known or Suspected Coronary Artery Disease.","authors":"Shintaro Yamaguchi, Masaki Ishida, Makiko Kubooka, Masafumi Takafuji, Haruno Ito, Takanori Kokawa, Satoshi Nakamura, Kensuke Domae, Suguru Araki, Yasutaka Ichikawa, Shuichi Murashima, Hajime Sakuma","doi":"10.2463/mrms.mp.2025-0076","DOIUrl":"10.2463/mrms.mp.2025-0076","url":null,"abstract":"<p><strong>Purpose: </strong>Airflow obstruction (AO) and coronary artery disease (CAD) share smoking as a risk factor. They may be associated with alterations in ventricular and atrial volumes and functions, and global coronary flow reserve (CFR), all of which can be assessed by cardiovascular MR (CMR). The purpose of this study was to evaluate the association between AO severity and CMR parameters in patients with known or suspected CAD.</p><p><strong>Methods: </strong>Eighty patients with known or suspected CAD who underwent CMR, including cine, stress and rest perfusion, stress and rest coronary sinus flow measurements by phase-contrast cine, and late gadolinium enhancement; spirometry; and lung CT within 6 months were included in the study. Ventricular and atrial volumes and functions, and global CFR were evaluated by CMR. AO severity was evaluated by the ratio of the forced expiratory volume in the first second to the forced vital capacity (FEV1/FVC). Emphysema severity was determined by Goddard score.</p><p><strong>Results: </strong>Median FEV1/FVC for all patients was 74.8%. Compared with patients with FEV1/FVC above the median, those with FEV1/FVC below the median had more impaired left atrial (LA) reservoir strain (P = 0.010), LA conduit strain (P = 0.012), left ventricular global longitudinal strain (P = 0.025), right atrial reservoir strain (P = 0.028), and Goddard score (P < 0.001). There was no significant difference in global CFR between the groups. Multiple linear regression analysis revealed LA conduit strain and Goddard score as independently associated with FEV1/FVC (β = 0.318, P = 0.001 and β = -0.422, P < 0.001, respectively).</p><p><strong>Conclusion: </strong>LA conduit function was independently associated with FEV1/FVC in patients with known or suspected CAD after adjusting for age, sex, smoking, and the CMR indices. This finding suggests that AO severity is associated primarily with impaired LA conduit function in patients with known or suspected CAD.</p>","PeriodicalId":94126,"journal":{"name":"Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine","volume":"25 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13287918/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147577461","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":"Fast MR Simulation Using Combined Update of Grouped Isochromats.","authors":"Hidenori Takeshima","doi":"10.2463/mrms.mp.2025-0131","DOIUrl":"10.2463/mrms.mp.2025-0131","url":null,"abstract":"<p><strong>Purpose: </strong>This work aims to overcome an assumption of conventional MR simulators: Individual isochromats should be simulated individually.</p><p><strong>Methods: </strong>To reduce the computational times of MR simulation, a new simulation method using grouped isochromats is proposed. When multiple isochromats are grouped before simulations, some parts of the simulation can be shared in each group. For a certain gradient type, the isochromats in the group can be easily chosen for ensuring that they behave the same. For example, the group can be defined as the isochromats whose locations along x-axis, T1, T2 and magnetic field inhomogeneity values are the same values. In such groups, simulations can be combined when a pulse sequence with the magnetic field gradient along x-axis only are processed. The processing times of the conventional and proposed methods were evaluated with several sequences including echo-planar imaging (EPI) and spiral sequences.</p><p><strong>Results: </strong>The simulation times of the proposed method were 1.7 to 161 times faster than those of the conventional methods. In the cases of 2.3 billion isochromats using single instruction, multiple data (SIMD) instructions and multi-threading, the conventional method simulated the EPI and spiral sequences in 5526.7 and 15678.4 seconds, respectively. In the same cases, the proposed method simulated these sequences in 652.2 and 8046.2 seconds, respectively.</p><p><strong>Conclusion: </strong>The proposed method using grouped isochromats was efficient for reducing the computational times of the simulations.</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":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13503010/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147328764","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":"Recent Advances in Musculoskeletal Radiology: Bridging Innovation and Clinical Application.","authors":"Satoru Ide, Takatoshi Aoki, Ryo Kurokawa, Masahiro Yanagawa, Tsukasa Saida, Shunsuke Sugawara, Kentaro Nishioka, Seitaro Oda, Tadashi Watabe, Kenji Hirata, Rintaro Ito, Daiju Ueda, Koji Takumi, Maya Honda, Akihiko Sakata, Mariko Kawamura, Keitaro Sofue, Mami Iima, Shinji Naganawa","doi":"10.2463/mrms.rev.2025-0150","DOIUrl":"10.2463/mrms.rev.2025-0150","url":null,"abstract":"<p><p>Recent advances in musculoskeletal (MSK) radiology have markedly improved diagnostic accuracy through innovations in MRI, CT, and artificial intelligence (AI). This review summarizes 7 key domains shaping current MSK imaging: (1) CT-like contrast MRI techniques for bone visualization, (2) quantitative MRI approaches, (3) AI applications in image reconstruction and diagnostic support, (4) MR spectroscopy (MRS) for metabolic assessment, (5) whole-body MRI for systemic disease evaluation, (6) positron emission tomography (PET) for metabolic and inflammatory imaging, and (7) advanced CT techniques such as weight-bearing CT. Zero echo time and ultrashort echo time MRI sequences enable the visualization and quantitative assessment of short-T2 tissues such as cortical bone, tendons, and fibrocartilage. Deep learning-based image reconstruction improves SNR and shortens scan time, enhancing image quality and diagnostic confidence. In parallel, AI-driven diagnostic support systems, including convolutional neural networks for lesion detection and natural language processing for report generation, are transforming workflow efficiency and consistency. MRS offers metabolic insights into muscle disorders such as sarcopenia, and whole-body-MRI provides comprehensive, radiation-free evaluation of tumor burden and inflammatory joint or enthesis involvement, making it valuable in oncology and rheumatic diseases. PET complements MRI by identifying metabolically active or inflammatory lesions. CT-based innovations further contribute to evaluating joint biomechanics with high spatial resolution. Together, these technological developments are enabling earlier disease detection, more precise diagnosis, and improved treatment monitoring, representing a paradigm shift in MSK imaging and clinical practice.</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":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13253065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145829414","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":"Enhanced Visualization of Intracranial Cortical Arteries Using Deep Learning Reconstruction in Vessel Wall MR Imaging.","authors":"Satoru Ide, Koichiro Futatsuya, Yuta Yoshimatsu, Toshihiro Sakamoto, Kazuhiro Kajio, Hirotaka Inoue, Naoki Ogawa, Yu Murakami, Takatoshi Aoki","doi":"10.2463/mrms.tn.2025-0091","DOIUrl":"10.2463/mrms.tn.2025-0091","url":null,"abstract":"<p><p>This study evaluated the utility of deep learning reconstruction (DLR) in vessel wall imaging (VWI) for visualizing the entire cerebral arterial system, including cortical arteries. Seventeen patients underwent post-contrast 3D T1WI-CUBE VWI with 0.5 mm isotropic resolution. Images with and without DLR were compared using qualitative and quantitative assessments. Qualitative image quality was rated on a 4-point scale across 29 arterial segments, including the internal carotid, vertebral, basilar, and the 1st to 4th segments of the major cerebral arteries. Quantitative evaluation of the vertebral artery wall assessed SNR and contrast-to-noise ratio (CNR). DLR significantly improved overall image quality compared to the without-DLR group, with cortical arteries rated as optimal in all cases with DLR (all P < 0.001). SNR and CNR were also significantly higher with DLR (P = 0.004). These results suggest that DLR enables high-resolution VWI of intracranial cortical arteries within a clinically acceptable scan time.</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":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13250456/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145598519","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":"Quality of Head and Neck Diffusion-weighted MR Imaging Using a Combination of the Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) Sequence and Deep Learning Reconstruction.","authors":"Taro Fujiwara, Noriyuki Fujima, Hiroyuki Hamaguchi, Kinya Ishizaka, Kohsuke Kudo","doi":"10.2463/mrms.mp.2025-0058","DOIUrl":"10.2463/mrms.mp.2025-0058","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate whether periodically rotated overlapping parallel lines with enhanced reconstruction-diffusion-weighted imaging (PROPELLER-DWI) combined with deep learning-based reconstruction (DLR) improves head and neck DWI, we conducted a primary comparison of PROPELLER-DWI with DLR at varying strengths and without DLR, and a secondary comparison of DLR-processed PROPELLER-DWI with DLR-processed single-shot echo-planar imaging (EPI)-DWI.</p><p><strong>Methods: </strong>Ten healthy adults (8 males, 2 females) participated in the study. PROPELLER-DWI and single-shot EPI-DWI images were acquired using a 3-Tesla MRI system (Discovery MR750w; GE Healthcare, Waukesha, WI, USA) with various recon deep-learning strength (DLS) values: off (DLS-Off), low (DLS-L), medium (DLS-M), and high (DLS-H). We measured the SNR and contrast ratio on DWI images and value of coefficient of variation (CV) on apparent diffusion coefficient (ADC) maps for a quantitative evaluation. For a qualitative evaluation, we visually evaluated the overall image quality, degree of geometric distortion, and magnetic susceptibility artifacts.</p><p><strong>Results: </strong>The SNRs for PROPELLER and EPI-DWI improved with the increase in the DLS level, with DLS-H showing a significantly higher SNR than DLS-Off. ADC maps demonstrated lower CVs at higher DLS levels, significantly lower in DLS-H than DLS-Off. The qualitative evaluation revealed that PROPELLER-DWI with DLR (at all DLS levels: -L, -M, and -H) provided significantly better overall image quality than that without DLR. In addition, PROPELLER-DWI demonstrated significantly higher qualitative scores across all evaluation items (i.e., overall image quality, geometric distortion, and magnetic susceptibility artifacts) compared with EPI-DWI.</p><p><strong>Conclusion: </strong>In head and neck DWI, PROPELLER-based acquisition with DLR enabled the acquisition of visually superior image quality. This approach is clinically useful for the head and neck radiology.</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":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13219838/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000275","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":"Utility of Locus Coeruleus Signal Intensity on High-resolution T1-weighted MR Imaging with Magnetization Transfer for Differentiating Parkinson's Disease from Atypical Parkinsonism.","authors":"Yuta Yoshimatsu, Satoru Ide, Naoki Ogawa, Kazuhiro Kajio, Toshihiro Sakamoto, Koichiro Futatsuya, Yu Murakami, Tomoyo Hashimoto, Hiroaki Adachi, Takatoshi Aoki","doi":"10.2463/mrms.mp.2025-0126","DOIUrl":"10.2463/mrms.mp.2025-0126","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to evaluate the diagnostic utility of locus coeruleus (LC) signal intensity on high-resolution T1-weighted imaging with magnetization transfer (T1WI with MT) for distinguishing Parkinson's disease (PD) from a broad range of atypical parkinsonism (AP) subtypes, including early-stage cases.</p><p><strong>Methods: </strong>We retrospectively analyzed T1WI with MT data from 214 participants, including patients with PD (n = 125), corticobasal syndrome (CBS, n = 12), multiple system atrophy (MSA, n = 16), progressive supranuclear palsy (PSP, n = 19), essential tremor (n = 17), vascular parkinsonism (n = 4), drug-induced parkinsonism (DIP, n = 7), and healthy subjects (HS, n = 14). Circular ROIs were placed on the LC and substantia nigra pars compacta to calculate contrast ratios (CRs). Conventional MRI findings of AP, focusing on characteristic regional atrophy patterns, were also evaluated. Diagnostic performance was assessed using receiver operating characteristic (ROC) analysis. A subanalysis was performed for early-stage cases (within 2 years of onset). Three independent neuroradiologists evaluated T1WI with MT, and interobserver agreement was assessed using intraclass correlation coefficients (ICC).</p><p><strong>Results: </strong>The LC-CR was significantly lower in PD than in HS (P < 0.01) and all AP subtypes except DIP (P = 0.37). ROC analysis revealed that LC-CR had the highest diagnostic accuracy for differentiating PD from AP (area under the curve [AUC] = 0.83, sensitivity = 67%, specificity = 90%). In early-stage cases, LC-CR maintained high specificity (98%) with an AUC of 0.80. The diagnostic utility of LC-CR was comparable or superior to conventional MRI findings in distinguishing PD from CBS, MSA, and PSP. Interobserver agreement for LC-CR measurements was good, with an ICC of 0.87 (95% confidence interval: 0.85-0.89).</p><p><strong>Conclusion: </strong>LC-CR measured on T1WI with MT serves as a reliable imaging biomarker for differentiating PD from various forms of AP, even in early disease stages.</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":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13218839/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145440256","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}