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

{"title":"Evaluation of Articular Cartilage in Knee Osteoarthritis Using Macromolecular Proton Fraction Mapping.","authors":"Mio Ariki, Yasuhiro Fujiwara, Motohira Mio, Kosuke Yamashita, Mika Kitajima","doi":"10.2463/mrms.mp.2025-0053","DOIUrl":"10.2463/mrms.mp.2025-0053","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the clinical utility of macromolecular proton fraction mapping for early osteoarthritis detection and compare its effectiveness with T₂* mapping in evaluating cartilage degeneration.</p><p><strong>Methods: </strong>Eleven controls and 29 patients with osteoarthritis underwent 3.0T magnetic resonance imaging. Patients were classified based on the Kellgren-Lawrence grading system into mild osteoarthritis (KL 1-2, n = 9) and severe (KL 3-4, n = 20) osteoarthritis. Macromolecular proton fraction maps were generated from proton density-, T₁-, and magnetization transfer-weighted images using a single-point synthetic reference algorithm. T₂* maps were derived from multi-echo sequences. Macromolecular proton fractions and T₂* values were measured in 6 subregions of the femoral cartilage. Statistical analyses were conducted to compare values among the control, mild osteoarthritis, and severe osteoarthritis groups.</p><p><strong>Results: </strong>Macromolecular proton fraction values decreased with increasing osteoarthritis severity. Compared to controls, both the mild and severe osteoarthritis groups exhibited significantly lower macromolecular proton fraction in the medial anterior and medial posterior regions. Additionally, the severe osteoarthritis group demonstrated significantly lower macromolecular proton fraction values in the medial central and lateral posterior regions compared to controls. In contrast, T₂* values generally increased with osteoarthritis severity. The mild and severe osteoarthritis groups had significantly elevated T₂* values in the medial anterior region compared to controls. Furthermore, the mild osteoarthritis group exhibited increased T₂* in the medial central region, whereas the severe osteoarthritis group had significantly higher T₂* in the medial anterior, medial posterior, and lateral posterior regions compared to controls.</p><p><strong>Conclusion: </strong>Macromolecular proton fraction mapping demonstrated sensitivity to early-stage cartilage degeneration in osteoarthritis, suggesting its potential as a biomarker for early osteoarthritis detection. The combination of macromolecular proton fraction and T₂* mapping could enhance the biochemical assessment of cartilage integrity, providing valuable insights for early diagnosis and monitoring treatment effects in osteoarthritis.</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/PMC13217289/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145351136","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 Modified Look-Locker Inversion Recovery Sampling Scheme on Accuracy and Heart Rate Variability in Myocardial T1 Mapping.","authors":"Yuta Endo, Keita Fukushima, Akihito Nakanishi, Kenichi Yokoyama","doi":"10.2463/mrms.tn.2025-0022","DOIUrl":"10.2463/mrms.tn.2025-0022","url":null,"abstract":"<p><p>This study aimed to clarify the accuracy and variability of heart rate variability effects on T1 relaxation time values acquired using different sampling schemes of the modified Look-Locker inversion recovery (MOLLI) method. Five MOLLI sampling schemes-5(3)3, 5s(3s)3s, 4(1)3(1)2, 4s(1s)3s(1s)2s, and 3(3)3(3)5-were compared using a simulated electrocardiogram signal in a phantom experiment. The 5(3)3 and 5s(3s)3s schemes demonstrated high accuracy across the range of native and contrast-enhanced T1 values, with correlation coefficients exceeding 0.95 compared with the reference T1. Regarding heart rate variability, the 5(3)3 scheme showed minimal variation in the measured value across different heart rates, regardless of the T1 value, with an error rate below 6% relative to the reference T1. Therefore, the 5(3)3 scheme can achieve highly accurate measurements over a wide T1 range and is robust against heart rate variability.</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/PMC13247636/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145535194","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":"Associations between MR Imaging-derived Metrics under Exercise Load, Wingate Test Results, and Sprint Performance.","authors":"Shuhei Shibukawa, Takuya Ozawa, Kaito Takabayashi, Koyo Mizuta, Wataru Uchida, Ko Yamanaka, Jimmy Kim, Kazuhiko Yamazaki, Takafumi Iwasaki, Nobuaki Mizuguchi, Akifumi Hagiwara, Moto Nakaya, Masaya Takahashi, Hidefumi Waki, Shigeki Aoki, Koji Kamagata","doi":"10.2463/mrms.mp.2025-0122","DOIUrl":"10.2463/mrms.mp.2025-0122","url":null,"abstract":"<p><strong>Purpose: </strong>The primary objective of this study was to determine the relationship between Wingate test, athletic performance, and MRI parameters in athletes. Additionally, we examined whether there were significant differences in these parameters between athletes and non-athletes during dorsiflexion exercises.</p><p><strong>Methods: </strong>Twenty-two male athletes and 9 non-athletes performed dorsiflexion exercises with a 4-kg load. MRI scans, including T2* mapping and diffusion tensor imaging, were conducted pre-exercise, immediately after exercise, and 30 minutes post-exercise. Quantitative parameters, including T2* values, fractional anisotropy, mean diffusivity, and eigenvalues (λ2, λ3), were analyzed. Wingate test results and athletics scoring based on the 2022 World Athletics Scoring Tables were used to evaluate anaerobic power and sprint performance.</p><p><strong>Results: </strong>MRI parameters, particularly T2* changes and λ3, showed significant correlations with Wingate test results and athletic performance. Pre-exercise λ3, reflecting muscle fiber orientation and thickness, emerged as a key predictor of athletic performance alongside T2* changes and Wingate power. The integration of MRI-derived metrics with Wingate test results improved the prediction of athletic scores compared to Wingate power alone. Although differences between athletes and non-athletes in T2* and λ2 were observed, these findings serve as supplementary evidence supporting the role of MRI in identifying muscle characteristics critical for athletic performance.</p><p><strong>Conclusion: </strong>MRI-derived parameters combined with performance tests can provide valuable insights into muscle recovery, structure, and athletic performance, with potential for predicting athlete scores and optimizing training strategies.</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/PMC13219962/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145919504","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":"MoRE-Net: An Interpretable and Modality-robust Model for Brain Tumor Grading.","authors":"Binghua Li, Chao Li, Wataru Uchida, Toshihisa Tanaka, Qibin Zhao, Shigeki Aoki, Zhe Sun","doi":"10.2463/mrms.mp.2025-0107","DOIUrl":"10.2463/mrms.mp.2025-0107","url":null,"abstract":"<p><strong>Purpose: </strong>Interpretability and robustness are both critical for developing trustworthy artificial intelligence, especially in high-stakes domains such as medical diagnosis. However, few studies have explored how to enhance robustness within interpretable model frameworks. This work aims to improve the robustness of interpretable multimodal medical imaging diagnostic models, particularly under missing modality conditions.</p><p><strong>Methods: </strong>We propose the Modality-Robust and Explainable Network (MoRE-Net), a robust and interpretable model for brain tumor grading. Built on a variant of the interpretable prototypical part network, MoRE-Net uses independent per-modality encoders to extract modality-specific features. To address the absence of inter-modality interactions, we introduce 2 key designs: (1) Mamba-based per-modality encoders for efficient global-context modeling; and (2) an online multimodal teacher that guides the per-modality encoders via an alignment loss during early training, which is gradually annealed and removed. We evaluate MoRE-Net on 369 subjects with multimodal MRI from the BraTS2020 dataset, using balanced accuracy (BAC) for grading performance and activation precision (AP) for interpretability. We further validate the model on the real-world ReMIND dataset.</p><p><strong>Results: </strong>MoRE-Net achieves an average BAC of 73.5% and AP of 61.2% across all missing modality scenarios on BraTS2020 dataset, surpassing baseline methods by about 15% and 21%, respectively. Results on ReMIND dataset and ablation studies confirm its effectiveness of each proposed strategy and the overall robustness.</p><p><strong>Conclusion: </strong>We introduce MoRE-Net, a novel interpretable and modality-robust model for brain tumor grading. Experimental results demonstrate its strong performance in both diagnostic accuracy and interpretability under missing modality conditions, indicating its potential for clinical deployment.</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/PMC13247638/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146168424","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":"Short-TR Acquisition Time-of-flight MR Angiography with Deep Learning Reconstruction: Technical Feasibility and Initial Clinical Evaluation in Moyamoya Disease.","authors":"Naoyuki Takei, Keita Fujii, Xucheng Zhu, Shohei Inui, Naoya Sakamoto, Yuichi Suzuki, Tetsuya Wakayama, Shiori Amemiya, Osamu Abe","doi":"10.2463/mrms.mp.2025-0139","DOIUrl":"10.2463/mrms.mp.2025-0139","url":null,"abstract":"<p><strong>Purpose: </strong>To develop and evaluate short-TR acquisition time-of-flight (STRA-TOF) MR angiography (MRA), which combines an optimized STRA with deep learning-based reconstruction to achieve scan-time reduction while maintaining image quality in the visualization of intracranial arteries.</p><p><strong>Methods: </strong>Ten healthy volunteers and 3 patients with moyamoya disease were examined using 3D TOF MRA with the clinical moyamoya protocol and 2 STRA-TOF protocols employing 4-slab (STRA4) and 9-slab (STRA9) configurations. STRA-TOF employed a TR of approximately 10 ms with variable-density Poisson-disc sampling and unrolled deep learning reconstruction. Bloch equation simulations validated the theoretical basis for STRA. Quantitative assessment included SNR and contrast-to-noise ratio measurements. Two radiologists independently evaluated image quality using a 3-point scale across 9 vascular territories and overall image quality, with blinded assessment. Statistical analysis was performed using the Friedman test with post hoc Wilcoxon signed-rank tests.</p><p><strong>Results: </strong>STRA-TOF achieved approximately a 50% reduction in scan time compared with conventional protocols. Both STRA sequences demonstrated significantly higher SNR and contrast-to-noise ratio than conventional TOF (P < 0.001). Overall image quality scores were higher for STRA4 and STRA9 compared with conventional TOF in both readers. Across the 9 vascular territories, both readers consistently rated STRA sequences equal to or superior to conventional TOF, particularly for distal branches. In the small patient cohort with moyamoya disease (n = 3), STRA-TOF demonstrated feasibility for visualizing complex arterial pathology, including stenotic vessels, collateral circulation, and postsurgical vascular changes.</p><p><strong>Conclusion: </strong>STRA-TOF achieved approximately a 50% reduction in scan time while maintaining or improving image quality compared with conventional 3D TOF MRA. This technique addresses the fundamental scan-time limitations of the conventional method, with potential for significant clinical benefits in terms of patient comfort, workflow efficiency, and improved access to intracranial artery evaluation.</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/PMC13219747/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145985793","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":"Optimal Number of Signal Averages in Stimulated Echo Acquisition Mode for Proton MR Spectroscopy of Brain at 7T.","authors":"Tsuyoshi Matsuda, Futoshi Mori, Manami Akasaka, Ryoichi Tanaka, Makoto Sasaki","doi":"10.2463/mrms.tn.2025-0123","DOIUrl":"10.2463/mrms.tn.2025-0123","url":null,"abstract":"<p><p>We have developed a practical method to determine the optimal number of signal averages (NSAs) for acquiring a spectrum in the human brain and determined the optimal number of NSA at 7-Tesla. We performed 50 sequential data acquisitions with an NSA of 2 in healthy volunteers and then generated spectra with NSAs ranging from 2 to 100. After identifying the metabolites with Cramér-Rao lower bounds (CRLB) ≤ 15% in the NSA 100 spectrum, we examined the CRLB values, creatine+phosphocreatine (Cr + PCr) ratios and agreement of Cr + PCr ratios. Eight metabolites and 5 metabolite pairs spectrum showed CRLB values ≤ 15% when the NSA was 40 or higher. Additionally, the Cr + PCr ratios at NSA 40 closely matched those at NSA 100. By analyzing the CRLB values of metabolites in varying NSAs spectra generated from sequential data, we determined the optimal NSA needed to accurately measure the spectrum within a reasonable acquisition 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/PMC13247735/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145758844","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":"Evaluation of Approved AI-based Brain Aneurysm Detection Software in Clinical Practice: Comparison with Radiologist Assessment and Image Re-review.","authors":"Rintaro Ito, Ryota Asai, Rei Nakamichi, Toshiki Nakane, Toshiaki Taoka, Shinji Naganawa","doi":"10.2463/mrms.mp.2024-0183","DOIUrl":"10.2463/mrms.mp.2024-0183","url":null,"abstract":"<p><strong>Purpose: </strong>This study evaluated the performance of artificial intelligence (AI)-based brain aneurysm detection software in clinical settings, aiming to assess its utility as a supportive tool for radiologists. Metrics included sensitivity, positive predictive value (PPV), F1 score, and false positives (FPs) per case.</p><p><strong>Methods: </strong>A retrospective analysis of 442 cases (March 2023-August 2024) compared AI detections against a reference standard derived from the radiologists' assessments and image re-review. Findings were categorized into true positives (TPs), FPs, and false negatives (FNs). Subgroup analyses covered aneurysm size, magnetic field strength of the MRI, patient age, and aneurysm location.</p><p><strong>Results: </strong>The study included 442 cases (226 males, 216 females; median age 72). Out of 94 total aneurysms, the AI detected 73 TP and missed 21 FN. It also identified 520 FP. Overall, sensitivity was 77.7%, PPV was 12.3%, and the F1 score was 0.212. The FPs averaged 1.18 per case. Sensitivity varied by aneurysm size: 85.1% for ≤ 3 mm, 69.2% for 3-5 mm, and 50.0% for > 5 mm. Significant variability in FPs per case was observed across different magnetic field strengths. Performance also varied by patient age and aneurysm location.</p><p><strong>Conclusion: </strong>The AI software demonstrated moderate sensitivity, especially for smaller aneurysms. Variations in performance across different magnetic field strengths and aneurysm size suggest a need for more robust AI algorithms. Detailed analysis of aneurysm locations provides insights into areas where AI performance could be enhanced. Integrating the AI software as a supportive tool, combined with radiologist expertise, is hypothesized to enhance detection accuracy, though further studies are needed to quantify this combined effect.</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/PMC13219226/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145453859","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":"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":"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":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13041251/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145034987","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":"Labyrinthine Signal Intensity on Non-contrast-enhanced 3D-real Inversion Recovery MR Imaging: Correlation with the Endolymphatic Volume Measured on Contrast-enhanced HYDROPS-Mi2.","authors":"Toshio Ohashi, Shinji Naganawa, Ryo Yamamoto, Kayao Kuno","doi":"10.2463/mrms.mp.2025-0068","DOIUrl":"10.2463/mrms.mp.2025-0068","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the relationship between the signal intensity (SI) of the entire labyrinthine fluid on non-contrast-enhanced 3D real inversion recovery (3D-real IR) imaging and the endolymphatic volume measured on contrast-enhanced HYDROPS-Mi2 (HYbriD of Reversed image Of Positive endolymph signal and native image of positive perilymph Signal image Multiplied with hT2w MR cisternography) imaging.</p><p><strong>Methods: </strong>This retrospective study included 37 patients (74 ears) with suspected endolymphatic hydrops (EH). The volume ratio of the endolymphatic space (%EL_vol) was measured on contrast-enhanced HYDROPS-Mi2 images, and the normalized volume-averaged signal intensity (nSI_vol) of the entire labyrinthine fluid was measured on non-contrast-enhanced 3D-real IR images. Statistical analyses included comparisons of nSI_vol between the cochlea and vestibule, side-to-side differences in EH-negative ears, paired comparisons of nSI_vol between larger- and smaller-%EL_vol sides, correlations between %EL_vol and nSI_vol, and receiver operating characteristic (ROC) curve analysis of nSI_vol for discriminating severe from mild/no EH. The presence of EH was defined based on the clinical diagnosis using Nakashima grading.</p><p><strong>Results: </strong>The vestibular %EL_vol was significantly higher and the vestibular nSI_vol significantly lower than that in the cochlea (both P < 0.001). In EH-negative ears, no significant side-to-side difference in nSI_vol was observed. In both cochleae and vestibules, nSI_vol was significantly lower on the larger-%EL_vol side than on the smaller-%EL_vol side (cochlea: P = 0.002; vestibule: P = 0.007). Significant negative correlations between %EL_vol and nSI_vol were observed in both the cochlea (Spearman's rank correlation coefficient [R_s] = -0.598, P < 0.001) and vestibule (R_s = -0.417, P < 0.001). The area under the ROC curve was 0.827 in the cochlea, and 0.698 in the vestibule.</p><p><strong>Conclusion: </strong>The SI of the entire labyrinthine fluid measured on non-contrast-enhanced 3D-real IR imaging showed a significant negative correlation with the endolymphatic volume measured on contrast-enhanced HYDROPS-Mi2. These findings suggest that the SI of labyrinthine fluid, as measured on non-contrast-enhanced 3D-real IR images, may serve as an indirect indicator for estimating the degree of EH.</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":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13041244/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145287927","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 Potential of Macromolecular Proton Fraction Mapping Combined with Quantitative Susceptibility Mapping as a Subcortical Biomarker for Parkinson's Disease.","authors":"Yasuhiro Fujiwara, Nobutaka Sakae, Hiroyuki Kumazoe, Kouta Miyamoto, Yoshinori Hirakawa, Hirohito Kan, Kosuke Yamashita, Mika Kitajima","doi":"10.2463/mrms.mp.2025-0045","DOIUrl":"10.2463/mrms.mp.2025-0045","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to evaluate the diagnostic potential of macromolecular proton fraction (MPF) mapping combined with magnetic susceptibility measurements as subcortical biomarkers in Parkinson's disease (PD).</p><p><strong>Methods: </strong>Twenty patients with PD and 9 age-matched healthy controls underwent 3.0T magnetic resonance imaging, including MPF mapping and quantitative susceptibility mapping (QSM). MPF and magnetic susceptibility values of the 16 subcortical nuclei were measured in both the PD group and healthy control group, and these values were compared between the 2 groups. Diagnostic performance of MPF and magnetic susceptibility in the subcortical nuclei was individually evaluated using receiver operating characteristic (ROC) analysis. A logistic regression model was developed for the diagnosis of PD using a combination of MPF and magnetic susceptibility values.</p><p><strong>Results: </strong>Quantitative analyses revealed significantly reduced MPF values (false discovery rate-corrected P < 0.05) in 7 subcortical nuclei in the PD group, namely the hypothalamus, parabrachial pigmented nucleus, red nucleus, substantia nigra pars reticulata, substantia nigra pars compacta, ventral pallidum, and ventral tegmental area. Additionally, magnetic susceptibility was significantly elevated (false discovery rate-corrected P < 0.05) in the parabrachial pigmented nucleus and substantia nigra pars compacta. ROC curve analysis demonstrated strong diagnostic performance, with the ventral pallidum showing the highest MPF-based diagnostic accuracy (area under the curve [AUC] = 0.82) and the substantia nigra pars compacta showing the highest QSM-based accuracy (AUC = 0.88). The logistic regression model combining MPF and magnetic susceptibility showed the best performance (AUC = 0.93).</p><p><strong>Conclusion: </strong>MPF mapping, particularly when combined with magnetic susceptibility measurements, may serve as a quantitative diagnostic biomarker for PD, and the observed widespread alterations across multiple subcortical nuclei provide new insights into the pathology of PD beyond the classic nigrostriatal pathway.</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":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13041249/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145254229","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}