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

{"title":"Impact of Free Water Correction on the Mean Diffusivity of Glioblastoma is Regional and b-value Dependent: A Retrospective Study on Open-source Datasets.","authors":"Shu Matsushita, Hiroyuki Tatekawa, Daisuke Horiuchi, Tatsushi Oura, Natsuko Atsukawa, Ayako Omori, Hirotaka Takita, Taro Shimono, Daiju Ueda, Yukio Miki","doi":"10.2463/mrms.mp.2026-0019","DOIUrl":"10.2463/mrms.mp.2026-0019","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the effects of free-water (FW) correction on mean diffusivity (MD) values in glioblastomas using diffusion tensor imaging (DTI) with different b-value settings. We also examined regional differences between contrast-enhanced (CE) tumor and peritumoral fluid-attenuated inversion recovery (FLAIR) hyperintense regions.</p><p><strong>Methods: </strong>DTI data from 787 participants with glioblastoma were obtained from 2 open-source datasets: the University of California, San Francisco Preoperative Diffuse Glioma MRI (UCSF-PDGM; b-value, 2000) and the Multi-parametric Magnetic Resonance Imaging Scans for De Novo Glioblastoma Patients from the University of Pennsylvania Health System (UPENN-GBM; b-value, 1000). Conventional and FW-corrected MD maps were generated, and median MD values were calculated from CE and FLAIR hyperintense regions. The impact of FW correction was assessed via the Wilcoxon matched-pairs signed rank test, Bland-Altman plot, and Spearman's correlation analysis. Multivariate Cox regression was used to evaluate prognostic significance, adjusting for age and CE volume.</p><p><strong>Results: </strong>Both median MD values were significantly lower in the CE regions than in the FLAIR hyperintense regions. In the UCSF-PDGM dataset, FW correction caused a greater reduction of MD in the CE regions, whereas the greater reduction occurred in the FLAIR hyperintense regions in the UPENN-GBM dataset. Bland-Altman plot also indicated lesions with lower MD values showing greater FW correction in the UCSF-PDGM dataset, whereas those with relatively high MD values showed greater FW correction in the UPENN-GBM dataset. The correlation between both MD values was high (Rs > 0.98). Neither conventional MD nor FW-corrected MD values in the CE regions were significantly associated with overall survival. (Ps > 0.30).</p><p><strong>Conclusion: </strong>A paradoxical relationship of MD values with and without FW correction was identified depending on regional characteristics and b-value settings, underscoring the importance of acquisition parameters when interpreting FW correction.</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":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13522939/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148254949","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":"Measuring Brain Stiffness in Normal Adults According to Age and Sex Using Virtual MR Elastography: A Preliminary Study.","authors":"Jung Hyun Park, Miran Han, Miseon Yeon, Jin Wook Choi","doi":"10.2463/mrms.mp.2025-0040","DOIUrl":"10.2463/mrms.mp.2025-0040","url":null,"abstract":"<p><strong>Purpose: </strong>Assessing brain stiffness alterations associated with normal aging, sex-related differences, and regional variations is important from clinical perspective. The study aimed to investigate the changes in brain stiffness according to age and sex using virtual magnetic resonance elastography (vMRE), a noninvasive and novel technique based on diffusion-weighted imaging (DWI).</p><p><strong>Methods: </strong>We retrospectively reviewed 96 adults (31-80   years, 51 men and 45 women) who underwent MRI as part of routine medical examinations. The shifted apparent diffusion coefficient was calculated from DWI (b   =   200 and 1500   sec/mm²) and converted to the DWI-based virtual shear modulus (μ_diff). Brain stiffness was measured in 12 brain regions: the cerebrum, cerebral gray/white matter, basal ganglia, thalamus, frontal lobe, parietal lobe, temporal lobe, occipital lobe, cerebellum, hippocampus, and amygdala. Linear regression and multiple-comparison tests were performed to evaluate the effects of age and regional differences.</p><p><strong>Results: </strong>Brain stiffness exhibited regional differences, with higher shear modulus values observed in deep structures (thalamus and basal ganglia) compared to that in lobar regions (P   <   0.01). Among lobar areas, the occipital lobe had the highest stiffness, whereas the temporal lobe had the lowest (P   <   0.01). Linear regression revealed a significant negative correlation between age and brain stiffness (-0.06%/year, R²   =   0.09, P   =   0.04). The most pronounced decline in elasticity (-0.28%/year, R²   =   0.66, P   <   0.01) was observed in cerebral gray matter. Hippocampal stiffness significantly decreased after the fifth decade of life. Sex-related differences were found only in the parietal lobe (P   =   0.02) and basal ganglia (P   =   0.03).</p><p><strong>Conclusion: </strong>Our findings suggest that vMRE can effectively measure the elastic properties of the brain. Brain stiffness decreases with age, but these changes vary across different regions.</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":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13519801/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148159600","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":"A Novel MR Cine Sialography Technique for Evaluating Salivary Gland Function: Correlation with Unstimulated and Stimulated Saliva Volumes.","authors":"Tatsuya Koizumi, Masami Goto, Yosuke Kogure, Hideo Kawasaki, Toru Nagasawa, Noboru Hojo, Naoko Saito, Shinsuke Kyogoku, Ryohei Kuwatsuru","doi":"10.2463/mrms.mp.2026-0004","DOIUrl":"10.2463/mrms.mp.2026-0004","url":null,"abstract":"<p><strong>Purpose: </strong>This study evaluated salivary gland function using MR cine sialography (MRCS) based on the time-spatial labeling inversion pulse (Time-SLIP) technique combined with a deep learning reconstruction-based denoising method (dDLR). Bilateral salivary flow from the submandibular glands (SMGs) and parotid glands (PGs) was visualized, and its correlation with whole-saliva volume was examined.</p><p><strong>Methods: </strong>Optimal MRCS parameters were identified, and imaging was performed in 11 healthy volunteers. Correlations between salivary flow on MRCS and unstimulated whole-saliva volume (UWS) and stimulated whole-saliva volume (SWS), as well as side-to-side differences, were analyzed. UWS was obtained using the spitting method, and SWS was obtained using the gum-chewing test. Salivary-flow distance was defined as the length from the labeling position to the point where the labeled saliva signal became indistinguishable from background signal. Spearman's rank correlation coefficients (ρ) were calculated to evaluate the association between whole-saliva volume and MRCS, and Wilcoxon's signed-rank test was used to assess side-to-side differences.</p><p><strong>Results: </strong>Correlation coefficients between MRCS and whole-saliva volume were as follows: under unstimulated conditions, SMG ρ = 0.825, PG ρ = -0.05, SMG + PG ρ = 0.802; under stimulated conditions, SMG ρ = 0.606, PG ρ = 0.72, and SMG + PG ρ = 0.820. Strong correlations (ρ > 0.8) were observed for SMG and SMG + PG under unstimulated conditions and for SMG + PG under stimulation. No significant overall side-to-side differences were found except for PG under stimulation (P = 0.016). However, several individuals showed notable side-to-side differences, underscoring the value of bilateral imaging.</p><p><strong>Conclusion: </strong>Bilateral SMG and PG salivary flows obtained using MRCS with dDLR showed strong correlations with UWS and SWS. These findings suggest that MRCS is a promising noninvasive method for assessing salivary volume and supports both separate and combined evaluation of SMG and PG function.</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":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13500222/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936558","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":"Improvement in Image Quality and Efficiency of Non-contrast Thoracic MR Angiography: Comparison of a Highly Accelerated Dixon-based Technique with the Conventional Fat-suppressed Technique.","authors":"Jingyi Xing, Satoshi Higuchi, Ryuichi Mori, Yuki Ichinoseki, Yoshiaki Komori, Akihiro Manabe, Daniel Giese, Michaela Schmidt, Hiroki Kamada, Hidenobu Takagi, Kei Takase, Hideki Ota","doi":"10.2463/mrms.mp.2025-0164","DOIUrl":"10.2463/mrms.mp.2025-0164","url":null,"abstract":"<p><strong>Purpose: </strong>To compare the image quality and acquisition time of thoracic great vessels using a novel, 3D isotropic non-contrast-enhanced MR angiography that combines respiratory compensation, electrocardiogram-triggering, compressed sensing, and Dixon water-fat separation at 3T (CS-MRA) to a conventional MRA employing parallel imaging and spectral attenuated inversion recovery (cMRA).</p><p><strong>Methods: </strong>This study included 20 healthy volunteers and 19 patients with thoracic vascular diseases. All scans were performed on a 3T MRI scanner using a T2-prepared 3D fast low angle shot (FLASH) sequence. Visual image quality of thoracic great vessels was assessed using a 4-point scale. Quantitative parameters including SNR, contrast-to-noise ratio (CNR), contrast ratio (CR), and coefficient of variation (CV) were evaluated. Aortic diameters were measured, and reproducibility was assessed using Bland-Altman analysis and the intraclass correlation coefficient (ICC). Image acquisition times were also compared.</p><p><strong>Results: </strong>Visual assessment demonstrated significantly higher scores with CS-MRA compared to cMRA across all evaluated thoracic vessels in both volunteers and patients (median score: 3 vs. 2, P < 0.05). Quantitative analysis showed that CS-MRA yielded significantly higher SNR, CNR, and CR (P < 0.05 for all), along with better signal homogeneity (lower CV). CS-MRA showed excellent intra- and inter-observer agreement for aortic diameter measurements, with ICCs ≥ 0.91 in volunteers and ≥ 0.95 in patients. CS-MRA also achieved significantly shorter acquisition times (volunteers: 5.3 ± 1.4 min vs. 6.0 ± 1.7 min, P < 0.01; patients: 5.1 [4.6-6.3] min vs. 6.9 [5.0-9.6] min, P < 0.01).</p><p><strong>Conclusion: </strong>CS-MRA provides superior image quality, comparable measurement reproducibility, and significantly reduced acquisition times compared to cMRA. These findings support the clinical utility of CS-MRA as an efficient and reliable non-contrast technique for thoracic vascular 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":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13500209/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147793495","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":"MR Imaging of Wallenberg Syndrome Using Accelerated 3D-FLAIR with T2 Preparation and Magnetization Transfer Contrast: A Case Report.","authors":"Yusuke Ayabe, Noriko Oyama-Manabe, Nobuyoshi Ohmi, Yoshimasa Ikeda, Yoshimasa Koyama","doi":"10.2463/mrms.ici.2025-0175","DOIUrl":"10.2463/mrms.ici.2025-0175","url":null,"abstract":"<p><p>We report a case of Wallenberg syndrome associated with vertebral artery occlusion and suspected atherosclerotic changes. The patient was evaluated using accelerated 3D fluid-attenuated inversion recovery MRI incorporating T2 preparation and magnetization transfer contrast pulses. This technique enabled a shortened acquisition time while preserving high image contrast, allowing clear visualization of the lateral medullary infarction. This approach provides a non-contrast, high-resolution method for assessing brainstem infarcts and may contribute to improved diagnostic accuracy in the acute setting.</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":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13504077/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147625316","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":"Image Distortion Correction for Diffusion MR Imaging Using a Transformer-based U-Net.","authors":"Tsuyoshi Ueyama, Erika Takahashi, Naoto Fujita, Yuichi Suzuki, Shohei Inui, Koichiro Yasaka, Hideyuki Iwanaga, Osamu Abe, Yasuhiko Terada","doi":"10.2463/mrms.mp.2024-0149","DOIUrl":"10.2463/mrms.mp.2024-0149","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the performance of a Transformer-based U-Net, TransDisCo, for distortion correction in clinical diffusion-weighted imaging (DWI), including high b-value DWI, diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI) and, furthermore, to compare its efficacy with an established U-Net-based method (Synb0) on a clinical dataset including lesion cases.</p><p><strong>Methods: </strong>This study utilized a clinical dataset acquired at the University of Tokyo Hospital, comprising DWI data from patients (including cases with brain tumors and cerebrovascular disorders) suitable for DTI and DKI analysis. We compared the distortion-correction performance of our proposed TransDisCo with that of Synb0, a U-Net-based model. Both methods were trained on T1-weighted images and uncorrected DWI images, with FMRIB Software Library-corrected DWI images used as ground truth. To assess the contribution of the self-attention mechanism in TransDisCo, an ablation study was conducted using a convolutional neural network (CNN)-based variant, in which encoder Transformer blocks were replaced with convolutional blocks. We evaluated corrected DWI images and derived DTI/DKI maps using peak SNR, structural similarity, mutual information, and Dice coefficients.</p><p><strong>Results: </strong>All 3 models corrected distortions in the clinical DWI datasets, including high b-value images and derived DTI/DKI maps. Furthermore, TransDisCo demonstrated significantly superior performance compared to Synb0 across quantitative metrics, particularly in preserving anatomical details and reducing artifacts, even in the presence of pathological changes. Additionally, in the ablation study, TransDisCo outperformed the CNN-based variant trained under identical conditions, indicating that the self-attention mechanism, which enables content-adaptive long-range feature interactions, of the Transformer-based encoder contributed to the observed performance gains.</p><p><strong>Conclusion: </strong>TransDisCo alleviates limitations of existing CNN-based models and represents a promising approach to DWI distortion correction that surpasses conventional U-Net-based methods on clinical data with diverse pathologies. It has the potential to improve the precision and reliability of diffusion MRI across a wide range of imaging conditions and clinical applications.</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":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13500223/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936594","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":"Feasibility of Ultrashort Echo Time MR Imaging for the Detection of Subclinical Achilles Enthesitis in Psoriasis and Psoriatic Arthritis.","authors":"Takeshi Fukuda, Yoshinori Umezawa, Mami Momose, Akihiko Asahina, Akira Ogihara, Ryuichi Itou, Hisashi Kitagawa, Katsutoshi Murata, Stefan Sommer","doi":"10.2463/mrms.bc.2026-0026","DOIUrl":"10.2463/mrms.bc.2026-0026","url":null,"abstract":"<p><p>Subclinical inflammation (SI) is clinically relevant in psoriasis (PsO) and psoriatic arthritis (PsA), but quantitative imaging biomarkers are lacking. We evaluated the feasibility of ultrashort echo time (UTE) bicomponent MRI for quantifying Achilles enthesis SI. Conventional MRI showed no group differences, whereas short T2* (T2*_s) values were significantly elevated in PsO/PsA compared with healthy volunteers. These findings support the feasibility of UTE bicomponent analysis, as a promising tool for evaluating SI and warrant further investigation.</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":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13500371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147984534","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":"Reverse Encoding Distortion Correction of Female Pelvic Diffusion-weighted Imaging on a 1.5-T MR System: Influence on Image Quality and Apparent Diffusion Coefficient Measurements for Both In Vitro and In Vivo Studies.","authors":"Takahiro Ueda, Kaori Yamamoto, Natsuka Yazawa, Yuichiro Sano, Masato Ikedo, Masanori Ozaki, Takahiro Matsuyama, Masahiko Nomura, Yoshiyuki Ozawa, Daisuke Takenaka, Takeshi Yoshikawa, Yoshiharu Ohno","doi":"10.2463/mrms.mp.2025-0202","DOIUrl":"10.2463/mrms.mp.2025-0202","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate whether reverse encoding distortion correction (RDC) improves image quality and maintains apparent diffusion coefficient (ADC) measurements in diffusion-weighted imaging (DWI) on female pelvic MRI using a 1.5-T in in vitro and in vivo studies.</p><p><strong>Methods: </strong>This retrospective, institutional review board-approved study included both in vitro and in vivo analyses of 31 women (mean age, 41 ± 15 years; range, 24-80 years) who underwent pelvic MRI between January and March 2022. T2-weighted image (T2WI) and DWI with and without RDC were acquired, and ADC maps were generated. Quantitative metrics included SNR, contrast-to-noise ratio (CNR), ADC values, and deformation ratio (DR), defined as the proportional area discrepancy between DWI and T2WI for the uterine corpus, cervix, ovary, and lesions. Qualitative assessments-overall image quality (OIQ), deformation severity (DS), and diagnostic confidence level (DCL)-were independently scored by 2 blinded radiologists using 5-point scales.</p><p><strong>Results: </strong>In vitro SNR and ADC values showed no significant differences between DWI with and without RDC, with strong correlations to reference measurements (ρ = 0.99, P < 0.001). In vivo, SNR, CNR, and ADC values of the myometrium, cervix, and ovary did not differ significantly between 2 methods (P > 0.05). DRs were significantly lower in DWI with RDC than in DWI without RDC (P ≤ 0.0003). ADC values showed strong correlations between DWI with and without RDC on uterine corpus, cervix, ovary and lesions (ρ = 0.82-0.90, P < 0.001). Qualitative scores improved with RDC: higher OIQ (P = 0.0004), lower DS (P = 0.0004), and higher DCL (P = 0.03). Interobserver agreement ranged from substantial to almost perfect (κ = 0.78-0.97).</p><p><strong>Conclusion: </strong>RDC improves image quality and reduces image distortion in DWI on female pelvic MRI at a 1.5-T, while maintaining ADC measurements in in vitro and in vivo settings.</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":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13500117/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147793536","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":"Substantially Higher Vestibular Hydrops Agreement in Older Patients Assessed by Non-contrast vs. Contrast-enhanced MRI: A Preliminary Study.","authors":"Shinji Naganawa, Rintaro Ito, Yutaka Kato, Masumi Kobayashi, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone","doi":"10.2463/mrms.mp.2025-0199","DOIUrl":"10.2463/mrms.mp.2025-0199","url":null,"abstract":"<p><strong>Purpose: </strong>This preliminary study aimed to investigate the agreement in endolymphatic hydrops (EH) grading between high-resolution non-contrast and contrast-enhanced HYDROPS (HYbriD of Reversed image Of Positive endolymph signal and native image of positive perilymph Signal) techniques in the same subjects and to clarify the effect of patient age on the concordance between the 2 methods.</p><p><strong>Methods: </strong>A retrospective study was performed on 12 patients (24 ears; age range: 24-76 years) suspected of EH, all of whom underwent both non-contrast and 4-hour post-contrast 3T MRI. EH in the cochlea and vestibule was graded by the Nakashima scale. Agreement analyses were assessed using the weighted Cohen's kappa (κ). Statistical significance, including the difference between Younger (24-54 years) and Older (57-76 years) patient subgroups, was determined via bootstrap analysis.</p><p><strong>Results: </strong>The overall agreement between non-contrast and contrast-enhanced methods was fair for both the cochlea (κ = 0.343) and vestibule (κ = 0.398). Subgroup analysis revealed a significant age-related difference in vestibular agreement (P = 0.005), showing substantial agreement in the Older group (κ = 0.795) but only slight agreement in the Younger group (κ = 0.113). No significant age-related difference was found for cochlear agreement. Quantitatively, the non-contrast method demonstrated a significantly lower contrast-to-noise ratio compared to the contrast-enhanced method.</p><p><strong>Conclusion: </strong>The concordance between non-contrast and contrast-enhanced MRI for EH assessment is site- and age-dependent. The substantially higher agreement found in older patients suggests that age-related physiological changes facilitate non-contrast visualization. However, caution is advised when interpreting non-contrast findings in younger patients due to potential risks of vestibular overestimation and cochlear underestimation. Given the preliminary nature and small sample size of this study, further investigations with larger cohorts are necessary to validate these findings and the appropriateness of age-based categorization.</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":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481293/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146168384","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":"Preparation and MR Imaging Study of a Recombinant Surface Antibody Superparamagnetic Iron Oxide Nanoparticle-EPC1 Molecular Probe for Hepatic Alveolar Echinococcosis.","authors":"Weili Tian, Wenchao Ji, Wenya Liu, Peng Chen, Jun Li, Xueqi Sheng, Yaomiao Dong","doi":"10.2463/mrms.mp.2025-0096","DOIUrl":"10.2463/mrms.mp.2025-0096","url":null,"abstract":"<p><strong>Purpose: </strong>To establish a new hepatic alveolar echinococcosis (HAE) model, construct an EPC1 antibody-conjugated superparamagnetic iron oxide nanoparticle (SPION) molecular probe and evaluate the probe's efficacy in the targeted MRI of HAE.</p><p><strong>Methods: </strong>Thirty C57 female mice (9-10 weeks; 17-22g) were used to establish an HAE model via hepatic portal vein infection. Twenty successfully HAE-modeled mice were randomly divided into a control group, which was given a simple SPION tracer, and an experimental group, which was given a complex SPION-EPC1 tracer. In addition, a blocking group (n = 5), in which mice received an excess dose of free EPC1 antibody prior to injection of the SPION-EPC1 tracer, was included to assess EPC1-dependent targeting, and a gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) group (n = 5), which received 0.1 mmol/kg of Gd-DTPA, was included to provide a reference clinical contrast agent. MRI was performed using an animal MRI scanner, and T1- and T2-weighted imaging sequences were utilized to assess lesion characteristics before and after tracer injection at 1 and 4h time points. Subsequently, T2 signal intensity, the lesion SNR, and the lesion-to-liver contrast-to-noise ratio were measured by 2 blinded physicians (>5 years experience) using ImageJ software. Comparisons were made between plain and post-injection scans at 1 and 4h. Independent sample t-tests and non-parametric tests were applied to compare signal intensities and SNR values.</p><p><strong>Results: </strong>The SPION-EPC1 probe significantly decreased T2 signal intensity and lesion SNR in the experimental group at both 1 (T2 intensity: -24.3%; SNR: -35.2%) and 4h (T2 intensity: -23.5%; SNR: -43.1%) compared with plain scans. By contrast, the control group showed only transient decreases, with no significant differences at 4h. In the EPC1-blocking group, the T2-signal decrease at 4h was markedly attenuated compared with that of the SPION-EPC1 group and comparable to that of the SPION group, supporting EPC1-dependent targeting.</p><p><strong>Conclusion: </strong>The SPION-EPC1 molecular probe demonstrated improved sensitivity and long-lasting effects in the MRI detection of HAE lesions, offering a promising tool for early diagnosis and the potential advancement of clinical practice in HAE imaging.</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":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13481155/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146168434","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}