NMR in Biomedicine最新文献

{"title":"Longitudinal Metabolic Alterations of the Visual Cortex in Diabetic Retinopathy Rats Using High-Field Proton Magnetic Resonance Spectroscopy.","authors":"DanDan Shen, Yuzhe Wang, Yin Wang, Rong Wang, Min Wang, Jiawei Kuang, Yue Geng, Yang Zhan, Yuwen Zhang, He Wang, Xinghuai Sun, Zuohua Tang","doi":"10.1002/nbm.70253","DOIUrl":"10.1002/nbm.70253","url":null,"abstract":"<p><p>The visual impairment in diabetic retinopathy (DR) has been associated with the pathophysiological changes of the entire visual pathway. However, only a few studies have specifically examined dynamic metabolic changes in the visual cortex of DR. The purpose of the study was to longitudinally characterize dynamic metabolic alterations in the visual cortex of DR rats using 11.7 T proton magnetic resonance spectroscopy (¹H-MRS), with histopathological validation. 3-month-old male DR rats and matched healthy rats were randomly selected into the study (n = 7/group), with metabolic assessments in the visual cortex conducted at 2, 4, 6, and 8 weeks. Immunohistochemical analyses were performed at 8 weeks to evaluate visual cortex alterations. The metabolite concentration ratios were compared between DR rats and controls at different time points using repeated measures analysis of variance followed by Bonferroni post hoc tests. The comparison of immunohistochemical indicators between DR rats and controls was evaluated using independent samples t test. p < 0.05 was considered statistically significant. Compared to controls, DR rats exhibited significantly higher Ins/tCr and Cho/tCr ratios in the visual cortex at 2, 4, 6, and 8 weeks, while NAA/tCr, Glu/tCr, GABA/tCr, and Tau/tCr ratios were significantly lower, respectively (all p < 0.05). Notably, Ins/tCr and Cho/tCr progressively increased with the progression of DR, whereas NAA/tCr, Glu/tCr, GABA/tCr, and Tau/tCr gradually decreased correspondingly (all p < 0.05). At 8 weeks, DR rats showed a reduction in NeuN-, Tau-, NR2B-, and GABA_A-positive cells, along with an increased expression of GFAP-positive cells, compared to controls (all p < 0.0001). In conclusion, with the progression of DR, the dynamic metabolic alterations in the visual cortex indicated ongoing cortical degeneration, impaired neurotransmitter metabolism, dysregulated cellular homeostasis and glial cell proliferation, highlighting the underlying neurobiological mechanisms of visual impairment in DR.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70253"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147276896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patient-Specific Biases in Fat Fraction Estimates of Malignant Bone Marrow due to Relaxation Times Measured With STEAM at 3T.","authors":"Yassine N Azma, David J Collins, Pete J Lally, Nina Tunariu, Dow-Mu Koh, Christina Messiou, Geoff Charles-Edwards, Christina Triantafyllou, Neal K Bangerter, Jessica M Winfield","doi":"10.1002/nbm.70242","DOIUrl":"10.1002/nbm.70242","url":null,"abstract":"<p><p>Semiquantitative fat fraction estimation using 2-point Dixon sequences is widely used in whole-body (WB) MR imaging for malignant bone disease but is biased by relaxation times. Understanding this bias requires water- and fat-specific relaxometry data in normal-appearing marrow and lesions. This study measured bone marrow relaxation times in healthy volunteers and WB-MRI patients using MRS at 3T. Five healthy female volunteers (mean age 38.0 ± 2.5 years) and 24 patients with malignant bone disease undergoing clinical WB-MRI (13 male; mean age 67.7 ± 9.7 years; primary cancers: breast = 5, melanoma = 1, multiple myeloma = 8, prostate = 10) underwent variable inversion/echo time STEAM and 3D gradient echo fat-water imaging. MRS water and fat peaks were fitted to determine T1, T2, R2* (from linewidths) and proton density fat fraction (PDFF). Scan-rescan repeatability of MRS parameters was assessed in volunteers. Lesions were classified by disease state according to clinical reports and segmented in Dixon imaging data for comparison of fat fraction estimates with MRS. Repeatability was evaluated using coefficients of variation. Summary statistics (mean, standard deviation and range) were reported; exploratory inferential statistics were also determined with normality (Shapiro-Wilk) and variance (Levene's) tests before one-way ANOVA and Tukey's comparisons (p < 0.05). Monte-Carlo simulations assessed relaxation bias on PDFF. All quantitative MRS parameters were repeatable (coefficient of variation < 10%). Water T1 and T2 were most sensitive to disease state in patients, ranging from 1121 to 2206 and from 15 to 71 ms respectively, and were demonstrated to substantially affect 2-point Dixon fat fraction estimates with Monte-Carlo simulation. Imaging PDFF achieves closer agreement with MRS PDFF than 2-point Dixon methods. These findings remain preliminary due to the small sample size, but they suggest value in future studies with larger cohorts evaluating water relaxation times or PDFF in malignant bone disease.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70242"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12932037/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147284603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unravelling Structural and Metabolic Alterations in the Hippocampus and Anterior Cingulate Cortex Using Integrated MRI and MRS in Major Depressive Disorder.","authors":"Vishwa Rawat, Deepti Upadhyay, Gagan Hans, Shivam Pandey, Pratap Sharan, Uma Sharma","doi":"10.1002/nbm.70261","DOIUrl":"10.1002/nbm.70261","url":null,"abstract":"<p><p>The present study investigated structural and metabolic changes in the two brain regions of the limbic system, right hippocampus and anterior cingulate cortex (ACC), implicated in the pathophysiology of major depressive disorder (MDD). Three-dimensional-T1-weighted magnetic resonance imaging (MRI) and single-voxel in vivo magnetic resonance spectroscopy (MRS) were performed on a 3.0 T MRI in patients with MDD (n = 64) and healthy controls (HC, n = 47). The severity of depression was assessed using clinical scales (Hamilton Depression Rating Score [HDRS] and Montgomery-Åsberg Depression Rating Score [MDRS]). The automated volumetric segmentation of the T1-weighted MR images was performed using Freesurfer 7.2.0. The tissue-corrected concentration of neurochemicals was quantified using Osprey software. The relationship between hippocampal and ACC metabolite levels was examined with their volumes. Additionally, the levels of neurochemicals and volumes were correlated with the severity of depression. After adjusting for multiple comparisons using the false discovery rate (FDR), the concentration of total NAA (t-NAA, N-acetyl aspartate+ N-acetyl-aspartyl-glutamate [NAAG]), myoinositol (mI), total choline (tCho) and total creatine (tCr) were significantly reduced (p_FDR < 0.05) in the hippocampus of the MDD patients. The ACC in MDD patients showed significantly higher levels of tNAA and tCr (p_FDR < 0.05). Further, the volume of ACC was significantly increased in patients with MDD. Although hippocampal volume was not different between the two groups, a weak positive correlation was observed between the tCho levels and the volumes of the hippocampus and mid-ACC. Hippocampal glutamate + glutamine (Glx) levels showed a weak negative correlation with the MDRS score, whereas ACC tCho showed a negative correlation with the HDRS score. Our observations suggested that the pathophysiology of MDD is not only associated with hippocampal neurodegeneration but may also involve glial proliferation, leading to increased ACC volume. These changes might alter neurotransmission in the limbic system, contributing to the pathophysiology of depression.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70261"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147444407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D Radial Knee Imaging at 0.55 T: Simultaneous T₁-T₂ Mapping and Synthetic Contrast Generation in Under 4 min.","authors":"Nicolás Garrido, Diego Pedraza, Carlos Castillo-Passi, Dabne Barrera, Claudia Prieto, René Botnar","doi":"10.1002/nbm.70265","DOIUrl":"10.1002/nbm.70265","url":null,"abstract":"<p><p>Quantitative MRI (T₁-T₂) has been shown to be useful for early diagnosis of osteoarthritis (OA) in the knee at 1.5 and 3 T. However, limited research has been performed at 0.55 T. In this study, we aim to develop and evaluate the feasibility of a 3D joint T₁-T₂ mapping estimation and synthetic contrasts radial sequence for quantitative and anatomical water-fat imaging of the knee at 0.55 T. The proposed sequence consists of a free-running, 3D-golden angle radial trajectory preceded with inversion recovery and <math> <semantics> <mrow><msub><mi>T</mi> <mn>2</mn></msub> </mrow> <annotation>$$ {T}_2 $$</annotation></semantics> </math> -preparation pulses. Reconstruction of images is performed with parallel imaging and high-dimensional low-rank patch-based regularization. A water-fat separation technique is employed to obtain water and fat images, and T₁-T₂ maps can be obtained for water and the echo images via Bloch-equation dictionary matching. The sequence was validated on a standardized phantom and in 16 healthy subjects. Phantom results are in good agreement with SE references, with biases of <math> <semantics><mrow><mn>1.78</mn></mrow> <annotation>$$ 1.78 $$</annotation></semantics> </math>  ms for <math> <semantics> <mrow><msub><mi>T</mi> <mn>1</mn></msub> </mrow> <annotation>$$ {T}_1 $$</annotation></semantics> </math> and <math> <semantics><mrow><mo>-</mo> <mn>0.23</mn></mrow> <annotation>$$ -0.23 $$</annotation></semantics> </math> ms for <math> <semantics> <mrow><msub><mi>T</mi> <mn>2</mn></msub> </mrow> <annotation>$$ {T}_2 $$</annotation></semantics> </math> . In vivo, the average mean in the articular cartilage was <math> <semantics> <mrow><msub><mi>T</mi> <mn>1</mn></msub> <mo>=</mo> <mn>460</mn> <mo>±</mo> <mn>45</mn></mrow> <annotation>$$ {T}_1=460pm 45 $$</annotation></semantics> </math> ms and <math> <semantics> <mrow><msub><mi>T</mi> <mn>2</mn></msub> <mo>=</mo> <mn>33</mn> <mo>±</mo> <mn>4</mn></mrow> <annotation>$$ {T}_2=33pm 4 $$</annotation></semantics> </math> ms, compared to <math> <semantics> <mrow><msub><mi>T</mi> <mn>1</mn></msub> <mo>=</mo> <mn>394</mn> <mo>±</mo> <mn>57</mn></mrow> <annotation>$$ {T}_1=394pm 57 $$</annotation></semantics> </math> ms, <math> <semantics> <mrow><msub><mi>T</mi> <mn>2</mn></msub> <mo>=</mo> <mn>44</mn> <mo>±</mo> <mn>10</mn></mrow> <annotation>$$ {T}_2=44pm 10 $$</annotation></semantics> </math> ms for the reference sequences. Synthetic contrast images produced with the sequence are comparable to the references in terms of contrast to noise ratio (CNR) and relative contrast metrics. The feasibility of 3D joint T₁-T₂ mapping of the knee at 0.55 T in a single scan of ~3 min was demonstrated, showing promising results for efficient knee imaging. Studies in a larger cohort of patients with osteoarthritis at 0.55 T are now warranted.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70265"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147474558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimodal MRI Reveals Cerebral and Vascular Amyloid-Driven Myeloarchitectural Disorganization in a Mouse Model of Alzheimer's Disease.","authors":"Syed Salman Shahid, Xuan Li, Mario Dzemidzic, Erin E Jarvis, Yomna Takieldeen, Aibo Wang, Donna Wilcock, Yu-Chien Wu","doi":"10.1002/nbm.70262","DOIUrl":"10.1002/nbm.70262","url":null,"abstract":"<p><p>Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder involving a complex interaction of cerebral and vascular amyloid-beta (Aβ) accumulation, myelin disruption, lipid alterations, and cerebrovascular dysfunction. The early detection and differentiation of these interconnected pathologies remain challenging. To understand the effect of cerebral and vascular Aβ on regional myeloarchitecture and lipid composition, we developed a novel multimodal neuroimaging approach integrating quantitative MRI (qMRI), chemical exchange saturation transfer (CEST) MRI, and immunohistochemistry (IHC). The framework was applied to a 10-month-old mouse model exhibiting both cerebral and vascular amyloid pathologies. High-resolution in vivo MRI was performed using a 9.4 Tesla scanner. The results suggest region-specific vulnerability to Aβ pathology with significant regional increases in apparent transverse relaxation rate (R2*, p < 0.05; Hedges' g = 1.22) and quantitative susceptibility mapping (χ, p < 0.01; Hedges' g = 1.99) within the hippocampus of ARTE10 mice compared to wild-type littermates. Multislice CEST-based Z-spectra were used with multipool Lorentzian fitting and quantitative T1 longitudinal relaxation maps to obtain nuclear Overhauser enhancement (NOE) weighted apparent exchange-dependent relaxation (AREX) maps. NOE _{(-3.5 ppm)}-sensitive CEST imaging contrast showed region-specific changes in the hippocampus (p < 0.01; Hedges' g = -1.81), corpus callosum (p < 0.01; Hedges' g = -2.39), and thalamus (p < 0.01; Hedges' g = -2.64) of ARTE10 animals relative to WT littermates. Hippocampal Aβ burden, iron load, and myelin density were quantified using immunohistochemistry, suggesting strong Aβ plaque presence and elevated iron load in the hippocampi of ARTE10 mice compared to WT mice. Collectively, our results demonstrate the utility of this multimodal MRI framework in identifying sensitive and specific biomarkers of amyloid-driven myeloarchitectural and molecular changes. The proposed framework offers a valuable tool for enhancing early detection, understanding different pathophysiological pathways, and facilitating therapeutic monitoring and targeted intervention strategies.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70262"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12983127/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147444375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"³¹P-MRS of the Human Heart at 7 T With an Integrated Whole-Body ³¹P Radiofrequency Transmit Coil.","authors":"Mark W J M Gosselink, Martijn Froeling, Kathy Verkerk, Dennis W J Klomp, Adrianus J Bakermans, Jeanine J Prompers","doi":"10.1002/nbm.70248","DOIUrl":"10.1002/nbm.70248","url":null,"abstract":"<p><p>Phosphorus-31 magnetic resonance spectroscopy (³¹P-MRS) can be used to characterize the steady-state in vivo myocardial energy status via the phosphocreatine (PCr) over adenosine triphosphate (ATP) tissue concentration ratio. Although used in many studies, this modality suffers from low sensitivity and poor measurement precision. This work reports on the acquisition of ³¹P-MR spectra of the in vivo human heart using a 7 T MR system equipped with an integrated whole-body RF transmit coil for ³¹P spin excitation. Eight volunteers (male/female, n = 4/4) underwent ³¹P-MRS at 7 T twice, using a low-flip angle, short-repetition time 3D ³¹P-MR spectroscopic imaging sequence with a 20-mm isotropic resolution and a 21-min acquisition time. A 16-channel ³¹P receive array was used for signal reception. Myocardial voxels were identified on transversal cine proton MR images. Signals of PCr, phosphodiesters (PDE), and inorganic phosphate (P_i) were quantified relative to ATP and corrected for partial saturation and blood signal contamination. Bland-Altman analyses were used to establish intersession measurement repeatability. A comparison of supine and prone positioning was made for two subjects, yielding similar results but superior comfort for lying supine. Mid-septal myocardial PCr/ATP was 1.85 ± 0.37, with a repeatability coefficient of 17.7%. The repeatability coefficients for P_i/ATP and PDE/ATP were 142.7% and 51.6%, respectively. Using the spatially homogeneous ³¹P spin excitation with the integrated whole-body RF transmit coil, we made quantitative estimates of the myocardial energy status at a higher precision than previously achieved at lower main magnetic field strengths. The noninvasive nature and high precision of the presented ³¹P-MR spectroscopic imaging approach will allow for therapeutic efficacy monitoring with repeated measurements in longitudinal study designs and investigations of normal physiology in healthy volunteers.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70248"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12921427/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146227447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dipolar Order Relaxation Measurements of Lipid Membranes: Challenges of Jeener-Broekaert Experiments.","authors":"Niklas Wallstein, Axelle Grélard, Olivier M Girard, Antoine Loquet, André Pampel, Guillaume Duhamel","doi":"10.1002/nbm.70237","DOIUrl":"10.1002/nbm.70237","url":null,"abstract":"<p><p>An ongoing goal of research is to achieve a better understanding of the contrast mechanisms associated with myelin, including inhomogeneous magnetization transfer (ihMT). IhMT requires residual dipolar couplings between motion-restricted restricted ('semisolid') protons and a sufficiently long dipolar order relaxation time (T_1D). Although the measured ihMT ratio depends strongly on T_1D, direct observation and quantification of the differences in T_1D of biological tissues via MRI are still not feasible. Instead, complex modelling of a limited amount of experimental data is required, which is based on compartment models of at least two proton reservoirs, indicating the need for external referencing. The Jeener-Broekaert (JB) measurement is the 'gold standard' method for T_1D quantification, originally developed for the application to 'pure solids'. Recently, the JB method has been used to study lipid model systems and tissues. However, the translation from 'pure solids' to heterogeneous systems characterized by protons with different mobilities proved more challenging than initially anticipated. In particular, strong unwanted signal contributions related to 'Zeeman' order, surviving established phase-cycling schemes, biased the observed signal decay. Here, by modifying the JB sequence by adding a 180° refocusing pulse between the first two RF pulses significantly improved the overall performance, as demonstrated by experiments and additional simulations. Consequently, the reliability of T_1D quantification extracted from JB measurements in the investigated lipid model system could be considerably enhanced, enabling future applications to biological tissue. A detailed discussion of additional effects influencing the observed JB signal decay, including unavoidable signal contributions from other zero-quantum coherences or exchange processes, is provided. Therefore, the quantitative T_1D estimates resulting from JB experiments in heterogeneous tissue should not inevitably be considered as 'gold standard' for referencing of T_1D estimates of quantitative ihMT analysis. Rather, under these conditions, it is more appropriate to refer to them as 'apparent T_1D' values.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70237"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147276876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hypoxia Imaging in Hepatic Fibrosis: A Preliminary Application of CAIX-Targeted MRI Probe in Rats.","authors":"Xiaomin Duan, Longyang Xiao, Haichen Zhao, Yuanxiang Gao, Lili Wang, Haiyang Yu, Xiaoyuan Zhou, Xiaojuan Shi, Zhiming Li","doi":"10.1002/nbm.70249","DOIUrl":"10.1002/nbm.70249","url":null,"abstract":"<p><p>This study aimed to validate the feasibility of hypoxia-targeted magnetic resonance imaging (MRI) molecular probe (CAIX-Gd) for evaluating hypoxia status in rats with hepatic fibrosis. A macrocyclic ligand compound (Compound 3) was synthesized using the carbonic anhydrase IX (CAIX) inhibitor acetazolamide as the targeting moiety, and its structure was confirmed by ¹H-NMR spectroscopy. CAIX-Gd was then prepared by chelating gadolinium, with free gadolinium content quantified via the xylenol orange assay. In biocompatibility tests, CAIX-Gd administration showed no significant histopathological changes compared with saline controls. For hypoxia detection, rats were divided into three groups: (A) hepatic fibrosis (HF) with CAIX-Gd, (B) HF with DTPA-Gd, and (C) normal controls (NC) with CAIX-Gd. The difference in T1 relaxation time (∆T1) pre- and post-contrast was measured in regions of interest (ROI). HF rats showed increased collagen deposition (Masson staining), α-SMA activation, and elevated hypoxia markers (PIMO/HIF-1α) compared to controls (all p < 0.05). In group C, mild ∆T1 shortening was seen at 10 min post-injection. While ∆T1 continuously decreased in group B, the shortening was significantly greater in group A (p < 0.05), peaking at 10 min. In conclusion, the CAIX-Gd probe was successfully synthesized and demonstrated potential for the non-invasive MRI detection of hypoxia in hepatic fibrosis.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70249"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147276934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective Cell Size MRI for the Diagnosis and Grading of Clinically Significant Prostate Cancer: A Feasibility Study.","authors":"Hao Cheng, Jie Lu, Ming Liu, Wei Zhang, Jinxia Zhu, Min Chen, Dan Wu, Chunmei Li","doi":"10.1002/nbm.70267","DOIUrl":"10.1002/nbm.70267","url":null,"abstract":"<p><p>Clinically significant prostate cancer (csPCa) and benign prostate tissue are composed of distinct cell populations. Selective size imaging using filters via diffusion times (SSIFT) MRI, a novel technique generating cell size-weighted maps sensitive to specific cell sizes (e.g., cancer cells), has an unclear clinical value in prostate cancer. This study aimed to evaluate whether SSIFT MRI can serve as a novel imaging biomarker for prostate cancer, specifically for discriminating csPCa from clinically insignificant disease (CIS). A total of 152 men (89 with csPCa and 63 with CIS) suspected of csPCa were prospectively enrolled, with 229 lesions (93 with csPCa and 136 with CIS) delineated. SSIFT MRI data were acquired using pulsed and oscillating gradient diffusion sequences to generate incremental AUC (iAUC). We evaluated the performance of iAUC, the apparent diffusion coefficient (ADC), and prostate-specific antigen density (PSAD) in discriminating csPCa from CIS and assessing Gleason grade group (GGG). Additionally, correlations between iAUC and pathologic parameters (nuclei fraction, diameter, and cellularity) were analyzed in patients with whole histopathologic slides. Higher GGG was associated with increased iAUC values (GGGs 1-5: 3.34% ± 1.28%, 5.31% ± 2.33%, 6.18% ± 2.71%, 6.36% ± 2.23%, and 6.23% ± 1.15%, respectively). For distinguishing csPCa from CIS, iAUC exhibited the highest diagnostic performance, with AUCs of 0.91 (peripheral zone), 0.86 (transitional zone), and 0.89 (whole prostate). In per-patient analysis, the combined model incorporating iAUC, ADC_50ms, and PSAD achieved the highest diagnostic accuracy (86%, 131/152) and AUC (0.93; 95% CI: 0.88-0.97). Histopathological analysis revealed a mean prostate cancer nuclei diameter of 10.98 ± 1.81 μm, within the SSIFT filter range (10-20 μm). These findings suggest that SSIFT MRI shows promise as a novel imaging biomarker for prostate cancer, enabling noninvasive identification of csPCa and optimizing clinical decision-making.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70267"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147444413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Multi-Component Echo Decay in Achilles Tendon by NMR Spectroscopy.","authors":"Theodore Aptekarev, Gregory Furman, Vladimir Sokolovsky, Yang Xia","doi":"10.1002/nbm.70247","DOIUrl":"10.1002/nbm.70247","url":null,"abstract":"<p><p>Fibrous tissues are characterized by angular anisotropy of relaxation times at the nuclear magnetic resonance (NMR) testing. The anisotropy is associated with the water distribution inside such tissues, and its determination requires multiple experiments with the sample rotation relative to the magnetic field. In this paper a quantitative link between a single NMR echo decay and the structure and fluctuations of the water-filled nanocavity in tendon is established, without orientation-dependent relaxation measurements. Echo decays were acquired from Achilles tendon using the Carr-Purcell-Meiboom-Gill and spin-locking sequences. To determine the relationship between the NMR relaxation and the structure and fluctuations of water-filled nanocavities, a physical model was used based on the representation of the tendon as a set of nanocavities and the averaged Hamiltonian of the dipole-dipole spin interaction. Two distinct nanocavity types were identified, which differ in the parameters of the nanocavity structure and their fluctuations. Non-invasive quantitative assessment of the nanocavity structural characteristics opens a way to develop biomarkers for detecting pathological changes in a tendon.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"39 4","pages":"e70247"},"PeriodicalIF":2.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12965050/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147365787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}