NMR IN BIOMEDICINE生物医学核磁共振
NMR IN BIOMEDICINE(英文缩写 NMR BIOMED),ISSN 0952-3480,eISSN 1099-1492,中文译名:生物医学核磁共振 是一本学术期刊。本页汇总该期刊的最新影响因子、分区信息以及最新收录于 PubMed 的文献,帮助您快速了解期刊全貌。
发文量统计区间：2025-10-01 至 2026-09-30，按本站收录文献的发表日期统计。
期刊介绍
历年影响因子趋势
| JCR 数据年份 | 影响因子 | JCR 分区 |
|---|---|---|
| 2021 | 4.478 | Q1 |
| 2022 | 2.900 | Q2 |
| 2023 | 2.700 | Q1 |
| 2024 | 2.700 | Q1 |
| 2025 | 2.800 | Q2 |
NMR IN BIOMEDICINE 最新收录文献
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1. Validation of a Novel, Low-Cost, Portable MRI-Compatible Exercise Device in Healthy Volunteers and Patients With Pulmonary Hypertension.
PMID:日期:2026-10-05The value of exercise cardiovascular magnetic resonance (CMR) has been shown in many clinical scenarios. We have developed a novel MR-compatible exercise device and aim to validate it against the reference standard MR-conventional ergometer. The novel device consisted of two half-pipes fixed to a wooden base, with participants wearing knee-length socks with a 0.5 kg weight in each sock. Increased workload was achieved by increasing the rate of alternating leg flexion and extension in time with a bleep sound of increasing frequency. Twenty subjects (10 healthy volunteers, 10 patients with pulmonary arterial hypertension) performed two CMR-augmented cardiopulmonary exercise tests (CMR/CPET) using the novel exercise device and a conventional ergometer in a randomised order. Comparing peak metrics elicited on both exercise devices, there was a moderate correlation in peak oxygen consumption (VO, r = 0.86, p < 0.001), cardiac output (CO, r = 0.73, p < 0.001), stroke volume (SV, r = 0.90, p < 0.001), peak heart rate (HR, r = 0.65, p = 0.002) and peak arteriovenous oxygen content gradient (ΔavO, r = 0.71, p < 0.001). However, all metrics were significantly lower with the novel device. Both devices were able to elicit statistically significant differences in VO, HR and right ventricular ejection fraction (RVEF) between patients and healthy subjects (p ≤ 0.04). We have created a simple, easy to use and affordable exercise device for the CMR environment. This may encourage greater dissemination of exercise CMR in clinical and research practice.
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2. Fat-Water Swap Artifact Correction in MRI-Based Fat Quantification Using Physics-Informed Deep Learning With Branch Constrained Optimization.
2. 基于物理信息深度学习与分支约束优化的MRI脂肪定量中脂水交换伪影校正PMID:日期:2026-09-29Commonly occurring fat-water swap artifacts in multi-echo MRI hinder accurate estimation of the clinical biomarker, proton density fat fraction (PDFF). This study evaluates a novel physics-informed deep learning (PI-DL) model to correct these swap artifacts. The proposed PI-DL model, the "Swap-Net," utilizes a branch-constrained optimization method to explore different bifurcate regions in the residual function optimized, thereby increasing the probability of reaching global minima, as the swap artifacts are caused by the optimization routine settling into a local minimum. Performance evaluation was conducted using multi-echo MRI of 37 (n = 37) subjects, and this included a cohort of 23 (n = 23) high-resolution MRIs. The proprietary mDixon Quant sequence, with optimized parameter settings for accurate liver fat quantification, served as the clinical standard for benchmarking performance. The results of the quantitative evaluations revealed that the average liver PDFF% from the proposed Swap-Net demonstrated excellent agreement with the clinical standard mDixon Quant (correlation coefficient R of 0.98 in the high-resolution cohort). The qualitative evaluations also showed that the fat-water maps from the Swap-Net contained no swap artifacts. In contrast, other state-of-the-art methods exhibited swap artifacts, particularly in high-resolution MRI. The proposed Swap-Net corrected swap artifacts in MRI-based fat quantification, particularly in high-resolution MRI, enabling high-resolution fat-water imaging.
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3. Investigating Postmortem Blood Clots as Endogenous Contrast for Mesoscopic Cerebrovascular Mapping at 7 T.
PMID:日期:2026-09-29Vascular mapping of fixed postmortem human brain tissue remains biologically complex and technically challenging because postmortem changes, including clot contraction and fragmentation, vascular collapse, and fixation-induced alterations, substantially affect vascular MRI contrast. Furthermore, the mechanisms governing vascular contrast in postmortem MRI remain incompletely understood. In this study, we aim to determine the feasibility and reliability of using blood clot formation as a susceptibility contrast source to improve vascular visibility and enable quantitative assessment on ex vivo MRI. Postmortem brain hemispheres and tissue blocks were imaged to assess vascular conspicuity in the cortex, hippocampus, and white matter. Coagulated blood signal was clearly observed within the postmortem brain surface vasculature, with intact clots in small vessels and partial or discontinuous clotting in larger vessels. High-resolution gradient echo (GRE) imaging of tissue blocks enabled detailed reconstruction of local vascular networks, including intrahippocampal vasculature, for vessel density quantification. Quantitative analysis demonstrated markedly shorter T2* values for blood clots (6.6 ± 2.0 ms) compared with gray matter (34.8 ± 8.9 ms) and white matter (19.1 ± 3.6 ms) at 7 T, resulting in appropriate vascular contrast and conspicuity. Histological hematoxylin-eosin and Luxol Fast Blue staining confirmed intravascular clot formation and localization. These findings demonstrate that blood clots can act as an intrinsic contrast for mesoscopic vascular MRI in the postmortem human brain, enabling detailed assessment of microvascular changes and their pathological correlates relevant to vascular contributions to cognitive impairment and dementia.
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4. Predicting Clinical Improvement in Chronic Low Back Pain Using Exercise-Induced IVIM Perfusion: Threshold Evaluation and Disability-Dependent Effects.
PMID:日期:2026-09-28Chronic low back pain (LBP) is the leading cause of disability worldwide, yet responses to exercise-based rehabilitation vary substantially and remain not well characterized. Impaired activation of the lumbar paraspinal muscles has been proposed as a mechanism limiting rehabilitation treatment response. Intravoxel incoherent motion (IVIM) magnetic resonance imaging assesses muscle diffusion and perfusion after exercise, offering physiological markers of dynamic function. In a previous pilot study, we reported that acute exercise-induced IVIM responses were reduced in individuals with LBP and that thresholds in diffusion (D) and pseudodiffusion (D*) parameters could predict those who would or would not respond to an exercise-based rehabilitation program. The present study aimed to prospectively validate these findings in a larger, independent cohort. Thirty-seven individuals with chronic LBP underwent IVIM before and after an acute standardized lumbar extension exercise, followed by a 12-week rehabilitation program. Participants were classified as responders or nonresponders based on changes in disability after 12 weeks (Δ Oswestry Disability Index Score ≥ or < 0). In line with the pilot study, responders exhibited higher increase in D following acute exercise than nonresponders (p = 0.05). Previously identified thresholds for D and D* did not discriminate between responders and nonresponders within this new cohort (Sn < 0.40 and Sp = 0.65). Exploratory analyses revealed that baseline disability moderated IVIM responses, as a marked increase in D was primarily observed in responders with low baseline disability, whereas individuals with higher disability showed attenuated responses. New significant thresholds were explored within the validation cohort while controlling for disability levels. An increase ≥ 0.014 × 10 mm/s for D predicted who would respond to the exercise-based program, with a Sn of 0.59 and a Sp of 0.90 (area under the curve [AUC] 0.72, 95%CI 0.55 to 0.90, p = 0.02). These findings confirm that acute IVIM responses are associated with rehabilitation outcomes but may be better understood as part of a broader, integrative framework characterizing the physiological mechanisms associated with treatment response. Integrating physiological and clinical factors to better understand variability in treatment response will help guide more personalized approaches to LBP rehabilitation.
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5. Adaptively Optimized Combination of Phased-Array MR Spectroscopy Data Without Noise Correlation Estimation: A Joint Diagonalization Method.
PMID:日期:2026-09-28The adaptively optimized combination (AOC) method optimally combines multichannel magnetic resonance spectroscopy (MRS) data by incorporating noise correlations among receive coil elements/channels. These correlations are typically estimated from noise samples extracted from the fully decayed tails of acquired free induction decays (FIDs). To eliminate the need for FID noise tails and the corresponding interchannel noise correlation estimation, we propose a novel coil-combination method, termed AOC-JD, that exploits the intrinsic multichannel noise information contained in the differences between individual repetitions and the repetition-averaged spectroscopic data. The proposed method is based on joint diagonalization (JD) of two correlation matrices constructed from the individual repetitions and the repetition-averaged multichannel MRS data, thereby circumventing the conventional interchannel noise correlation estimation procedure. The performance of AOC-JD was evaluated using both computer simulations and in vivo human brain experiments. The results demonstrate that, when multichannel FIDs do not contain valid or sufficiently long noise tails, AOC-JD significantly improves the signal-to-noise ratio (SNR) of the combined spectra compared with the conventional singular value decomposition (SVD) method. Moreover, its performance is comparable to that of the original AOC method, which is optimized to maximize the SNR of the combined spectrum, when applicable. These findings demonstrate that AOC-JD provides a theoretically grounded and reliable approach for combining multichannel MRS data when FID noise tails are unavailable or insufficient.
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6. Quantifying Pancreatic Fat Using a Free-Breathing Acquisition in Adults With Obesity Undergoing Diet-Induced Weight Loss-Results From the LION Study.
6. 使用自由呼吸采集对接受饮食诱导减重的肥胖成人进行胰腺脂肪定量——LION研究结果PMID:日期:2026-09-25A free-breathing six-echo radial stack-of-stars acquisition is evaluated as an alternative to Cartesian breath-hold scans for pancreatic fat quantification at 3T. Pancreatic fat deposition was assessed in 18 participants with obesity enrolled in a randomized controlled lifestyle intervention study (LION) using both a Cartesian breath-hold scan and a free-breathing high-resolution stack-of-stars sequence (scan times: 16 s vs. 2 min 55 s). Pancreatic segmentations were initially generated using the VibeSegmentator and subsequently refined manually to reduce the amount of included visceral fat. The Intra-observer reproducibility of the manual refinement was assessed after 3 months using Dice similarity score. SNR for both scan methods was quantified using a large water phantom. Mean segmented volume and mean pancreatic proton density fat fraction (PDFF) values between radial and Cartesian scans were compared. PDFF and volume changes between baseline and post-intervention were investigated for both techniques. Segmented pancreatic volumes and PDFF measurements demonstrated excellent agreement between the radial and Cartesian sequences (Volume: R = 0.97, ICC = 0.96; PDFF: R = 0.98, ICC = 0.98). Compared to the Cartesian scans, the radial scans exhibited a minor positive volume bias at higher pancreatic volumes (linear regression: 0.85x + 9.4 cm; mean volume bias: 5.8 cm, 95% LoA: -7.1 to 18.7 cm), alongside a proportional PDFF bias leading to slight overestimation at lower values and underestimation at higher values (linear regression: 0.88x + 2.1%; mean PDFF bias -0.2%, 95% LoA: -3.0 to 2.7%). Post-intervention, both datasets captured significant decreases in pancreatic PDFF (mean loss 2.3% ± 2.1%, Cartesian p < 0.001, radial p < 0.01) and volume (mean loss 8.4 cm ± 7.7 cm; both p < 0.001). The present study demonstrates the feasibility of a free-breathing radial stack-of-stars sequence for pancreatic fat quantification at 3T and its application in adults with obesity undergoing diet-induced weight loss.
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7. Quantifying the Transmit-Power Threshold for Reliable Passive Detuning of Inductively Coupled Wireless Resonators in MRI: A Phantom Study.
PMID:日期:2026-09-25This work develops and validates a practical method for quantifying the transmit-power threshold at which passive detuning of inductively coupled wireless resonators becomes reliable in MRI. All experiments were performed using phantoms. A near/far spatial signal ratio is computed from a series of gradient-echo (GRE) images acquired at different nominal flip angles. This ratio reveals ineffective detuning as a characteristic L-shaped curve whose inflection point marks the detuning threshold. The method was validated experimentally with wireless resonators incorporating different numbers of crossed diode pairs, at multiple static field strengths (3 and 7T), and with different scanner vendors. At 3T, the method produced consistent thresholds across Philips and GE scanners despite their different flip-angle thresholds. The proposed method provides a practical, straightforward tool for acceptance testing and quality assurance of wireless resonator safety in both clinical and research MRI settings.
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8. Predicting Glioma Survival From Intratumoral Vascular Topology: A Connectional Vessel Template Approach.
PMID:日期:2026-09-24Gliomas exhibit aberrant angiogenesis that drives tumor progression and therapeutic resistance. Susceptibility-weighted imaging (SWI) enables noncontrast visualization of intratumoral vasculature, but current approaches rely on summary metrics that overlook vascular topology. We developed a graph-based framework to model vascular networks from SWI and predict glioma survival. Between 2005 and 2020, 228 adults with histologically confirmed diffuse glioma (World Health Organization [WHO] Grades 2-4) who had undergone preoperative MRI were retrospectively screened. MRI was performed on 1.5- and 3-T scanners (Siemens Healthineers, Erlangen, Germany) including T2-weighted imaging (TR/TE 4000-6000/80-120 ms, FOV 220-256 mm, slice thickness 2-3 mm) and SWI (TR/TE 25-35/15-25 ms, FOV 200-240 mm, slice thickness 1.5-2 mm). Tumors were manually delineated on T2-weighted images and coregistered to SWI using advanced normalization tools (ANTs). Intratumoral vessels were extracted from SWI using the Frangi vesselness filtering and represented as graphs with nodes at branch points and endpoints and edges along vessel segments. Node-level, edge-level, and graph-level vascular features were processed by a GraphSAGE encoder to generate patient-specific embeddings, which were compared to a learnable population template within the connectional vessel template (CVT) framework to quantify individual vascular atypicality. A Cox proportional hazards head integrated graph embeddings, template deviation, and demographic features to output risk scores. Model performance was evaluated using 10-fold stratified cross-validation for progression-free survival (PFS) and overall survival (OS), with multivariable Cox regression and subgroup analyses across isocitrate dehydrogenase (IDH) mutation status and histological subtypes. A total of 193 patients were included (mean age 43.4 ± 14.0 years; 57.5% male). OS analysis included 182 patients (61 deaths), and PFS analysis included 170 patients (102 progression events). The CVT model achieved C-indices of 0.812 for PFS and 0.839 for OS with significant risk stratification (PFS log-rank p = 5.82 × 10; OS log-rank p = 1.17 × 10). The CVT risk score independently predicted PFS (HR 1.77, p < 0.001) and OS (HR 1.44, p < 0.001) beyond age and sex. Subgroup analyses demonstrated consistent PFS discrimination in IDH-wildtype tumors and glioblastoma (C-index 0.677) and strong OS prediction in IDH-mutant tumors (C-index 0.850). Graph-based modeling of SWI-derived vascular topology provides robust, independent prognostic information for glioma survival using a single noncontrast MRI sequence.
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9. Real-Time Neurofeedback Training to Modulate Glutamate-Glutamine Concentration Using Functional Magnetic Resonance Spectroscopy.
PMID:日期:2026-09-21Neurofeedback training is a procedure in which participants learn to modulate brain activity through their own efforts. Here, we designed a real-time neurofeedback training using functional magnetic resonance spectroscopy (fMRS) to modulate the concentration of glutamate, a major excitatory neurotransmitter, and its precursor glutamine (collectively referred to as Glx) in a volume-of-interest (VOI) located in the occipital lobes. During an induction phase participants employed a self-selected strategy to increase or decrease Glx concentration relative to a reference concentration measured prior to neurofeedback training. Participants were informed about their performance after the induction phase by displaying a disk in green for success or red for failure. The disk size indicated the magnitude of success or failure. The procedure was repeated over the course of 30 trials. Participants were randomly assigned to experimental and control groups (15 participants per group). The experimental group received veridical feedback about their success or failure in the induction phase. The control group received random feedback. Glx concentration in the VOI was measured using 2-s-long consecutive Point RESolved Spectroscopy (PRESS) scans in a 3-Tesla MRI scanner. The results showed that depending on group assignment, participants in the experimental group learned to increase or decrease Glx concentration over the course of training. No significant changes in Glx concentration were observed in the control group. These findings suggest that, with the help of veridical performance feedback, participants learned to modulate Glx concentration in the VOI in the desired direction over a relatively short period of time. fMRS-based neurofeedback training may complement existing neurofeedback approaches by targeting neurotransmitter-related processes.
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10. {"_":"The Impact of BOLD-Induced Linewidth Modulation on Functional H MRS Analysis.","sup":["1"]}
PMID:日期:2026-09-21Functional MRS can measure the neurometabolic response to neuronal activation, therapeutic interventions and changes in physiology. Substantial technical challenges currently present a barrier to reproducible findings and broader adoption by the neuroscientific community. One such challenge is the conflation between genuine metabolic changes and bias caused by subtle spectral lineshape changes associated with the BOLD response. Previous studies have demonstrated an approximately 1% bias for glutamate estimates at 7 T based on experimentally acquired data and a single conventional fitting algorithm. In this study, we use synthetic MRS data to estimate the bias for two conventional fitting methods (LCModel and ABfit-reg) at 3 and 7 T and evaluate the efficacy of dynamic lineshape adjustment, during preprocessing and fitting analysis stages, to reduce bias. Using the same dataset, we also explore the potential bias in 2D fitting approaches, comparing several fitting models implemented in FSL-MRS. The two conventional fitting methods, without explicit linewidth correction, had similar levels of bias (~1% for glutamate)-in good agreement with previous experimental studies at 7 T. Lineshape changes from the BOLD response cause similar bias in conventional and 2D fitting packages for 3 and 7 T data, resulting in an overestimation of metabolic changes associated with neuronal activation. This bias may be significantly reduced (< 0.2%) by incorporating a BOLD linewidth matching step for conventional analysis or by direct modelling for 2D analysis. We therefore recommend explicit BOLD lineshape correction or modelling for future task-based fMRS studies at 3 T and above.