NMR in Biomedicine最新文献

{"title":"GLOW: Gastric LOW-Rank Tensor-Based Motion Correction for Abdominal 4D MRI.","authors":"R Sclocco, J Coll-Font, B Kuo, V Napadow, C Nguyen","doi":"10.1002/nbm.70160","DOIUrl":"10.1002/nbm.70160","url":null,"abstract":"<p><p>Magnetic resonance imaging (MRI) applications to the study of gastric function in humans have started to incorporate dynamic volumetric imaging, thus calling for specialized approaches for motion correction. A method for retrospective respiratory motion correction in free-breathing, four-dimensional (4D) abdominal MRI is presented. Our gastric low-rank tensor-based (GLOW) algorithm uses a low-rank tensor (LRT) model to separate the temporal components that correspond to breathing motion from those related to gut motion, which are preserved due to being uncorrelated and spatially localized. As a proof-of-concept, the GLOW algorithm is applied to a human 4D gastric MRI dataset that includes data collected during both a fasted and fed state using a food-based contrast meal. This approach allows for a more robust and accurate assessment of gastric peristalsis. The GLOW algorithm represents an important step toward the effective application of noninvasive, naturalistic approaches to robustly and accurately evaluate gastric function via MRI.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 11","pages":"e70160"},"PeriodicalIF":2.7,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12651783/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145239474","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":"Automatic Identification of Potential Cellular Metabolites for Untargeted NMR Metabolomics.","authors":"Jiashang Chen, Angela Rao, Rajshree Ghosh Biswas, Ella J Zhang, Jonathan Xin Zhou, Evan Zhang, Zuzanna Kobus, Marta Kobus, Li Su, David C Christiani, David S Wishart, Leo L Cheng","doi":"10.1002/nbm.70131","DOIUrl":"10.1002/nbm.70131","url":null,"abstract":"<p><p>An organism's metabolic profile provides vital information pertaining to its physiology or pathology. To monitor these biochemical changes, Nuclear Magnetic Resonance (NMR) spectroscopy has found success in non-invasively observing metabolite changes within intact samples in an untargeted manner. However, biological samples are chemically complex, comprised of many different constituents (amino acids, carbohydrates, and lipids) at varying concentrations depending on physiological and pathological conditions. Due to the narrow spectral window of proton NMR, compound resonance frequencies can often overlap, making the identification and monitoring of metabolites difficult and time consuming, particularly when dealing with large numbers of samples. Here, we introduce a Python program (ROIAL-NMR) to systematically identify potential metabolites from defined proton NMR spectral regions-of-interest (ROIs), which are identified from complex biological samples (i.e., human serum, saliva, sweat, urine, CSF, and tissues) using the Human Metabolome Database (HMDB) as a reference platform. Briefly, for disease-versus-control studies, the program considers disease types and utilizes study-defined ROIs together with their differing intensity levels, according to sample types, in differentiating disease from control to propose potential metabolites represented by these ROIs in an output table. In this report, we illustrate the utility of the program with one of our recent studies, where we measured proton NMR spectra of serum samples taken from lung cancer (LC) patients, with and without Alzheimer's disease and related dementia (ADRD). The program successfully identified 88 metabolites, with 66 differentiating LC from control patients, and 80 distinguishing LC patients with ADRD from those without ADRD to provide important information regarding pathophysiology in complex biological samples.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 10","pages":"e70131"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445015/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144963145","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":"Accelerated Navigator for Rapid ∆B₀ Field Mapping for Real-Time Shimming and Motion Correction of Human Brain MRI.","authors":"Nutandev Bikkamane Jayadev, Jason Stockmann, Robert Frost, Nicolas Arango, Yulin Chang, André van der Kouwe, Ovidiu C Andronesi","doi":"10.1002/nbm.70126","DOIUrl":"10.1002/nbm.70126","url":null,"abstract":"<p><p>∆B₀ shim optimization performed at the beginning of an MR scan is unable to correct for ∆B₀ field inhomogeneities caused by patient motion or hardware instability during scans. Navigator-based methods have been demonstrated previously to be effective for motion and shim correction. The purpose of this work was to accelerate volumetric navigators to allow fast acquisition of the parent navigated sequence with short real-time feedback time and high spatial resolution of the ∆B₀ field mapping. A GRAPPA-accelerated 3D dual-echo EPI vNav was implemented on a 3 T Prisma MRI scanner. Testing was performed on an anthropomorphic head phantom and 11 human participants. vNav-derived ∆B₀ field maps with various spatial resolutions were compared to Cartesian-encoded gold-standard 3D gradient-echo ∆B₀ field mapping. ∆B₀ shimming was evaluated for the scanner's spherical harmonics shims and a custom-made AC/DC RF-receive/∆B₀-shim array. The performance of dual-echo and single-echo accelerated navigators was compared for tracking and updating ∆B₀ field maps during motion. Real-time motion and shim corrections for 2D MRI and 3D MRSI sequences were assessed in vivo with controlled head movement. Up to 8-fold acceleration of volumetric navigators (vNavs) significantly reduced geometric distortions and signal dropouts near air-tissue interfaces and metal implants. Acceleration allowed a flexible tradeoff between spatial resolution (2.5-7.5 mm) and acquisition time (242-1302 ms). Notably, accelerated high-resolution (5 mm) vNav was faster (378 ms) than unaccelerated low-resolution (7.5 mm) vNav (700 ms) and showed better agreement with 3D-GRE ∆B₀ field mapping with 5.5 Hz RMSE, 1 Hz bias, and [-10%, +10%] confidence interval. Accelerated vNavs improved 3D MRSI and 2D MRI in real-time motion and shim correction applications. Advanced shimming with spherical harmonic and shim array showed superior ΔB₀ correction, especially with joint shim optimization. GRAPPA-accelerated vNavs provide fast, robust, and high-quality ∆B₀ field mapping and shimming over the whole-brain. The accelerated vNavs enable rapid correction of ∆B₀ field inhomogeneities and faster acquisition of the navigated parent sequence. This methodology can be used for real-time motion and shim correction to enhance data quality in various MRI applications.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 10","pages":"e70126"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12409692/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144993121","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":"Multi-Parametric MRI for Early Detection of Renal Fibrosis and Evaluation of Therapeutic Effect of Asiatic Acid in an Experimental Rat.","authors":"Xueting Wang, Lihua Chen, Yujun Lu, Weijing Yan, Shuangshuang Xie, Jipan Xu, Zhandong Hu, Jinxia Zhu, Xiaoli Gong, Wen Shen","doi":"10.1002/nbm.70127","DOIUrl":"10.1002/nbm.70127","url":null,"abstract":"<p><strong>Objectives: </strong>Early diagnosis and timely treatment of renal fibrosis can improve the prognosis of patients with nephropathy. We aim to investigate the utility of multi-parametric MRI for evaluating early renal fibrosis and therapeutic efficacy in a rat model.</p><p><strong>Methods: </strong>Eighty-four male SD rats receiving tail vein injection of adriamycin doxorubicin (ADR) to establish renal fibrosis models were utilized. Twelve rats underwent pilot experiments to identify successful renal fibrosis modeling timepoints. Seventy-two were assigned to treated (AA) and untreated (ADR) groups, which were subdivided into AA-1 and ADR-1 groups (N = 6 each, underwent continuous MRI scanning at 0, 14, 21, 28, 35, 42d), AA-2 and ADR-2 groups (N = 30 each, 6 underwent MRI scanning at 0, 14, 21, 28, 35d). Repeated measures ANOVA was used to evaluate changes in parameters over time within continuous MRI scanning groups (AA-1 and ADR-1). Independent samples t test or Wilcoxon rank sum test were used to compare the differences of parameters among groups and different time points. Pearson's correlation coefficients were used to investigate relationships between renal blood flow (RBF), cortical and medullary T1, mean kurtosis (MK) and mean diffusivity (MD) values and the laboratory results, α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), Smad3, and Smad7.</p><p><strong>Results: </strong>T1 and MK values increased over time in all groups, while RBF and MD values decreased. Significant differences in all MRI parameters except medullary MK were observed between AA and ADR groups. RBF, MK, MD, and T1 values were significantly correlated with renal interstitial collagen area, α-SMA, TGF-β1, Smad3, and Smad7 (|r| = 0.5882 to 0.9756, p < 0.0001).</p><p><strong>Conclusion: </strong>Multi-parametric MRI can enable the detection of early microstructural and functional alterations in the kidney associated with renal fibrosis and provides a means to quantify the therapeutic efficacy of interventions.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 10","pages":"e70127"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144963123","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":"Relaxation-Selective Intravoxel Incoherent Motion Imaging of Microvascular Perfusion and Fluid Compartments in the Human Choroid Plexus.","authors":"Chenyang Li, Zhe Sun, Jiangyang Zhang, Yulin Ge","doi":"10.1002/nbm.70144","DOIUrl":"10.1002/nbm.70144","url":null,"abstract":"<p><p>The choroid plexus (ChP) is critical to the glymphatic system of the human brain through its primary function as the source of cerebrospinal fluid (CSF) production, which plays an important role in brain waste clearance. Developing noninvasive imaging techniques to assess ChP is crucial for studying its function and age-related neurofluid dynamics. In this study, we developed a relaxation-selective intravoxel incoherent motion (IVIM) technique to assess tissue and fluid compartments in the ChP of 83 middle-aged to elderly participants (age: 61.5 ± 17.1 years) and 15 young controls (age: 30.7 ± 2.9 years). Using a 3-T MRI scanner, we implemented T1- and T2-selective IVIM approaches, including Fluid-Attenuated Inversion Recovery IVIM (FLAIR-IVIM), LongTE-IVIM, and Vascular Space Occupancy-LongTE-IVIM (VASO-LongTE-IVIM), to measure diffusivity and volume fractions of fluid compartments in ChP. Our results showed that FLAIR-IVIM identified an additional interstitial fluid (ISF) compartment with free-water-like diffusivity in ChP. We then evaluated the aging effects on microvascular perfusion and ISF in ChP. Compared to younger adults, older adults exhibited increased ChP volume, reduced perfusion, decreased ISF volume fraction, and lower tissue diffusivity. Relaxation-selective IVIM may offer enhanced specificity for characterizing age-related changes in ChP structure and fluid dynamics.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 10","pages":"e70144"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12433185/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145054779","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":"Comparison of Brain Oxygen Metabolic Parameters Between Constrained qBOLD and Whole-Brain Oximetric Methods at Baseline and in Response to a Physiologic Stimulus.","authors":"Kathryn M Jaroszynski, Hyunyeol Lee, Michael C Langham, Felix W Wehrli","doi":"10.1002/nbm.70120","DOIUrl":"10.1002/nbm.70120","url":null,"abstract":"<p><p>The measurement of cerebral oxygen metabolism is important to understand and treat many disorders. Constrained quantitative BOLD (qBOLD) MRI is a calibration-free method for 3D voxel-wise whole-brain mapping of brain oxygen metabolism. This study aimed to evaluate the agreement between constrained qBOLD and global oximetry methods both at baseline and in response to a caffeine stimulus. Healthy volunteers (N = 10, age 30 ± 8 years) were imaged with constrained qBOLD, MOTIVE (metabolism of oxygen via T₂ and interleaved velocity encoding), dual-slice (DS), and single-slice (SS) OxFlow. Subjects were then given a 200 mg caffeine pill and imaged at 2-s temporal resolution immediately thereafter for 30 min by SS-OxFlow. After 30 min, the baseline protocol was repeated. Constrained qBOLD uses prior constraints to the QSM + qBOLD model to solve for voxel-wise oxygen extraction fraction (OEF). Quantification of cerebral blood flow (CBF) was accomplished for qBOLD from a separate measurement via pseudo-continuous arterial spin labeling (pCASL) to yield CMRO₂. Constrained qBOLD measured OEF (31 ± 5% gray matter [GM], 31 ± 6% white matter [WM] at baseline; 36 ± 7 GM, 35 ± 8 WM post-caffeine) was in good agreement with global oximetry methods DS-OxFlow (30 ± 4, 37 ± 5), SS-OxFlow (31 ± 4, 37 ± 4), and MOTIVE (32 ± 5, 39 ± 5). Temporal data showed a gradual increase in OEF with a commensurate reduction in CBF while the caffeine was taking effect. No significant change in CMRO₂ was noted with any of the techniques. Regional analysis of the basal ganglia, hippocampus, and thalamus found there was a significant increase in OEF post caffeine. The results indicate constrained qBOLD to yield OEF with negligible bias to global oximetry methods, both at baseline and post caffeine. The results also suggest that constrained qBOLD has the sensitivity to detect changes in oxygen metabolism due to a vasoconstrictive stimulus.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 9","pages":"e70120"},"PeriodicalIF":2.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12337088/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144817249","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":"Accelerated 3D qCEST of the Spine in a Porcine Model Using MR Multitasking at 3T.","authors":"Karandeep Cheema, Dante Rigo De Righi, Chushu Shen, Hsu-Lei Lee, Giselle Kaneda, Jacob Wechsler, Melissa Chavez, Pablo Avalos, Candace Floyd, Wafa Tawackoli, Yibin Xie, Anthony G Christodoulou, Dmitriy Sheyn, Debiao Li","doi":"10.1002/nbm.70122","DOIUrl":"10.1002/nbm.70122","url":null,"abstract":"<p><p>To assess lower back pain using quantitative chemical exchange saturation transfer (qCEST) imaging in a porcine model by comparing exchange rate maps obtained from multitasking qCEST with conventional qCEST. Use a permuted random forest (PRF) model trained on CEST-derived magnetization transfer ratio (MTR) and exchange rate (k_sw) features to predict Glasgow pain scores. Six Yucatan minipigs were scanned at baseline and at four post-injury time points (weeks 4, 8, 12, and 16) following intervertebral disc injury. Conventional qCEST imaging was performed at four B1 powers using a two-dimensional reduced field of view turbo spin-echo (TSE) sequence, with a total acquisition time of 24 min per slice. Multitasking steady-state (SS) CEST imaging was performed with pulsed saturation to achieve a steady state, acquiring 32 slices at 59 offsets for 4 B1 powers in 36 min. Exchange rate maps were generated using omega plot analysis, and CEST images were analyzed using a multi-pool fitting model to produce MTR and k_sw maps. Permuted random forest (PRF) model was trained on MTR and k_sw values to predict pain scores. Modic changes were assessed using T2-weighted MR images. The Pearson correlation coefficient between exchange rate maps from multitasking qCEST and conventional qCEST was 0.82, demonstrating strong agreement. The 3D qCEST (SS-CEST) technique effectively differentiated between healthy and injured discs, with injured discs exhibiting significantly higher k_sw values. Using MTR and k_sw, the PRF model achieved 80% accuracy in predicting pain scores disc-by-disc, outperforming the correlation with Modic changes (r = 0.45, p < 0.05); with a Cohen's Kappa of 0.4. 3D steady-state qCEST with whole-spine coverage can be done at 3T within 32 min using MR Multitasking (acceleration factor of 22), and qCEST-derived biomarkers (MTR and k_sw) can predict pain scores with an accuracy of 80%.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 9","pages":"e70122"},"PeriodicalIF":2.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144859399","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":"Improved Strength Prediction Combining MRI Biomarkers of Muscle Quantity and Quality.","authors":"Valentina Mazzoli, Yael Vainberg, Mary E Hall, Marco Barbieri, Jessica Asay, Julie Muccini, Jarret Rosenberg, Feliks Kogan, Scott Delp, Garry E Gold","doi":"10.1002/nbm.70112","DOIUrl":"10.1002/nbm.70112","url":null,"abstract":"<p><p>Muscle strength declines with aging at a faster rate compared with muscle mass, suggesting that not only muscle quantity but also muscle quality and architecture are age-dependent. This study tested the hypothesis that quantitative MRI (qMRI)-derived biomarkers of muscle quality (fractional anisotropy [FA], radial diffusivity [RD], axial diffusivity [AD], fat fraction [FF], and T₂ relaxation time) and architecture (fascicle length) could improve the prediction of skeletal muscle strength over muscle mass alone. We recruited 24 adults (12 female, age range 30-79 years). Muscle mass was estimated as the volume and cross-sectional area (CSA) of the quadriceps. FA, RD, and AD parameters, together with fascicle length for the rectus femoris (RF) and vastus lateralis (VL), were derived from diffusion tensor imaging (DTI), and muscle-T₂ was calculated from a multi-echo spin echo sequence. FF was determined using the Dixon approach. CSA values were combined with FF to calculate the lean CSA. Isometric, eccentric, and concentric knee extension torques were measured for the left and right leg using an isokinetic dynamometer. The univariable assessment of torque was performed using a linear regression. The statistical significance of adding qMRI parameters to the torque prediction models was tested using a mixed-effect regression. The best univariable predictor of isometric, eccentric, and concentric torque was lean CSA. Adding FA, RF fascicle length, and VL fascicle length to the model improved the prediction of concentric torque compared with CSA alone. The addition of FA, T₂, RD, RF fascicle length, and VL fascicle length improved the prediction of eccentric torque over CSA alone. The addition of FF was not significant within the model. Our results confirmed the hypothesis that the inclusion of qMRI parameters of muscle composition and architecture leads to higher R² coefficients for the prediction of muscle strength compared with models solely based on muscle quantity. These observations support the utility of qMRI for future research on sarcopenia prediction and management.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 9","pages":"e70112"},"PeriodicalIF":2.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12778366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144794976","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":"Improved IVIM Imaging in Adolescent Crohn's Disease Using Dual-Echo EPI Distortion and Motion Correction.","authors":"Cemre Ariyurek, Lina Lu, Georgios Antonios Sideris, Valentina Valencia Ferrer, Liam Timms, Serge Didenko Vasylechko, Onur Afacan, Sila Kurugol","doi":"10.1002/nbm.70117","DOIUrl":"10.1002/nbm.70117","url":null,"abstract":"<p><p>Diffusion-weighted imaging (DWI) during MR enterography helps identify bowel inflammation in Crohn's disease (CD). However, image quality is compromised by geometric distortions from B₀ field variations and physiological motion, making it challenging for radiologists to correlate findings between DWI and structural images. Traditional correction methods using reversed polarity scans are ineffective due to motion between acquisitions, which limits accurate estimation of intravoxel incoherent motion (IVIM) parameters. We propose a dual-echo echo-planar imaging (EPI) method that retrospectively corrects both geometric distortions and motion in 3T bowel DWI by accounting for field changes during peristalsis and breathing. We added a 5- to 7-min dual-echo EPI DW sequence (eight b-values, six directions) to the clinical MR enterography protocol of 21 patients with suspected CD at 3T MRI. Distortion correction was applied based on dynamically estimated fields from dual-echo DWI, followed by intra-volume registration between odd-even slices and inter-volume registration for motion correction. Two experienced board-certified radiologists evaluated the severity of the disease using simplified magnetic resonance index of activity (MaRIA) scores. Based on their consensus scores, patients were categorized into three groups: no active disease (MaRIA score = 0), active disease (MaRIA score = 1-2), and severe disease (MaRIA score = 3-5). The proposed DWI correction pipeline improved DWI/T₂-weighted image Dice similarity from 0.73 to 0.89, enabling better correlation of findings between structural and DW-MR images and enhancing DWI's clinical value. Corrected IVIM parameters showed stronger correlations with MaRIA scores (D: ρ = -0.93; f: ρ = -0.94, p < 0.001) compared to uncorrected parameters (D: ρ = -0.68, p = 0.001; f: ρ = -0.35, p = 0.118). Diagnostic sensitivity increased from 0.44 to 0.89, while parameter uncertainty decreased from 35.58% to 19.31% for D and 63.48% to 40.40% for f (p < 0.001). These improvements strengthen quantitative IVIM imaging for CD assessment, potentially reducing reliance on contrast imaging while offering enhanced tissue perfusion and diffusion insights.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 9","pages":"e70117"},"PeriodicalIF":2.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12392371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144835877","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":"HSGDNet: Hybrid Synthetic-Data-Guided Deep Learning With NLS Refinement for Fast Multi-Component T1ρ Knee Mapping.","authors":"Dilbag Singh, Ravinder R Regatte, Marcelo V W Zibetti","doi":"10.1002/nbm.70107","DOIUrl":"10.1002/nbm.70107","url":null,"abstract":"<p><p>Multi-component T1ρ mapping of the knee joint using nonlinear least squares (NLS)-based methods is usually a computationally intensive task, limiting its application to only a few voxels in the knee joint. Deep learning (DL) is a computationally fast alternative, but requires a large amount of training data. We propose the Synthetic data-Guided supervised DL Network (SGDNet) that utilizes synthetically generated data for training, eliminating the need for large datasets of T1ρ maps. Initially, residual connections are added to improve gradient flow and stabilize training. A self-attention module is also integrated into the SGDNet to obtain more accurate estimated relaxation maps. Additionally, to ensure both parameter fidelity and data consistency, we employ a customized loss function that penalizes discrepancies between actual and predicted T1ρ values as well as between measured and simulated MR signals. To combine speed and precision, we further introduce HSGDNet, a hybrid approach that uses SGDNet's outputs as initialization for a few NLS iterations. Extensive experimental analysis reveals that HSGDNet outperforms the competing methods by achieving average error reductions of 91.4%, 31.5%, and 36.0% for mono-exponential (ME), stretched-exponential (SE), and bi-exponential (BE) components, respectively. HSGDNet accelerates whole-knee T1ρ fitting over NLS by approximately 67.4 × for ME, 53.9 × for SE, and 42.3 × for BE. Finally, to evaluate robustness under pathological and protocol variations, we validate HSGDNet on an early osteoarthritis (EOA) dataset acquired with distinct spin-lock times (TSLs) values. Overall, HSGDNet establishes itself as an efficient method for rapid, precise, and robust multi-component T1ρ mapping in the knee joint.</p>","PeriodicalId":19309,"journal":{"name":"NMR in Biomedicine","volume":"38 9","pages":"e70107"},"PeriodicalIF":2.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12961685/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144743338","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}