Magnetic Resonance Materials in Physics, Biology and Medicine最新文献

{"title":"Simulation of realistic brain phantoms for susceptibility tensor imaging.","authors":"Nestor Muñoz, Carlos Milovic, Christian Langkammer, Cristian Tejos","doi":"10.1007/s10334-026-01402-2","DOIUrl":"https://doi.org/10.1007/s10334-026-01402-2","url":null,"abstract":"<p><strong>Objective: </strong>To propose three Susceptibility Tensor Imaging (STI) brain phantoms as ground truth for evaluating STI reconstruction algorithms: two derived from STI data and the one from Diffusion Tensor Imaging (DTI).</p><p><strong>Methods: </strong>The eigenvalues were generated through a pipeline inspired by the Quantitative Susceptibility Mapping (QSM) Reconstruction Challenge 2.0. An eigendecomposition was applied to an acquired susceptibility tensor, and literature-reported mean eigenvalues were assigned to 13 distinct brain regions. Fractional Anisotropy (FA) maps provided realistic spatial texture in the eigenvalues. Eigenvectors were obtained from DTI and two STI reconstructions: a Least-Squares algorithm and Diffusion Regularized STI (DRSTI). Microstructural simulations were incorporated into white matter regions. Phantom behavior was tested in three experiments: (i) anisotropic susceptibility assessment using QSM at different orientations; (ii) STI reconstructions across five algorithms with varying orientation numbers; and (iii) reconstructions under different angular rotation ranges.</p><p><strong>Results: </strong>The phantoms showed strong contrast in subcortical regions and realistic microstructural patterns. Algorithmic performance trends matched prior reports, with reduced errors as orientation count and rotation range increased.</p><p><strong>Discussion: </strong>Three open-source, in-silico STI brain phantoms were developed and validated as ground truth references for the evaluation of current and future STI reconstruction algorithms.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795210","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":"Mapping concussion-induced cerebellar injury: a personalized approach using diffusion tensor imaging (DTI).","authors":"Nicholas Simard, Michael D Noseworthy","doi":"10.1007/s10334-026-01401-3","DOIUrl":"https://doi.org/10.1007/s10334-026-01401-3","url":null,"abstract":"<p><strong>Objective: </strong>We investigated the potential of diffusion tensor imaging (DTI) in identifying alterations in cerebellar white matter (WM) in concussion patients. We hypothesized that DTI, combined with a Z-score analysis approach, could provide personalized assessment of cerebellar changes in these patients.</p><p><strong>Materials and methods: </strong>Fifty-one mTBI patients (25 females, age: 40.5 ± 11.7 years and 26 males, age: 45.0 ± 14.1 years) and 2700 healthy age/sex/vendor-matched controls were analyzed in this study. DTI data analysis focused on scalar metrics fractional anisotropy (FA) and mean diffusivity (MD). A Z-score approach was used to identify subject-specific deviations, while statistical models (linear regression, random forests, hierarchical clustering) compared the sensitivity of Z-scores and the Post-Concussion Symptom Scale (PCSS) in capturing individualized differences.</p><p><strong>Results: </strong>Significant cerebellar DTI abnormalities were found in the concussion group. Z-score analysis showed higher sensitivity to cerebellar regions associated with balance and sleep. Statistical models revealed distinct patterns by age, sex, region, and symptoms, underscoring the value of personalized analysis and the subjectivity that remains in existing assessments like the PCSS.</p><p><strong>Discussion: </strong>The combination of DTI and Z-score methods provides a promising framework for personalized detection of cerebellar changes in mTBI, potentially improving diagnostic accuracy and enabling more targeted interventions.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795226","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":"Comparative analysis of ²³Na T₁ and T₂^* relaxation times in healthy muscle tissue at 3 and 7 T.","authors":"Nour Zeitouni, Laurent Ruck, Lena V Gast, Michael Uder, Arnd Dörfler, Armin M Nagel, Teresa Gerhalter","doi":"10.1007/s10334-026-01404-0","DOIUrl":"https://doi.org/10.1007/s10334-026-01404-0","url":null,"abstract":"<p><strong>Objective: </strong>While most sodium (²³Na) MRI studies focus on apparent tissue sodium concentration (aTSC), longitudinal (T₁) and transverse (T₂*) relaxation times may provide additional microstructural and physiological information. This study aimed to establish reference values for ²³Na T₁ and bi-exponential T₂* in human lower-leg muscle at 3 T and 7 T, evaluate methodological factors influencing T₂* quantification, and assess the reproducibility of aTSC.</p><p><strong>Methods: </strong>Twenty healthy volunteers underwent ²³Na MRI of the lower leg at 3 T and 7 T using 3D stack-of-stars UTE acquisitions. T₂* was quantified from multi-echo data using bi-exponential fitting with both fixed and free short-component fractions. T₁ was measured with a saturation-recovery approach. aTSC was calculated using calibration phantoms.</p><p><strong>Results: </strong>T₁ increased with field strength (3 T 26.5 ± 2.0 ms; 7 T 28.1 ± 1.7 ms), while long T₂* decreased (3 T T₂_l* 20.5 ± 2.9 ms; 7 T T₂_l* 18.4 ± 2.5 ms). T₂* estimation depended on echo sampling and fitting assumptions. Mean aTSC was 17.5 ± 1.7 mM at 3 T and 18.5 ± 1.7 mM at 7 T, with a reproducibility coefficient of variation of 4.1%. Moderate positive correlations between field strengths were observed for short T₂*, its fraction, T₁, and aTSC.</p><p><strong>Conclusions: </strong>This study provides reference values for sodium T₁ and bi-exponential T₂* relaxation in human skeletal muscle at 3 T and 7 T and demonstrates high reproducibility of aTSC across field strengths.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795159","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":"Evaluation of a modular flexible coil for thoracic outlet syndrome MRI at 3 T.","authors":"Catherine Truong, Bouchra Assabah, Pedro Teixeira, Audrey Kirsch, Pierre-André Vuissoz, Romain Gillet, Elmar Laistler, Jacques Felblinger, Lena Nohava, Karyna Isaieva","doi":"10.1007/s10334-026-01410-2","DOIUrl":"https://doi.org/10.1007/s10334-026-01410-2","url":null,"abstract":"<p><p>Thoracic outlet syndrome (TOS) results from compression of neurovascular structures. Dynamic MRI may enhance diagnostic accuracy; however, conventional rigid coils are suboptimal for imaging during functional maneuvers. This study compared a custom-built flexible modular coil (ModFlex) with a conventional torso coil, focusing on the interscalene (ISS) and costoclavicular spaces (CCS). Nine healthy volunteers participated in 3 T TOS MRI using both coils. The signal-to-noise ratio (SNR) was calculated in two regions of interest (ISS and CCS). Additionally, g-factors were evaluated for simulated GRAPPA parallel imaging factors from 3 to 6. Two clinicians visually rated T1-weighted sagittal images to assess ModFlex coil performance. Quantitative data were compared using the Wilcoxon signed-rank and the ranks with the sign test. The ModFlex demonstrated a significantly higher SNR in the CCS (+ 39%, p = 0.004), a trend toward higher SNR in the ISS (+ 17%, p = 0.098), and significantly lower g-factors (i.e., higher parallel imaging performance) across all acceleration levels (p < 0.008). The clinicians' evaluation was generally consistent with quantitative findings, although not conclusive. GRAPPA acceleration provided better image quality than SMS (p = 0.008). Overall, modular flexible coils support faster, higher-quality dynamic TOS MRI protocols, potentially improving diagnostic reliability, and patient comfort.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795134","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":"Reproducibility of T2 relaxation time mapping in a phantom and human knee articular cartilage.","authors":"Henri P P Leskinen, Nea Pulkkinen, Antti Aarnio, Amir Esrafilian, Teija Sainio, Eveliina Lammentausta, Ville Kantola, Victor Casula, Simo Ojanen, Jari Rautiainen, Petri Kaurola, Mimmi K Liukkonen, Jarkko Iivarinen, Mikko J Nissi, Jari Heikkinen","doi":"10.1007/s10334-026-01406-y","DOIUrl":"https://doi.org/10.1007/s10334-026-01406-y","url":null,"abstract":"<p><strong>Objective: </strong>To quantify the reproducibility of knee articular cartilage T2 across a wide range of MR systems.</p><p><strong>Materials and methods: </strong>The reproducibility of T2 relaxation time mapping was assessed by measuring the knee of a volunteer (n_1.5 T = 22, n_3T = 13) and a System Standard 130 phantom (n_1.5 T = 19, n_3T = 12) in 38 different clinical MRI scanners at 16 imaging sites. Root-mean-square coefficient of variation (CV_RMS) was used to quantify the reproducibility of T2 at the selected knee cartilage regions of interest (ROI) and the phantom T2 array vials.</p><p><strong>Results: </strong>Low-to-moderate inter-scanner variation for the knee ROIs, CV = 2.2% to 22.8%, CV_RMS,1.5 T = 9.3%, CV_RMS,3 T = 11.0%, was observed. The phantom measurements showed low inter-scanner variation (CV_{RMS, 1.5 T} = 4.7%, CV_{RMS, 3 T} = 2.4%) on the typical cartilage T2 range.</p><p><strong>Discussion: </strong>Reproducibility of quantitative T2 can vary between healthcare facilities and scanners but also between the cartilage compartments. The variation is sufficiently small to consider T2 mapping reproducible. Phantom measurements support this result.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795190","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":"Memory-efficient image reconstruction using diffusion models for accelerated 3D non-Cartesian UTE imaging.","authors":"Jonas Petersen, Stefan Sommer, Thomas Küstner","doi":"10.1007/s10334-026-01403-1","DOIUrl":"https://doi.org/10.1007/s10334-026-01403-1","url":null,"abstract":"<p><strong>Purpose: </strong>Accelerated 3D non-Cartesian MRI presents unique challenges in balancing high-resolution reconstruction with computational and memory constraints. In this work, a novel, memory-efficient image reconstruction framework using score-based diffusion models tailored for highly undersampled 3D radial UTE acquisitions is proposed.</p><p><strong>Methods: </strong>The method leverages a volumetric extension of the NCSN++ architecture with efficient NUFFT operations and integrates a conjugate gradient-based data consistency mechanism within a predictor-corrector sampling scheme.</p><p><strong>Results: </strong>This approach enables robust and high-fidelity reconstructions from as few as 4000 spokes-representing up to 50 × undersampling relative to Nyquist. Generalizable performance across knee, ankle, and out-of-distribution shoulder datasets is demonstrated and superior image quality compared to compressed sensing and conventional iterative methods, especially at high acceleration factors is shown.</p><p><strong>Conclusion: </strong>The proposed framework marks a significant step toward practical deployment of diffusion models in non-Cartesian MRI reconstruction.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795224","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":"Dynamic glucose-enhanced MRI in brain tumors.","authors":"Anina Seidemo, Xiang Xu, Ronnie Wirestam, Pia C Sundgren, Peter C M van Zijl, Linda Knutsson","doi":"10.1007/s10334-026-01396-x","DOIUrl":"https://doi.org/10.1007/s10334-026-01396-x","url":null,"abstract":"<p><p>Dynamic glucose-enhanced (DGE) MRI is an emerging imaging technique that provides information on sugar uptake with contributions from delivery (perfusion), transport (membrane permeability), and metabolism in vivo. DGE MRI contrast reflects changes in water magnetization caused by changes in sugar concentration, which can be detected through chemical exchange between water protons and sugar hydroxyl protons. Such contrast can be visualized using chemical exchange-sensitive saturation transfer (CEST), on- and off-resonance spin-lock (CESL), and <math><msub><mi>T</mi> <mn>2</mn></msub> </math> relaxation-based approaches. These methods enable the use of biodegradable sugars as contrast agents, which are expected to have fewer side effects than conventional gadolinium-based MRI contrast agents and are more affordable and environmentally friendly. In this review, part of the special issue \"New MR imaging techniques in Oncology,\" we provide an overview of DGE MRI and its potential applications in brain tumor imaging. We introduce the physical principles underlying the contrast mechanisms and summarize current acquisition strategies and post-processing approaches, including quantification and kinetic modeling. Technical challenges such as small signal changes, motion sensitivity, and inhomogeneities in static ( <math><msub><mi>B</mi> <mn>0</mn></msub> </math> ) and radiofrequency ( <math><msub><mi>B</mi> <mn>1</mn></msub> </math> ) magnetic fields are discussed. Special attention is given to glucose physiology and pharmacokinetics, including administration methods. Throughout, we summarize preclinical and early patient studies in brain tumors and compare DGE MRI with other functional and molecular imaging techniques using MRI and PET. Finally, we discuss future directions for clinical translation, emphasizing the need for standardized protocols and improved acquisition and post-processing strategies.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795214","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":"Relaxivity comparison of Gadoteric acid and Gadopiclenol using clinical and reference MRI sequences at 1.5 T.","authors":"Gauthier Binninger, Jean-Philippe Dillenseger, Laurent Barantin, Rémi Hattat, Sarah Catoen, Philippe Robert, Laurent Arnould, Baptiste Morel","doi":"10.1007/s10334-026-01405-z","DOIUrl":"10.1007/s10334-026-01405-z","url":null,"abstract":"<p><strong>Introduction: </strong>Gadolinium-based contrast agents (GBCAs) exhibit variable relaxivity, and accurate relaxivity assessment is essential both for technical characterization and for optimizing clinical protocols. While reference relaxometry sequences are considered the gold standard for T1 and T2 quantification, clinical T1/T2 mapping techniques are used in routine MRI despite known limitations. This study aimed to compare relaxivity measurements obtained with reference relaxometry and clinically available T1/T2 mapping sequences at 1.5 T, using Gadoteric acid and Gadopiclenol as test agents.</p><p><strong>Methods: </strong>A phantom containing multiple dilutions of Gadoteric acid (0.1-3.0 mM) and Gadopiclenol (0.05-1.5 mM) was scanned on a routine 1.5 T MRI system. T1 relaxivity was assessed with spin-echo, inversion recovery, and clinical mapping techniques, while T2 relaxivity was measured with multi-echo spin echo and clinical mapping protocols. Relaxivity constants were derived from linear fitting. Water and oil vials were included as reference samples to verify signal stability and fitting consistency.</p><p><strong>Results: </strong>Clinical mapping sequences yielded relaxivity values broadly consistent with reference methods, although their performance varied depending on the T1/T2 range. MP2RAGE showed non-physiological behavior at high gadolinium concentrations (very short T1 values), MOLLI exhibited reduced precision for the shortest T1 values, and the cardiac T2 mapping sequence had to be excluded due to inconsistent measurements in vials with very short T2 values. As expected, Gadopiclenol demonstrated higher r₁ and r₂ relaxivity than Gadoteric acid across all techniques.</p><p><strong>Conclusion: </strong>Clinical T1/T2 mapping sequences can provide reliable relaxivity estimates over most of the relevant range but show predictable limitations at extreme relaxation times. Reference relaxometry remains the most accurate approach. Using two contrast agents with different relaxivity profiles allowed a robust comparison of the strengths and limitations of clinical versus reference relaxometry techniques. Gadopiclenol exhibited higher relaxivity than Gadoteric acid under phantom conditions, consistent with its potential for dose-efficient protocols, although any clinical dose reduction requires dedicated in vivo validation.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148727721","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":"An external reference to enable quantitative susceptibility mapping (QSM) in absolute terms: theoretical considerations, simulations, and experimental evaluation.","authors":"Anna Lundberg, Ronnie Wirestam, Jimmy Lätt, Linda Knutsson, Emelie Lind","doi":"10.1007/s10334-026-01378-z","DOIUrl":"https://doi.org/10.1007/s10334-026-01378-z","url":null,"abstract":"<p><strong>Objective: </strong>Quantitative susceptibility mapping (QSM) is a semi-quantitative method, i.e., only differences in magnetic susceptibility can be quantified. The lack of a stable internal reference hampers longitudinal and systematic comparisons among subjects. In this study, a phase-based approach, enabling the use of an external reference, is proposed.</p><p><strong>Materials and methods: </strong>By modeling the object geometry and analyzing the object-induced magnetic field distortion in the external reference, a relationship between the manifested phase and susceptibility was established. The proposed theoretical framework was validated using a numerical head phantom and 3 T MRI measurements, investigating five phantoms with different concentrations of gadolinium and one healthy volunteer. The derived theoretical relationship, together with accurate phase measurements, provided the absolute mean magnetic susceptibility of the object of interest.</p><p><strong>Results: </strong>Excellent accuracy was demonstrated in the numerical head phantom. Encouraging, although somewhat underestimated, susceptibility results were obtained for the MRI phantom measurements. The relationship between measured and theoretical susceptibility values showed excellent correlation (r = 0.98, p = 0.004). The in vivo measurement yielded an absolute mean susceptibility of 0.02 ppm (relative to water).</p><p><strong>Discussion: </strong>Feasibility and proof of concept were demonstrated, and the approach, in combination with conventional QSM, offers an alternative reference solution with potential to facilitate absolute QSM maps.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678478","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":"Machine learning assisted prediction of cartilage histology using MR fingerprinting - a preliminary study.","authors":"Ville Kantola, Olli Nykänen, Victor Casula, Ville-Pauli Karjalainen, Martijn A Cloos, Riccardo Lattanzi, Mikko J Nissi, Miika T Nieminen","doi":"10.1007/s10334-026-01397-w","DOIUrl":"https://doi.org/10.1007/s10334-026-01397-w","url":null,"abstract":"<p><strong>Introduction: </strong>Prediction of cartilage structural properties through MRI could allow earlier detection of joint pathologies, such as osteoarthritis.</p><p><strong>Materials & methods: </strong>Bovine patellar cartilage samples (n = 12) were imaged using magnetic resonance fingerprinting, followed by histological examination of proteoglycan content and collagen fiber anisotropy. The relaxation time maps and raw signal data were then used for training Gaussian process regression (GPR) models to predict the histology results.</p><p><strong>Results: </strong>Proteoglycan content was predicted by the GPR models with high accuracy (median r = 0.81, σ = 0.08 and NRMSE = 11.7%). Predictions performed using raw MRF data outperformed those done using qMRI maps. Collagen fiber anisotropy predictions found only weak correlation (median r = 0.40, σ = 0.25 & NRMSE = 26.4%) and no significant difference was seen between models trained on raw MRF or relaxation time maps.</p><p><strong>Discussion: </strong>These findings indicate that noninvasive prediction of proteoglycan content in cartilage from MRF measurements using a 3 T clinical scanner is feasible, holding promise for future clinical applications. Collagen fiber anisotropy could not be reliably estimated with the current setup. GPR-based prediction models were found to outperform reference linear models using the same prediction data.</p>","PeriodicalId":18067,"journal":{"name":"Magnetic Resonance Materials in Physics, Biology and Medicine","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148670008","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}