Magnetic Resonance in Medicine最新文献

{"title":"A Comparison of Tissue Property Values Estimated Using Conventional Cardiac MRF and MT-Cardiac MRF.","authors":"Sydney Kaplan, Zexuan Liu, Jesse Hamilton, Shaihan Malik, Chaitanya Madamanchi, Venkatesh Murthy, Scott Swanson, Nicole Seiberlich","doi":"10.1002/mrm.70470","DOIUrl":"10.1002/mrm.70470","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the impact of explicitly modeling Magnetization Transfer (MT) during reconstruction of cardiac Magnetic Resonance Fingerprinting (cMRF) maps on T₁ and T₂ quantification.</p><p><strong>Methods: </strong>cMRF data were reconstructed using two dictionaries: a conventional cMRF dictionary that ignores MT processes, and an MT-cMRF dictionary modeling T₁ and T₂ of the free water pool (T_1f and T_2f, respectively), as well as the bound pool fraction (BPF) as free parameters. Measurements which include MT processes were assessed in simulation and phantom to ensure that T_1f, T_2f, and BPF could accurately be measured using cMRF. cMRF data were then collected in 14 healthy subjects to measure T₁/T_1f, T₂/T_2f, and BPF in normal myocardium. Finally, cMRF data were acquired in five patients with known or suspected myocardial scar at 1.5T, and tissue property maps both ignoring and including MT were generated. Linear discriminant analyses (LDA) were performed to assess differences in tissue property values between scar and remote myocardium.</p><p><strong>Results: </strong>MT-cMRF showed excellent agreement with ground truth simulations (RMS error = 2.4% ± 3.9%) and phantom measurements (R² = 0.99). Values measured with MT-cMRF in healthy subjects (T_1f = 1137 ± 72 ms, T_2f = 42.8 ± 4.2 ms, BPF = 8.2% ± 1.2%) were significantly different than conventional cMRF (T₁ = 947 ± 75 ms, T₂ = 41.5 ± 3.9 ms). T_1f/T_2f and T_2f/BPF from MT-cMRF demonstrated higher LDA accuracy (82.4% and 86.1%) in discriminating scar from healthy tissue than T₁ and T₂ from conventional cMRF (61.8%).</p><p><strong>Conclusion: </strong>Incorporating MT modeling into cMRF results in improved T_1f and T_2f quantification compared to conventional modeling and enables BPF measurement. Native MT-cMRF T_1f, T_2f, and BPF values showed differences between scar and healthy myocardium.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1806-1813"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419325/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148361237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of an 8-Channel Transmit 32-Channel Receive 11.7T Head Coil and Evaluation of SNR Gains.","authors":"Son Chu, Jeslin Parackal Issac, Caroline Le Ster, Alexis Amadon, Vincent Gras, Paul-François Gapais, Rüdiger Stirnberg, Nicolas Boulant, Shajan Gunamony","doi":"10.1002/mrm.70473","DOIUrl":"10.1002/mrm.70473","url":null,"abstract":"<p><strong>Purpose: </strong>To design and develop an 8-channel transmit 32-channel receive 11.7T head coil for the strongest human MRI scanner to date, demonstrate safety, and evaluate signal-to-noise ratio (SNR) gains compared to 7T, the most used ultra-high-field (UHF) platform.</p><p><strong>Methods: </strong>The transmit array design incorporated a folded-end radiofrequency (RF) shield to mitigate wave propagation in the scanner bore. The receive array consisted of 32-overlapped loops constructed on a helmet size-matched with the industry standard 7T head coil. The transmit array was characterized using B₁ ⁺ mapping and MR thermometry, whereas the receive array performance was evaluated by measuring SNR at 7T and 11.7T using a lightbulb-shaped phantom filled with a tissue equivalent solution.</p><p><strong>Results: </strong>Loss due to wave propagation was 4.5% of the input power for the chosen RF shield. The mean magnitude of the complex correlations between the simulated and measured single channel B₁ ⁺ maps was 94%, which highlights minimal interaction between the transmit and receive arrays. An SNR gain of three-fold was achieved in the phantom centre. In the periphery, representing the cortex, the SNR gain was 2.65-fold, and the average gain over the whole volume was a factor of 2.69. The g-factors of the 11.7T array were lower than the reference 7T coil due to the distinct coil sensitivities at higher frequency.</p><p><strong>Conclusion: </strong>We report substantial SNR gains over the whole volume at 11.7T using a fully overlapped 32-channel loop array. The central SNR gain of B₀ ^2.14 agrees with the theoretical prediction, while we also gain supra-linearly in the periphery.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"2004-2018"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419043/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148317931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Locally Linearized Approximation of RF Pulse Propagators for Faster Simulation of Magnetization Dynamics With Slice Profile Effects in 2D MR Fingerprinting.","authors":"Nikolai J Mickevicius","doi":"10.1002/mrm.70462","DOIUrl":"10.1002/mrm.70462","url":null,"abstract":"<p><strong>Purpose: </strong>The objective for this study is to decrease the computation time of magnetic resonance fingerprinting dictionary computations that include slice profile effects.</p><p><strong>Theory and methods: </strong>A locally linearized approximation to RF pulse propagators across RF scaling factors was derived and used to decrease the computational burden of MRF dictionary computation. MR fingerprinting phantom experiments were carried out at 3T to assess the practical feasibility of using dictionaries approximated with the proposed approach.</p><p><strong>Results: </strong>Using linearizations at 10 <math> <mrow> <msubsup><mrow><mi>B</mi></mrow> <mrow><mn>1</mn></mrow> <mrow><mo>+</mo></mrow> </msubsup> </mrow> </math> scaling factors produced root mean square differences in estimated <math> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>1</mn></mrow> </msub> </mrow> </math> and <math> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>2</mn></mrow> </msub> </mrow> </math> of 1.17% and 1.98%, respectively, between dictionaries generated using a full Bloch simulation and the locally linear approximation while decreasing computation time by a factor of 10.</p><p><strong>Conclusion: </strong>The proposed locally linear approximation significantly accelerates slice-profile-aware MRF simulations while maintaining high accuracy, enabling practical incorporation of realistic RF pulse effects into large-scale dictionary computations.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1909-1915"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419243/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148205348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fourier Shell Analysis: k-Space-Based Metrics for Assessing Super-Resolution in 4D Flow MRI.","authors":"Luuk Jacobs, Pietro Dirix, Sebastian Kozerke","doi":"10.1002/mrm.70478","DOIUrl":"10.1002/mrm.70478","url":null,"abstract":"<p><strong>Purpose: </strong>To support the emerging field of super-resolution (SR) in 4D flow MRI by proposing Fourier shell analysis to disentangle resolution enhancement from denoising effects during evaluation.</p><p><strong>Methods: </strong>A thoracic aortic 4D flow MRI dataset was synthesized with various degrees of stenosis, providing ground truth flow fields generated using computational fluid dynamics and MRI-specific downsampling to generate paired low- and high resolution (LR/HR) 4D Flow MRI data. To address potential confounding of resolution enhancement versus denoising effects when using current image-based error metrics, a k-space-based Fourier shell analysis is proposed to compare SR results to HR references using multiple concentric shells with increasing spatial frequency radii in k-space. To demonstrate its value, the performance of a deep learning SR network (4DFlowNet) with two degrees of transfer learning is compared for three different signal-to-noise ratios (SNR) of <math><mrow><mi>∞</mi></mrow> </math> , 20, and 5.</p><p><strong>Results: </strong>It is demonstrated that Fourier shell analysis is superior in isolating and quantifying resolution enhancement compared to image-based metrics. When comparing SR performance of 4DFlowNet with different degrees of transfer learning, Fourier shell analysis isolates resolution enhancement more clearly relative to image-based normalized root-mean-square-error analysis (absolute relative mean paired difference of 160.3% vs. 13.1% for noiseless data, 92.3% vs. 12.4% for SNR of 20, and 300.0% vs. 10.2% for SNR of 5, respectively).</p><p><strong>Conclusion: </strong>Fourier shell analysis allows for disentangling and quantifying resolution gain and denoising of SR methods in 4D flow MRI and should serve as an additional metric when assessing SR approaches.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1983-1990"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13418888/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148226255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atlas of Brain Glucose Metabolism Using Deuterium Metabolic Imaging at 3 T.","authors":"Kamilla K Trosborg, Nichlas V Christensen, Malene Aastrup, Nikolaj Bøgh, Janne K Mortensen, Hanne Gottrup, Per Borghammer, Mattias H Kristensen, Esben S S Hansen, Sofie H Christensen, Jack J Miller, Rolf F Schulte, Michael Vaeggemose, Lotte B Bertelsen, Christoffer Laustsen","doi":"10.1002/mrm.70451","DOIUrl":"10.1002/mrm.70451","url":null,"abstract":"<p><strong>Purpose: </strong>Deuterium metabolic imaging (DMI) offers noninvasive magnetic resonance imaging (MRI)-based assessment of metabolism in vivo, making it a relevant paraclinical tool for diseases with neurological metabolic alterations. This study aimed to establish a normative reference atlas of brain glucose metabolism accounting for age and sex.</p><p><strong>Methods: </strong>DMI were obtained for 30 healthy adults (aged 51-84 years, 15 female) with a 3 T MRI scanner after ingestion of deuterated [6,6'-²H₂]glucose. The images were parcellated to determine the regional distribution of deuterated water, glucose, lactate, and glutamate plus glutamine (Glx). Linear models were applied to investigate the effects of age, sex, and other exploratory adjustments. As a proof-of-concept example of atlas application, the normative atlas was compared with patients with Alzheimer's disease and healthy subjects from a previous study.</p><p><strong>Results: </strong>Regional differences were significant for all metabolites (p < 10^-15), with the highest values in the occipital lobes, except for lactate, whose regional distribution pattern was less consistent. While lactate production showed no overall age-dependency, global Glx production decreased 13% ± 4% per decade. Lactate production tended to be higher in males than females (p = 0.042), but this was not significant after regional adjustment (p = 0.084). Discriminating between health and Alzheimer's disease required additional adjustments for weight, blood glucose, and timing.</p><p><strong>Conclusions: </strong>While regional and age effects explained a substantial part of the variability in Glx, reliable intersubject comparisons required additional adjustments. The normative atlas presented here provides a reference for future DMI studies of brain metabolism.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1834-1845"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419004/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148101722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying Cardiac, Respiratory, and Low Frequency Components of CSF Motion From fMRI Inflow Effects.","authors":"Pontus Söderström, Cecilia Björnfot, Britt M Andersson, Jan Malm, Anders Eklund, Anders Wåhlin","doi":"10.1002/mrm.70438","DOIUrl":"10.1002/mrm.70438","url":null,"abstract":"<p><strong>Purpose: </strong>Cerebrospinal fluid (CSF) flow oscillations have emerged as a potentially important marker related to brain clearance, but their acquisition often relies on specialized imaging MRI sequences. The purpose of this work was to enable quantitative assessment of CSF flow associated with cardiac, respiratory, and low-frequency cycles using widely available functional magnetic resonance imaging (fMRI) acquisitions.</p><p><strong>Methods: </strong>A method was developed to translate fMRI-derived CSF inflow signals into quantitative flow rates. This approach modeled the spin-history of an oscillating ensemble of molecules. Validation was performed using phantom experiments with cardiac-, respiratory-, and low-frequency-like oscillatory flow. The method was further applied to resting-state data from 48 older adults (68-82 years, 19 women) to characterize CSF flow at the foramen magnum.</p><p><strong>Results: </strong>Phantom experiments demonstrated excellent correlations between estimated and true velocities for cardiac- and respiratory-like frequencies (r = 0.94 and 0.97, respectively) and moderate correlation for the low-frequency-like oscillation (r = 0.58). In the population cohort, median CSF stroke volumes were 0.77 [0.57, 1.09] mL for the cardiac cycle, 0.38 [0.26, 0.88] mL for the respiratory cycle, and 0.26 [0.14, 0.39] mL for the low-frequency cycle.</p><p><strong>Conclusion: </strong>The proposed spin-history modeling method enabled quantitative estimation of CSF flow components using a conventional fMRI dataset and showed that the cardiac cycle dominates CSF motion at the foramen magnum.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1916-1928"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13418971/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147964084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methods for Uncertainty Quantification in Dictionary Matching to Advance Reliability of Quantitative MRI.","authors":"Brian Toner, Ute Goerke, Eze Ahanonu, Kevin Johnson, Vibhas Deshpande, Holden H Wu, Maria I Altbach, Ali Bilgin","doi":"10.1002/mrm.70459","DOIUrl":"10.1002/mrm.70459","url":null,"abstract":"<p><strong>Aims: </strong>Purpose: Dictionary matching is a standard tool in quantitative MRI (qMRI), but typically lacks uncertainty quantification (UQ). This is critical when advanced reconstructions (e.g., compressed sensing, deep learning) introduce complex-valued, spatially varying, and temporally correlated noise that violates standard assumptions of independent and identically distributed (iid) noise.</p><p><strong>Methods: </strong>Two voxel-wise uncertainty methods: a frequentist Likelihood Ratio Test (LRT) and a Bayesian marginal posterior approach, are introduced. Noise is modeled as spatially varying and temporally correlated using the covariance estimated from background regions. Methods were validated via simulations and phantom experiments using radial turbo spin-echo ( <math> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>2</mn></mrow> </msub> </mrow> </math> mapping) and radial Look-Locker ( <math> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>1</mn></mrow> </msub> </mrow> </math> mapping). In vivo experiments characterized uncertainty under varying acceleration factors.</p><p><strong>Results: </strong>Simulations confirmed both methods achieve nominal coverage rates (e.g., 95% intervals containing the true value 95% of the time) where standard iid assumptions fail. Phantom results showed excellent agreement with gold-standard spin-echo references. In vivo experiments highlighted that higher acceleration factors widen uncertainty intervals for <math> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>1</mn></mrow> </msub> </mrow> </math> and <math> <mrow> <msub><mrow><mi>T</mi></mrow> <mrow><mn>2</mn></mrow> </msub> </mrow> </math> . The LRT method proved more computationally efficient than the Bayesian approach while providing comparable interval estimates.</p><p><strong>Conclusion: </strong>A robust framework is presented for UQ in dictionary-matched qMRI. By modeling the non-iid noise inherent in modern reconstructions, these methods provide statistically interpretable UQ that assesses the reliability of parameter maps in clinical settings.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1956-1971"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419121/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148199561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First Clinical-Scale Use of a Percutaneous EPR Oxygen Probe (OxyTrack) for Deep-Tissue pO₂ Measurements in a Canine Cancer Patient.","authors":"Conner S Ubert, Maciej M Kmiec, Sergey V Petryakov, Alireza Kheirollah, Ryan C O'Connell, P Jack Hoopes, Periannan Kuppusamy","doi":"10.1002/mrm.70449","DOIUrl":"10.1002/mrm.70449","url":null,"abstract":"<p><strong>Purpose: </strong>To assess the safety, feasibility, and performance of a percutaneously insertable L-band electron paramagnetic resonance (EPR) oxygen sensor (OxyTrack) for depth-resolved pO₂ measurement in a spontaneous canine osteosarcoma, and to evaluate its translational potential.</p><p><strong>Methods: </strong>A custom 1.15 GHz continuous-wave EPR spectrometer was used together with two needle-type resonators. An 8-cm, 1-mm-OD OxyTrack measured pO₂ at five depths (2-38 mm) by incremental retraction; a 5-cm, 0.5-mm-OD OxyTrack, mounted on a guiding cannula, enabled alternating measurements in tumor versus adjacent muscle at ∼30-s intervals for 6 min. Data were analyzed in RStudio; means ± SEM were taken from the final minute of each depth.</p><p><strong>Results: </strong>The pO₂ values (± SEM) in the osteosarcoma tumor were 49.26 ± 0.71 mmHg (at 2 mm depth), 50.82 ± 0.25 mmHg (at 8 mm), 19.62 ± 0.47 mmHg (at 18 mm), 4.78 ± 0.05 mmHg (at 28 mm), and 18.15 ± 0.30 mmHg (at 38 mm). The 28-mm site exhibited severe hypoxia. Equilibration followed a mono-exponential model (R² > 0.98) with half-times 0.35-1.17 min. Simultaneous muscle versus tumor measurements gave mean pO₂ of 33.9 ± 2.1 mmHg and 8.0 ± 0.7 mmHg, respectively (ratio ∼4.2:1). No adverse events occurred.</p><p><strong>Conclusion: </strong>OxyTrack provides safe, real-time, quantitative pO₂ assessment at depths > 3 cm, revealing marked intra-tumoral oxygen heterogeneity that single-point methods miss. These findings demonstrate feasibility for clinical translation of EPR oximetry to guide radiotherapy and hypoxia-targeted therapies and support further translational development.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"2029-2036"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419029/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148055592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Temporal-Resolution Monitoring of Creatine and Phosphocreatine Dynamics in Skeletal Muscle Using Ultrafast Z-Spectroscopy (UFZ) CEST MRI at 3T.","authors":"Licheng Ju, T Jake Samuel, Michael Schär, Kexin Wang, Yihan Wu, Robert G Weiss, Jiadi Xu","doi":"10.1002/mrm.70464","DOIUrl":"10.1002/mrm.70464","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the feasibility of High-Temporal-Resolution (HTR) Ultrafast Z-spectrum (UFZ) CEST MRI for monitoring the dynamic fluctuations of phosphocreatine (PCr) and creatine (Cr) in human skeletal muscle (SM) at 3 T during and after exercise.</p><p><strong>Methods: </strong>HTR UFZ-CEST MRI of SM was achieved using a 1D spatial and spectral encoding with a 2D turbo spin-echo readout. Five healthy subjects performed in-magnet plantar flexion exercise, and dynamic changes in Amide, PCr, and partial PCr-mixed creatine (Cr⁺) CEST signals were quantified using the Polynomial and Lorentzian Line-shape Fitting (PLOF) method. This approach enables monitoring of PCr/Cr CEST dynamics throughout exercise and recovery.</p><p><strong>Results: </strong>Dynamic CEST contrasts with 7.6 s temporal resolution revealed PCr depletion (-76.9% ± 17.7%) and concomitant Cr elevation (469.0% ± 116.3%) during exercise, followed by exponential PCr recovery and Cr decay during recovery. The post-exercise recovery constants for Cr and PCr CEST were 61.5 ± 45.6 s and 73.3 ± 66.1 s, respectively. Using two-step Bloch-McConnell simulation based on the experimental lineshape and CEST changes, we estimated an exchange rate of 150 ± 70 s^-1 for CrCEST and 185 ± 105 s^-1 for PCrCEST in the resting state.</p><p><strong>Conclusion: </strong>These results establish UFZ-CEST as a rapid, noninvasive method for mapping Cr/PCr dynamics in human SM and provide a foundation for clinical assessment of mitochondrial function.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1798-1805"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148176417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blind Estimation Versus Direct Measurement of the Arterial Input Function in Dynamic Contrast-Enhanced MRI of the Breast.","authors":"Jake L Cray, Jiří Vitouš, Radovan Jiřík, Sofya Titarenko, David L Buckley","doi":"10.1002/mrm.70454","DOIUrl":"10.1002/mrm.70454","url":null,"abstract":"<p><strong>Purpose: </strong>Accurate arterial input functions (AIFs) are essential for quantitative dynamic contrast-enhanced (DCE) MRI, yet direct measurement is challenging and population-averaged AIFs neglect patient-specific variability. Blind deconvolution provides an alternative by estimating patient-specific AIFs directly from tissue data, up to a scale factor. This study compared blindly estimated AIFs with carefully measured aortic AIFs in breast DCE-MRI.</p><p><strong>Theory and methods: </strong>Data from 25 patients with breast cancer were analyzed, each with a carefully measured AIF. Blind AIF estimates were obtained using model-constrained deconvolution in the Perflab toolkit with both Tofts-Kety (TK) and two-compartment exchange (2CXM) tissue models. To help isolate AIF shape blind AIFs were scaled using cardiac output. These blind AIFs were compared with measured AIFs using scale-invariant and scale-dependent metrics which assess the similarity of the AIF shape.</p><p><strong>Results: </strong>Blind estimates were obtained for all 25 patients with both tissue models. Compared with measured AIFs, blind estimates derived using the 2CXM showed stronger agreement across all metrics than those derived using the TK model. However, the weak correlation in scale-dependent metrics suggests limitations of cardiac output scaling.</p><p><strong>Conclusion: </strong>Blind AIF estimation using the 2CXM provides more reliable recovery of AIF shape and dispersion than the TK model in breast DCE-MRI. While blind deconvolution shows promise for estimating local patient-specific AIFs other scaling strategies may need to be employed in practice.</p>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":" ","pages":"1947-1955"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13419040/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148239634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}