Ehman, Richard

Background: Accurate identification of patients with metabolic dysfunction–associated steatohepatitis (MASH) at risk of disease progression (at-risk MASH) is critical for guiding resmetirom and semaglutide therapy. Inconsistent definitions of at-risk MASH complicate clinical risk classification and comparisons across studies. This study aimed to standardize the definition of at-risk MASH and propose optimized MRE-based liver stiffness (LS-MRE) cutoffs to improve noninvasive risk stratification and better guide pharmacotherapy. Methods: In this prospective study, 413 patients with suspected or diagnosed MASLD from two medical centers underwent liver biopsy and MRE. Results: A simplified definition of at-risk MASH (MASH with fibrosis stage≥2) identified a broader group of patients requiring clinical attention than a stricter definition requiring NAFLD Activity Score≥4 with ≥1 point in steatosis, inflammation, and ballooning (n=122 vs. 77). LS-MRE alone showed the highest diagnostic accuracy for identifying at-risk MASH using the simplified definition (AUC 0.91 [0.87, 0.95]) and cirrhosis (AUC 0.93 [0.88, 0.99]), compared with FIB-4 and individual laboratory parameters (AST, ALT, and platelet count) ( p <0.01 for all, paired DeLong tests). Optimized LS-MRE cutoffs (2.8–6.4 kPa) captured 25 additional biopsy-proven pharmacotherapy candidates (28% of all eligible patients) compared to AASLD guidelines–recommended cutoffs (3.1–4.4 kPa), improving sensitivity (80% vs. 50%) with acceptable specificity (73% vs. 88%). Conclusions: A simplified definition of at-risk MASH enables broader identification of treatment candidates. LS-MRE demonstrates excellent diagnostic performance and improves noninvasive risk stratification when paired with optimized cutoffs. These findings support the use of MRE to guide resmetirom and semaglutide eligibility and improve access to emerging therapies.

Compared with two-dimensional MR elastography (MRE), three-dimensional MRE demonstrated better test-retest repeatability, between–field-strength reproducibility, and between-day reproducibility at 3 T for measurement of liver stiffness in adults with severe obesity but failed more frequently.

ABSTRACT Background Metabolic dysfunction‐associated steatotic liver disease (MASLD) exhibits marked heterogeneity in fibrosis progression and liver‐related outcomes. Liver biopsy is not feasible for longitudinal risk stratification at scale, creating a need for validated non‐invasive biomarkers, particularly imaging biomarkers, that can predict clinically meaningful disease progression and liver‐related outcomes. Aims To describe the design and rationale of the GOLDMINE study, established to determine whether non‐invasive imaging biomarkers predict MASLD progression and liver‐related clinical outcomes. Methods GOLDMINE is an investigator‐initiated, multi‐centre, international longitudinal cohort enrolling up to 1000 adults with either biopsy‐proven MASLD or MASLD cirrhosis across the full fibrosis spectrum. Participants are recruited from 15 sites in the US and 4 international sites (Japan, Singapore and France). At baseline, participants undergo clinical phenotyping, vibration‐controlled transient elastography, and advanced magnetic resonance imaging (MRI), including proton‐density‐fat‐fraction and magnetic resonance elastography (MRE). MRI (and biospecimen banking) is repeated at 2‐year intervals (years 2 and 4), with annual follow‐up visits for up to 10 years. Baseline liver histology is centrally processed, digitized and reviewed by a single expert hepatopathologist; all MRI/MREs are centrally interpreted. Results The prespecified clinical outcomes include progression to cirrhosis, clinically significant portal hypertension, major adverse liver‐related outcomes (ascites, hepatic encephalopathy, portal hypertensive bleeding, liver transplantation/qualification), hepatocellular carcinoma, major adverse cardiovascular events, and all‐cause mortality, with independent central adjudication of all events. Conclusions GOLDMINE establishes a rigorously phenotyped MASLD cohort integrating centralized histology, advanced MRI‐based biomarkers, longitudinal biobanking, and adjudicated outcomes, providing a platform to validate imaging and blood‐based prognostic biomarkers in MASLD.

ABSTRACT Purpose Active lesion expansion is clinically important because it can indicate disease progression and influence management and treatment planning. However, sequential imaging is often unavailable, and rapid growth can only be inferred from indirect findings such as active perilesional tissue injury. This study aimed to implement and test the feasibility of an MR elastography (MRE)‐based technique for assessing the expansile nature of mass lesions by detecting stiffness changes caused by mechanical strain manifestations in adjacent tissues. Methods A tissue strain mapping (TSM) algorithm was developed using spatial–temporal directional filtering to reveal the presence of perilesional latent strain that is not apparent in conventional MRE inversions. The technical feasibility was tested in tissue‐simulating phantoms containing a mass that was progressively expanded. Preliminary feasibility for clinical application was also demonstrated in representative in vivo examples. Resulting TSM maps were compared with conventional MRE stiffness maps. Results In the phantom experiments, TSM revealed the presence of local strain at the periphery of the expanding mass, with the effect increasing proportionally to the degree of expansion. Conventional MRE did not demonstrate comparable localized stiffening patterns. In vivo examples showed similar perilesional strain features that were not apparent on conventional MRE maps. Conclusion The feasibility of the proposed MRE‐based TSM technique was demonstrated in phantom and preliminary in vivo studies. These findings suggest that the technique is a promising tool for assessing the expansile nature of mass lesions and motivate further development of the TSM processing and exploration of potential clinical applications.

ABSTRACT Purpose Magnetic resonance elastography (MRE) of the heart has predominantly utilized breath‐held acquisitions with limited anatomic coverage. This work investigates the feasibility of 3D, free‐breathing cardiac MRE. Methods A 3D hybrid radial and EPI acquisition is utilized and combined with retrospective binning of k ‐space via physiologic monitoring, iterative reconstruction, MRE processing and inversions, and post‐processing specialized for cardiac imaging. Results Feasibility of free‐breathing stiffness mapping of the left ventricular myocardium was demonstrated in 11 participants. Myocardial stiffness estimates were obtained throughout the left ventricle for seven temporal states of the cardiac cycle. Stiffness estimates were presented in participant‐specific images, 17‐segment bullseye plots, and stiffness plots throughout the cardiac cycle. Results indicate increased stiffness in systolic states, with localized stiffness heterogeneity observed between participants, illustrating a key benefit of 3D cardiac MRE acquisition. Mean stiffness estimates obtained through 11 subjects were 4.44 ± 0.68 kPa (begin‐systole), 5.74 ± 0.94, 5.42 ± 0.87 (end‐systole), 3.84 ± 0.71 (begin‐diastole), 3.51 ± 0.74, 3.54 ± 0.52, and 3.55 ± 0.59 kPa (end‐diastole). Statistical testing indicated significant differences in stiffness across cardiac states with one‐way, repeated‐measures ANOVA ( p < 0.001) and Friedman's test ( p < 0.001). Experiments in scanning three participants with and without applied motion indicated that stiffness changes were more robustly detected in systole than in diastole, although patterns were subject‐specific. Comparison of free‐breathing stiffness measurements against reference breath‐held measurements yielded similar systolic stiffness estimates. Conclusions This study establishes the feasibility of free‐breathing, 3D cardiac MRE in healthy volunteers. With the current framework, stiffness estimation appears more robust in systole, and the reliability of diastolic estimates is limited and subject‐specific.

ABSTRACT Purpose Abnormal restrictions at myofascial interfaces are a key factor in chronic low back pain (CLBP) with myofascial pain syndrome (MPS), but no established imaging method exists for quantitative assessment. This pilot study evaluated the clinical feasibility of MR elastography (MRE)‐based slip interface imaging (SII) for visualizing myofascial mobility in CLBP‐MPS patients versus age−/sex‐/BMI‐matched healthy participants. A new SII biomarker, maximal normalized displacement discontinuity (), was introduced, and the previously developed normalized octahedral shear strain (NOSS) map was used for comparison. Preliminary assessments of vibration‐frequency effects, repeatability, and group differences in inter‐muscular mobility were conducted. Methods MRE was conducted at 30, 60, and 90 Hz to compare with NOSS for visualizing inter‐muscular slip interfaces at the quadratus lumborum‐erector spinae (QL‐ES) and erector spinae‐multifidus (ES‐M) muscle boundaries at L3‐L4. Repeatability of and NOSS was assessed at 30 Hz (identified as the best‐performing frequency) using within‐subject coefficients of variation and a linear mixed‐effects model from within‐ and between‐day scans. Clinical feasibility was then assessed via Wilcoxon rank‐sum tests in six CLBP‐MPS patients and matched controls. Results at 30 Hz exhibited superior delineation of slip interfaces compared to higher frequencies and NOSS. demonstrated significantly lower variation and better repeatability than NOSS. Healthy participants showed continuous, well‐defined slip interfaces, whereas CLBP‐MPS patients displayed disrupted interfaces with significant mobility reduction at L4 ES‐M. Conclusion SII with lower vibration frequency and map enhances visualization of lower back myofascial mobility and shows potential for assessing differences between healthy individuals and CLBP‐MPS patients.

ABSTRACT Background Magnetic resonance elastography (MRE) has demonstrated potential in characterizing intracranial tumors, including glioblastoma. The influence of pathology on measurement consistency and interobserver agreement needs evaluation to promote MRE implementation as a quantitative biomarker. Purpose To assess repeatability and interobserver agreement of absolute and normalized magnitude of the complex shear modulus (| G *|), storage modulus ( G ′), and loss modulus ( G ″) in glioblastoma. Study Type Prospective. Population Thirteen adults (5 male, 8 female, mean age 66.23 years) with histopathologically confirmed glioblastoma. Field Strength/Sequence 3 T MRI, modified single‐shot spin‐echo echo‐planar imaging. Assessment Two same‐session MRE acquisitions were performed with patient repositioning. The solid tumor component was independently segmented by 2 observers on contrast‐enhanced T1‐weighted images co‐registered to MRE maps. Statistical Tests Repeatability was assessed using the repeatability coefficient, coefficient of variation, and Bland–Altman plots, and interobserver agreement by the intraclass correlation coefficient. The Wilcoxon signed‐rank test compared parameters and coefficients of variation between tumor‐normal‐appearing white matter and absolute and normalized measurements. Significance was set at 0.05. Results Tumor | G *| and G ′ showed repeatability coefficients of 0.07–0.08 kPa and 0.05 kPa, compared with 0.13 kPa (| G *|) and 0.15–0.16 kPa ( G ′) for normalized measurements. Coefficients of variation in tumor regions were 1.42% ± 1.12%–1.60% ± 1.41% for | G *| and 1.19% ± 0.96%–2.08% ± 2.22% for G ′, significantly lower than normalized values (4.82% ± 4.49%–4.21% ± 4.27% for | G *|; 5.12% ± 5.04%–5.45% ± 4.53% for G ′). Tumor | G *| and G ′ showed excellent interobserver agreement (intraclass correlation coefficients 0.97 and 0.95). Tumor G ″ demonstrated higher variability than | G *| and G ′ (coefficients of variation 8.58% ± 7.69%–7.51% ± 6.73%), with no significant difference between absolute and normalized measurements ( p = 0.14). Data Conclusion Tumor | G *| and G ′ are the most repeatable metrics in glioblastoma. Normalization reduces measurement repeatability due to normal‐appearing white matter variability. The small sample size ( n = 13) limits generalizability. Evidence Level 2. Technical Efficacy Stage 2.

Background: It is crucial to evaluate liver fibrosis in metabolic dysfunction-associated steatotic liver disease (MASLD). Digital pathology, an automated method for quantitative fibrosis measurement, provides valuable support to pathologists by providing refined continuous metrics and addressing inter-observer variability. Although non-invasive tests (NITs) have been validated as consistent with manual pathology, the relationship between digital pathology and NITs remains unexplored. Methods: This study included 99 biopsy-proven MASLD patients. Quantitative-fibrosis (Q-Fibrosis) used second-harmonic generation/two-photon excitation fluorescence microscopy (SHG/TPEF) to quantify fibrosis parameters (q-FPs). Correlations between eight NITs and q-FPs were analyzed. Results: Using manual pathology as standard, Q-Fibrosis exhibited excellent diagnostic performance in fibrosis stages assessment with area under the receiver operating characteristic curves (AUCs) ranging from 0.924 to 0.967. In addition, magnetic resonance elastography (MRE) achieved the highest diagnostic accuracy (AUC: 0.781–0.977) among the eight NITs. Furthermore, MRE-assessed liver stiffness measurement (MRE-LSM) showed the strongest correlation with q-FPs, particularly adjusted by string length, string width, and the number of short and thick strings within the portal region. Conclusions: Both MRE and digital pathology demonstrated excellent diagnostic accuracy. MRE-LSM was primarily determined by collagen extent, location and pattern, which provide a new perspective for understanding the relationship between the change in MRE and histological fibrosis reverse.

ABSTRACT Background and Aims Clinically significant portal hypertension (CSPH; hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) is a severe complication of chronic liver disease, with increased risk of variceal bleeding and liver decompensation (at HVPG ≥ 12 mmHg). This study evaluated the performance of multiparametric (mp)MRI for diagnosing CSPH and predicting liver decompensation, compared to ultrasound‐based shear wave elastography (SWE) and blood tests. Methods In this prospective single‐centre study (2018–2022), 59 patients (M 30, mean age 52.7 years) underwent mpMRI and HVPG measurement, with an average interval of 32 ± 31 days. The mpMRI protocol included 2D/3D MR elastography (MRE), T 1 /proprietary iron‐compensated T 1 (cT 1 )/T 1ρ mapping, gadoxetate‐enhanced dynamic contrast‐enhanced MRI (DCE‐MRI) of the liver and spleen, SWE and blood tests. Statistical analyses included Mann–Whitney U tests, ROC analysis, logistic regression and Cox proportional hazards models. Results CSPH was present in 13 patients (22%). Several MRI parameters showed high diagnostic performance for CSPH (AUC ≥ 0.8), with spleen stiffness‐2D MRE (AUC 0.88, 95% confidence interval (CI) 0.78–0.98) and liver uptake on DCE‐MRI (AUC 0.83, 95% CI 0.70–0.96) performing best, while SWE had AUCs of 0.63 (95% CI 0.45–0.81) for liver and 0.67 (95% CI 0.44–0.89) for spleen. Combining spleen stiffness‐2D MRE and liver uptake achieved an AUC of 0.93 (95% CI 0.86–1.00) for diagnosing CSPH. For predicting decompensation, spleen stiffness‐3D MRE and liver uptake rate had AUCs of 0.83 (95% CI 0.68–0.99) and 0.83 (95% CI 0.70–0.95), respectively, outperforming SWE. Conclusions Spleen stiffness measured with MRE combined with gadoxetate liver uptake (measured with DCE‐MRI) can diagnose CSPH and predict liver decompensation, with superior performance compared to SWE. Trial Registration ClinicalTrials.gov identifier: NCT03436550

ABSTRACTBackgroundPercutaneous transluminal angioplasty and stenting (PTAS) in patients with carotid stenosis may have potential effects on brain parenchyma. However, current studies on parenchymal changes are scarce due to the need for advanced imaging modalities. Consequently, the alterations in brain parenchyma following PTAS remain an unsolved issue.PurposeTo investigate changes to the brain parenchyma using magnetic resonance elastography (MRE).Study TypeProspective.Population13 patients (6 women and 7 men; 39 MRI imaging sessions) with severe unilateral carotid stenosis patients indicated for PTAS were recruited between 2021 and 2024.Field Strength/SequenceNoncontrast MRI sequences including MRE (spin echo) were acquired using 3 T scanners.AssessmentAll patients underwent MRE before (preprocedural), within 24 h (early postprocedural) and 3 months after (delayed postprocedural) PTAS. Preprocedural and delayed postprocedural ultrasonographic peak systolic velocity (PSV) was recorded. MRE stiffness and damping ratio were evaluated via neural network inversion of the whole brain, in 14 gray matter (GM) and 12 white matter (WM) regions.Statistical TestsStiffness and damping ratio differences between each pair of MR sessions for each subject were identified by paired sample t tests. The correlations of stiffness and damping ratio with stenosis grade and ultrasonographic PSV dynamics were evaluated by Pearson correlation coefficients. The statistical significance was defined as p < 0.05.ResultsThe stiffness of lesion side insula, deep GM, and deep WM increased significantly from preprocedural to delayed postprocedural MRE. Increasing deep GM stiffness on the lesion side was positively correlated with the DSA stenosis grade significantly (r = 0.609). The lesion side insula stiffness increments were positively correlated with PSV decrements significantly (r = 0.664).Data ConclusionRegional brain stiffness increased 3 months after PTAS. Lesion side stiffness was positively correlated with stenosis grades in deep GM and PSV decrements in the insula.Evidence Level2.Technical EfficacyStage 2.