Bane, Octavia

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

Renal diseases pose a significant socio‐economic burden on healthcare systems. The development of better diagnostics and prognostics is well‐recognized as a key strategy to resolve these challenges. Central to these developments are MRI biomarkers, due to their potential for monitoring of early pathophysiological changes, renal disease progression or treatment effects. The surge in renal MRI involves major cross‐domain initiatives, large clinical studies, and educational programs. In parallel with these translational efforts, the need for greater (patho)physiological specificity remains, to enable engagement with clinical nephrologists and increase the associated health impact. The ISMRM 2022 Member Initiated Symposium (MIS) on renal MRI spotlighted this issue with the goal of inspiring more solutions from the ISMRM community. This work is a summary of the MIS presentations devoted to: 1) educating imaging scientists and clinicians on renal (patho)physiology and demands from clinical nephrologists, 2) elucidating the connection of MRI parameters with renal physiology, 3) presenting the current state of leading MR surrogates in assessing renal structure and functions as well as their next generation of innovation, and 4) describing the potential of these imaging markers for providing clinically meaningful renal characterization to guide or supplement clinical decision making. We hope to continue momentum of recent years and introduce new entrants to the development process, connecting (patho)physiology with (bio)physics, and conceiving new clinical applications. We envision this process to benefit from cross‐disciplinary collaboration and analogous efforts in other body organs, but also to maximally leverage the unique opportunities of renal physiology.Level of Evidence1Technical Efficacy Stage2

Objective The aim of this study was to compare 2-dimensional (2D) gradient recalled echo (GRE) and 2D spin echo echoplanar imaging (SE-EPI) magnetic resonance elastography (MRE) sequences of the liver in terms of image quality and quantitative liver stiffness (LS) measurement. Materials and Methods This prospective study involved 50 consecutive subjects (male/female, 33/17; mean age, 58 years) who underwent liver magnetic resonance imaging at 3.0 T including 2 MRE sequences, 2D GRE, and 2D SE-EPI (acquisition time 56 vs 16 seconds, respectively). Image quality scores were assessed by 2 independent observers based on wave propagation and organ coverage on the confidence map (range, 0–15). A third observer measured LS on stiffness maps (in kilopascal). Mean LS values, regions of interest size (based on confidence map), and image quality scores between SE-EPI and GRE-MRE were compared using paired nonparametric Wilcoxon test. Reproducibility of LS values between the 2 sequences was assessed using intraclass coefficient correlation, coefficient of variation, and Bland-Altman limits of agreement. T2* effect on image quality was assessed using partial Spearman correlation. Results There were 4 cases of failure with GRE-MRE and none with SE-EPI-MRE. Image quality scores and region of interest size were significantly higher using SE-EPI-MRE versus GRE-MRE (P < 0.0001 for both measurements and observers). Liver stiffness measurements were not significantly different between the 2 sequences (3.75 ± 1.87 kPa vs 3.55 ± 1.51 kPa, P = 0.062), were significantly correlated (intraclass coefficient correlation, 0.909), and had excellent reproducibility (coefficient of variation, 10.2%; bias, 0.023; Bland-Altman limits of agreement, −1.19; 1.66 kPa). Image quality scores using GRE-MRE were significantly correlated with T2* while there was no correlation for SE-EPI-MRE. Conclusions Our data suggest that SE-EPI-MRE may be a better alternative to GRE-MRE. The diagnostic performance of SE-EPI-MRE for detection of liver fibrosis needs to be assessed in a future study.

PurposeTo assess interplatform reproducibility of liver stiffness (LS) and spleen stiffness (SS) measured with magnetic resonance elastography (MRE) based on a 2D gradient echo (GRE) sequence.Materials and MethodsThis prospective Health Insurance Portability and Accountability Act (HIPAA)‐compliant and Institutional Review Board (IRB)‐approved study involved 12 subjects (five healthy volunteers and seven patients with liver disease). A multislice 2D‐GRE‐based MRE sequence was performed using two systems from different vendors (3.0T GE and 1.5T Siemens) on the same day. Two independent observers measured LS and SS on confidence maps. Bland–Altman analysis (with coefficient of reproducibility, CR), coefficient of variability (CV), and intraclass correlation (ICC) were used to analyze interplatform, intra‐ and interobserver variability. Human data were validated using a gelatin‐based phantom.ResultsThere was excellent reproducibility of phantom stiffness measurement (CV 4.4%). Mean LS values were 3.44–3.48 kPa and 3.62–3.63 kPa, and mean SS values were 7.54–7.91 kPa and 8.40–8.85 kPa at 3.0T and 1.5T for observers 1 and 2, respectively. The mean CVs between platforms were 9.2%–11.5% and 13.1%–14.4% for LS and SS, respectively, for observers 1 and 2. There was excellent interplatform reproducibility (ICC >0.88 and CR <36.2%) for both LS and SS, and excellent intra‐ and interobserver reproducibility (intraobserver: ICC >0.99, CV <2.1%, CR <6.6%; interobserver: ICC >0.97, CV and CR <16%).ConclusionThis study demonstrates that 2D‐GRE MRE provides platform‐ and observer‐independent LS and SS measurements. J. Magn. Reson. Imaging 2016;43:1064–1072.