Venkatesh, Sudhakar K

Goals: We aimed to describe the diagnostic and prognostic performance of transient elastography (TE) and magnetic resonance elastography (MRE) in patients with primary biliary cholangitis (PBC). Background: The diagnostic performance of TE and MRE in detecting advanced fibrosis in PBC and in predicting outcomes independent of existing serologic prognostic markers is incompletely understood. Materials and Methods: Five hundred thirty-eight consecutive patients with PBC at 3 centers with liver stiffness (LS) measurements by TE (n=286) or MRE (n=332) were reviewed. LS cutoffs for predicting fibrosis stages were determined by receiver operating characteristic curves among those with a liver biopsy (TE, n=63; MRE, n=98). Cox proportional hazard regression modeling was used to identify associations between covariates and hepatic decompensation. Results: The optimal LS thresholds for predicting histologic stage F4 were 14.40 kPa (area under the curve=0.94) for TE and 4.60 kPa (area under the curve=0.82) for MRE. Both TE and MRE outperformed biochemical markers for the prediction of histologic advanced fibrosis. Optimal LS thresholds to predict hepatic decompensation were 10.20 kPa on TE and 4.30 kPa on MRE. LS by TE and MRE (respectively) remained predictors of hepatic decompensation after adjusting for ursodeoxycholic acid responsiveness [hazard ratio (HR), 1.14; 95% confidence interval (CI), 1.05-1.24 and HR, 1.68; 95% CI, 1.28-2.19] and the GLOBE score (HR, 1.13; 95% CI, 1.07-1.19 and HR, 2.09; 95% CI, 1.57-2.78). Conclusion: LS measurement with either TE or MRE can accurately detect advanced fibrosis and offers additional prognostic value beyond existing serologic predictive tools.

Background and Aims Early detection of perihilar cholangiocarcinoma (CCA) among patients with primary sclerosing cholangitis (PSC) is important to identify more people eligible for curative therapy. While many recommend CCA screening, there are divergent opinions and limited data regarding the use of ultrasound or magnetic resonance imaging (MRI) for early CCA detection, and it is unknown whether there is benefit in testing asymptomatic individuals. Our aims were to assess the diagnostic performances and prognostic implications of ultrasound and MRI‐based CCA detection. Approach and Results This is a multicenter review of 266 adults with PSC (CCA, n = 120) who underwent both an ultrasound and MRI within 3 months. Images were re‐examined by radiologists who were blinded to the clinical information. Respectively, MRI had a higher area under the curve compared with ultrasound for CCA detection: 0.87 versus 0.70 for the entire cohort; 0.81 versus 0.59 for asymptomatic individuals; and 0.88 versus 0.71 for those listed for CCA transplant protocol. The absence of symptoms at CCA diagnosis was associated with improved 5‐year outcomes including overall survival (82% vs. 46%, log‐rank P < 0.01) and recurrence‐free survival following liver transplant (89% vs. 65%, log‐rank P = 0.04). Among those with asymptomatic CCA, MRI detection (compared with ultrasound) was associated with reduction in both mortality (hazard ratio, 0.10; 95% confidence interval, 0.01‐0.96) and CCA progression after transplant listing (hazard ratio, 0.10; 95% confidence interval, 0.01‐0.90). These benefits continued among patients who had annual monitoring and PSC for more than 1 year before CCA was diagnosed. Conclusions MRI is superior to ultrasound for the detection of early‐stage CCA in patients with PSC. Identification of CCA before the onset of symptoms with MRI is associated with improved outcomes.

Disease monitoring in nonalcoholic steatohepatitis (NASH) is limited by absence of noninvasive biomarkers of disease regression or progression. We aimed to examine the role of multiparametric three‐dimensional magnetic resonance elastography (3D‐MRE) and magnetic resonance imaging proton density fat fraction (MRI‐PDFF) in the detection of NASH regression after interventions. This is a single‐center prospective clinical trial of 40 patients who underwent bariatric surgery. Imaging and liver biopsies were obtained at baseline and 1 year after surgery. The imaging protocol consisted of multifrequency 3D‐MRE to determine the shear stiffness at 60 Hz and damping ratio at 40 Hz, and MRI‐PDFF to measure the fat fraction. A logistic regression model including these three parameters was previously found to correlate with NASH. We assessed the model performance in the detection of NASH resolution after surgery by comparing the image‐predicted change in NAFLD activity score (delta NAS) to the histologic changes. A total of 38 patients (median age 43, 87% female, 30 of 38 with NAS ≥ 1, and 13 of 38 with NASH) had complete data at 1 year. The NAS decreased in all subjects with NAS ≥ 1 at index biopsy, and NASH resolved in all 13. There was a strong correlation between the predicted delta NAS by imaging and the delta NAS by histology (r = 0.73, P < 0.001). The strength of correlation between histology and the predicted delta NAS using single conventional parameters, such as the fat fraction by MRI‐PDFF or shear stiffness at 60 Hz by MRE, was r = 0.69 (P < 0.001) and r = 0.43 (P = 0.009), respectively. Conclusion: Multiparametric 3D‐MRE and MRI‐PDFF can detect histologic changes of NASH resolution after bariatric surgery. Studies in a nonbariatric setting are needed to confirm the performance as a composite noninvasive biomarker for longitudinal NASH monitoring.

In this paper, we present our preliminary findings regarding magnetic resonance elastography (MRE) on the livers of 10 patients with systemic amyloidosis. Mean liver stiffness measurements (LSM) and spleen stiffness measurements (SSM) were obtained. Magnetic resonance imaging (MRI) images were analyzed for the distribution pattern of amyloid deposition. Pearson correlation analysis was performed in order to study the correlation between LSM, SSM, liver span, liver volume, spleen span, spleen volume, serum alkaline phosphatase (ALP), N-terminal pro b-type natriuretic peptide (NT pro BNP), and the kappa and lambda free light chains. An increase in mean LSM was seen in all patients. Pearson correlation analysis showed a statistically significant correlation between LSM and liver volume (r = 0.78, p = 0.007) and kappa chain level (r = 0.65, p = 0.04). Interestingly, LSM did not correlate significantly with SSM (r = 0.45, p = 0.18), liver span (r = 0.57, p = 0.08), or serum ALP (r = 0.60, p = 0.07). However, LSM correlated significantly with serum ALP when corrected for liver volume (partial correlation, r = 0.71, p = 0.03) and NT pro BNP levels (partial correlation, r = 0.68, p = 0.04). MRI review revealed that amyloid deposition in the liver can be diffuse, lobar, or focal. MRE is useful for the evaluation of hepatic amyloidosis and shows increased stiffness in hepatic amyloidosis. MRE has the potential to be a non-invasive quantitative imaging marker for hepatic amyloidosis.

AbstractPrimary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by biliary inflammation and fibrosis leading to bile duct strictures, cirrhosis, and carries an increased risk of hepatobiliary malignancies. Magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) is the imaging modality of choice in PSC. As an evolving technology, MRI has other potential applications in the care and study of those patients with PSC. In this review, the authors aim to provide a technical overview on MRI/MRCP and related technologies, summarize its contemporary use in PSC, and discuss its evolving role to predict outcomes and look ahead toward emerging MRI technologies relevant to PSC.