The Utility of Elastography in Discriminating Stages of Liver Fibrosis and Risk Stratification in Patients With Primary Sclerosing Cholangitis: A Systematic Review

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic autoimmune disease involving inflammation in the liver and biliary system, manifesting as biliary strictures and cholestasis, and leading to hepatic fibrosis. Due to variable patterns of fibrosis, precise criteria for risk stratification of these patients have yet to be determined. Elasticity-based methods are widely used to estimate the stage of liver fibrosis in PSC. PURPOSE: To review the role of different modalities of quantitative elastography in relation to the clinical and fibrosis biomarkers of PSC for the diagnosis and prognosis of this disease. STUDY TYPE: SYSTEMATIC REVIEW: Population or subjects or phantom or specimen or animal model: We conducted a systematic review, adhering to the PRISMA guidelines, and searched PubMed and found 24 articles on the performance of elastography techniques in PSC. ASSESSMENT: We qualitatively evaluated methodological limitations including patient selection, reference standard, elasticity acquisition protocols, and outcome definitions. STATISTICAL TESTS: N/A. RESULTS: Based on our review, magnetic resonance elastography (MRE) performs better than vibration controlled transient elastography (VCTE), point shear-wave elastography (p-SWE), and acoustic radiation force impulse (ARFI) in prediction of poor clinical outcomes in patients with PSC. MRE, an operator-independent technique, estimates liver stiffness by averaging nearly the total liver volume. Compared with ultrasound-based elastography, MRE has a lower technical failure rate in assessment of liver fibrosis. Liver stiffness determined by MRE is also correlated with clinical scores such as Primary Sclerosing Cholangitis Risk Estimate Tool (PREsTo) and Mayo Risk Score (MRS) in patients with PSC. DATA CONCLUSION: Of the elastography methods reviewed, MRE appears to be a preferred modality for staging liver fibrosis and risk stratification of patients with PSC, whereas ultrasound-based techniques like VCTE are more accessible but might be less accurate. Further studies are warranted to assess the diagnostic and prognostic performance of the various elastography techniques in patients with PSC. TECHNICAL EFFICACY STAGE: 5.