Non-invasive evaluation of liver fibrosis: a comparison of ultrasound-based transient elastography and MR elastography in patients with viral hepatitis B and C.

ABSTRACT

OBJECTIVE: To compare the diagnostic accuracy of TE and MRE and establish cutoff levels and diagnostic strategies for both techniques, enabling selection of patients for liver biopsy. METHODS: One hundred three patients with chronic hepatitis B or C and liver biopsy were prospectively included. Areas under curves (AUROC) were compared for TE and MRE for METAVIR fibrosis grade ≥ F2 and ≥F3. We defined cutoff values for selection of patients with F0-F1 (sensitivity >95%) and for significant fibrosis F2-F4 (specificity >95%). RESULTS: Following exclusions, 85 patients were analysed (65 CHB, 19 CHC, 1 co-infected). Fibrosis stages were F0 (n = 3), F1 (n = 53), F2 (n = 15), F3 (n = 8) and F4 (n = 6). TE and MRE accuracy were comparable [AUROCTE ≥ F2 0.914 (95% CI 0.857-0.972) vs. AUROCMRE ≥ F2 0.909 (0.840-0.977), P = 0.89; AUROCTE ≥ F3 0.895 (0.816-0.974) vs. AUROCMRE ≥ F3 0.928 (0.874-0.982), P = 0.42]. Cutoff values of <5.2 and ≥8.9 kPa (TE) and <1.66 and ≥2.18 kPa (MRE) diagnosed 64% and 66% of patients correctly as F0-F1 or F2-F4. A conditional strategy in inconclusive test results increased diagnostic yield to 80%. CONCLUSION: TE and MRE have comparable accuracy for detecting significant fibrosis, which was reliably detected or excluded in two-thirds of patients. A conditional strategy further increased diagnostic yield to 80%. KEY POINTS • Both ultrasound-based transient elastography and magnetic resonance elastography can assess hepatic fibrosis. • Both have comparable accuracy for detecting liver fibrosis in viral hepatitis. • The individual techniques reliably detect or exclude significant liver fibrosis in 66 %. • A conditional strategy for inconclusive findings increases the number of correct diagnoses.