LAUSR

To assess liver necroinflammation in HCV patients undergone antiviral therapy by Gd-EOB-DTPA-enhanced MRI with histopathologic analyses as reference. HCV patients were enrolled in this prospective study before antiviral treatment between 09–2016 and 07–2017. Unenhanced MR, Gd-EOB-DTPA-enhanced MR, and liver biopsy were performed before and 24 weeks after treatment of daclatasvir with asunaprevir (DAA). DWI was obtained using a breath-hold single-shot echo planar spin-echo sequence. Twenty minutes after administration of Gd-EOB-DTPA, the relative enhancement (RE) and the contrast enhancement index (CEI) were recorded. Liver necroinflammatory activity grades (G0–18) were categorized on the Ishak Scoring systems. CEI, RE, and DWI of baseline and 24 weeks after treatment were compared by paired t test. Relationship between MR parameters and histologic scores was evaluated by Pearson’s correlation. Receiver operating characteristic analysis evaluated the measurements’ diagnostic performance. MRI variability between two readers was assessed using the intraclass correlation coefficient.Results A decrease of liver necroinflammatory activity grade (p < 0.0001) was detected in final cohort (n = 21; mean age 44 years; 23 to 67 years; 11 F, 10 M). Statistical results of 42 person-times in 21 patients at baseline and follow-up showed CEI and ADC were significantly different (p = 0.006 and 0.036) across histologic grades of liver necroinflammation. Significant increase of CEI, RE, and ADC (p = 0.0004, 0.0032, 0.0110) 24 weeks after DAA treatment was seen. Additionally, CEI was correlated to necroinflammatory grade (r =  − 0.596, p = 0.006). AUROC for CEI, ADC, and CEI combined with ADC to differentiate patients with none and mild (G0–6) from patients with moderate and severe necroinflammation (G7–18) was 0.834 (95% CI 0.712–0.956, 0.724(95% CI 0.565–0.884) and 0.837(95% CI 0.717–0.956). Gd-EOB-DTPA-enhanced MRI by CEI could be used as a noninvasive imaging biomarker to distinguish grades of necroinflammatory activity in patients with HCV after DAAs therapy at early stage and CEI combined with ADC could get a better diagnostic accuracy.