Quantitative CT assessment by histogram and volume ratio in pyrrolizidines alkaloids-induced hepatic sinusoidal obstruction syndrome

•Histogram was firstly used for imaging analysis in patients with PAs-induced HSOS.•The mean Hounsfield unit of damaged area was significantly lower than the corresponding normal liver.•Changes in damaged area-to-normal liver density ratio (ΔDR) derived from histogram was positively correlated with liver function tests.•Heterogeneous hypoattenuation scored by hypoattenuation volume ratio and ΔDR was positively correlated with liver function and MELD score.