[Magnetic resonance imaging and diffusion weighted imaging features of focal peliosis hepatis].

Objective: To investigate the MRI and diffusion weighted imaging (DWI) features of focal peliosis hepatis. Methods: The clinical data and MRI of 19 cases with focal peliosis hepatis confirmed by pathology from January 2012 to March 2018 in Zhongshan Hospital of Fudan University were retrospectively analyzed. The number, location, size, shape, signal intensity of plain scan of lesions, enhancement pattern of lesions, vessels within lesions, and perfusion disorders of hepatic parenchyma were analyzed. The apparent diffusion coefficient (ADC) values of the lesions and adjacent hepatic parenchyma were measured, then the differences between them were explored statistically. All 24 lesions were categorized into group A with tumor-related chemotherapy and group B without tumor-related chemotherapy. The differences of MR features between the two groups were explored statistically. Results: In all 24 lesions, 22 lesions were located in the right lobe, 2 lesions in the left lobe. The median size was 7.5-72.0 (24.4±17.2) mm.On T(1)WI,21 lesions showed slightly hypointensity, 1 lesion showed slightly hyperintensity and 2 lesions were isointensity; all 24 lesions showed slightly hyperintensity on T(2)WI, and isointensity or slightly hyperintensity on DWI. The mean ADC value was (1.511±0.415)×10(-3) mm(2)/s in the lesions and (1.769±0.690)×10(-3) mm(2)/s in the adjacent hepatic parenchyma, which showed no difference between the two groups ( P> 0.05). On dynamic MR images, 20 lesions showed gradually filling enhancement, 4 lesions showed markedly and persistent enhancement. Punctiform or filiform vessels were found in 9 lesions. Adjacent hepatic perfusion disorders showed in 8 lesions. The median lesion size was 7.5-38.5(17.6±9.8) mm in the tumor-related-chemotherapy group and 9.0-72.0(33.8±21.2) mm in the no chemotherapy group.There was significant difference between the two groups ( P< 0.05). Conclusions: The MRI performance of focal peliosis hepatis had a certain characteristic. MRI combined with diffusion weighted imaging could help to make diagnoses.