Abstract: Objective The aim of this study was to summarize the feature of MRI dynamic enhancement and diffusion weighted imaging in patients with small hepatic hemangioma (sHH). Methods A total of 113 patients with ≤2 cm sHH were enrolled in the hospital between January 2022 and March 2023, and all underwent MRI dynamic enhancement and diffusion weighted imaging (DWI) scans. The feature of MRI dynamic enhancement and DWI were summarized. The apparent diffusion coefficient (ADC), maximum slop of increase (MSI), positive enhancement integral (PEI) and mean time to enhancement (MET) were recorded. Results Out of the 113 patients with sHH, 158 lesions were found by MRI scan, and the proportion of single lesions accounted for 78.8%; the lesion size were (1.7±0.4) cm; according to the distribution of curve types by dynamic contrast enhancement, there were 27 lesions of type I, 29 lesions of type II and 102 lesions of type III; there were 71 lesions in the left lobe and 87 lesions in the right lobe; on dynamic contrast-enhanced MRI, sHH were not significantly enhanced at arterial phase and portal venous phase; compared with liver parenchyma, the lesions generally showed continuous relatively low signal, and slight high signal in delayed phase, presenting with mainly mild to moderate delayed enhancement; the MRI dynamic enhancement scan showed that the MSI, PEI and MET in patients with sHH were(321.0±33.6), (256.6±30.7) and (535.9±61.3)s; the DWI scan showed that ADC in patients with sHH was (2.4±0.4) ×10^-3mm²/s. Conclusion The dynamic contrast-enhanced MRI and DWI scan could provide an important tool for clinical diagnosis of patients with sHH.

Key words: Hepatic hemangioma, MRI dynamic enhancement scan, Diffusion weighted imaging, Feature, Diagnosis