Correlation of the Speed of Enhancement of Hepatic Hemangiomas with Intravoxel Incoherent Motion MR Imaging

Abstract

Purpose : To evaluate the relationship between the speed of enhancement of hepatic hemangiomas on gadoliniumenhanced MRI and ADC values by using various parameters, including the D, f, D* and ADC fit on intravoxel incoherent motion (IVIM) MR Imaging. Materials and Methods:The institutional review board approved this retrospective study. A total of 47 hepatic hemangiomas from 39 patients were included (20 men and 19 women). The hemangiomas were classified into three types according to the enhancement speed of the hepatic hemangiomas on gadolinium-enhanced dynamic T1-weighted images: rapid (Type A), intermediate (Type B), and slow (Type C) enhancement. The D, f, D* and ADC fit values were calculated using IVIM MR imaging. The diffusion/perfusion parameters and ADC values were compared among the three types of hemangiomas.Results: Both the ADC fit and D values of type C were significantly lower than those of type A (P = 0.0022, P = 0.0085). However, for the f and D*, there were no significant differences among the three types. On DWI with all b values (50, 200, 500 and 800 sec/mm 2 ), the ADC values of type C were significantly lower than those of the type A (P < 0.012). For b values with 800 sec/mm 2 , the ADC 800 values of the type C hemangiomas were significantly lower than those of type B (P = 0.0021). We found a negative correlation between hepatic hemangioma enhancement type and ADC 50 (ρ= -0.357, P = 0.014), ADC 200 (ρ= -0.537, P = 0.0001), ADC 500 (ρ= -0.614, P = 0.0001), and ADC 800 (ρ= -0.607, P = 0.0001). Therefore, four ADC values of ADC 50 , ADC 200 , ADC 500 , and ADC 800 were decreased with decreasing enhancement speed.Conclusion: Hepatic hemangiomas had variable ADCs according to the type of enhancement, and the reduced ADCs in slowly enhancing hemangiomas may be related to the reduced pure molecular diffusion (D).