Characterizing focal hepatic lesions by free-breathing intravoxel incoherent motion MRI at 3.0 T

Abstract

Background Diffusion-weighted (DW) imaging is commonly used to distinguish between benign and malignant liver lesions. Purpose To prospectively evaluate the true molecular-diffusion coefficient ( D), perfusion-related diffusion coefficient ( D*), perfusion fraction ( f), and ADC of focal hepatic lesions using a free-breathing intravoxel incoherent motion (IVIM) DW sequence, and to determine if these parameters are useful for characterizing focal hepatic lesions. Material and Methods One hundred and twenty hepatic lesions (34 metastases, 32 hepatocellular carcinoma [HCC], 33 hemangiomas, and 21 liver cysts) in 74 patients were examined. Mean D, D*, f, and ADC values of hepatic lesions were compared among pathologies. ROC curve analyses were performed to assess the performances of D, D*, f, and ADC values for the characterization of liver lesions as benign or malignant. Results The mean D and ADC values of benign lesions were greater than those of malignant lesions ( P < 0.001). Although the mean D and ADC values of liver cysts were greater than those of hemangiomas ( P < 0.001), and these values were not significantly different between metastases and HCCs ( P = 0.99). Area under the ROC curve for ADC values (0.98) was significantly greater ( P = 0.048) than that for D values (0.96) for the differentiation of benign and malignant lesions. Sensitivity and specificity for the detection of malignant lesion were 89% and 98%, respectively, when an ADC cut-off value of 1.40 was applied. Conclusion D and ADC values have more potential for characterizing focal hepatic lesions than D* or f values, and for the differentiation of malignancy and benignity.