The Use of the Apparent Diffusion Coefficient (ADC) for Characterization and Differentiation of Focal Hepatic Lesions in Noncirrhotic Patients.

PURPOSE Diffusion-weighted imaging (DWI) is a MRI technique that, although relatively recent, has shown promise for the evaluation of focal hepatic lesions, providing information both on qualitative and quantitative parameters. The present study was designed to analyze the role of DWI, particularly the ADC (apparent diffusion coefficient), in differentiating benign solid liver lesions from malignant ones in a sample of noncirrhotic patients. METHODS We conducted a retrospective analysis of MRI scans performed at a tertiary hospital in Porto Alegre, Rio Grande do Sul, Brazil, from 2015 to 2018. The distribution of lesions into benign vs. malignant groups was determined by imaging criteria and/or histological analysis. ADC were obtained for each lesion.RESULTS Overall, 118 focal liver lesions were evaluated, with 78 benign and 40 malignant. The mean ADC value was 1.420×10−3 mm2/s for benign lesions versus 1.130×10−3 mm2/s for malignant lesions (p<0.001). ROC curve analysis showed an area under the curve of 0.79, optimal cutoff point of 1.19×10−3 mm2/s for discriminating between malignant and benign lesions, sensitivity and specificity of 75% and 73.1%.CONCLUSIONS We demonstrate the appropriateness of ADC for characterization of benign solid lesions of the liver and to distinguish these masses from malignant metastatic lesions.