Benign Versus Malignant Solid Liver Lesions: How Can Apparent Diffusion Coefficient Value Be Added to the Differentiation?

Abstract

Purpose: To determine the efficacy of apparent diffusion coefficient (ADC) values and ratios (lesion/liver tissue, lesion/splenic tissue, lesion/paraspinal muscle) in differentiating benign from malignant solid liver lesions. Materials and Methods: This study retrospectively analyzed data from 115 patients with solid liver lesions who underwent abdominal magnetic resonance imaging (MRI) at a single institution between January 2023 and December 2024. Lesions were classified as benign or malignant based on biochemical tests as well as radiographic and/or histopathologic findings. ADC values and ratios were determined using a 1.5 T MRI scanner. Quantitative variables are presented as mean ± standard deviation or median (interquartile range). Receiver operating characteristic (ROC) analysis was used to determine the cut-off values for ADC value and ratio, for which associated areas under the ROC curve were calculated. Results: The present analysis included 115 lesions—36 benign and 79 malignant. The median ADC value of the benign lesions was significantly higher than that of malignant lesions: 1744.5 × 10-6 mm2/s vs. 1168.0 × 10-6 mm2/s, respectively. The average lesion-toliver ADC (rADCl), lesion-to-spleen ADC (rADCsp), and lesion-to-paraspinal muscle ADC (rADCm) ratios for the benign lesions were significantly higher than those of malignant lesions: 1.79 vs. 1.09, 2.31 vs. 1.44, and 1.19 vs 0.80, respectively. A threshold of 1416 × 10-6 mm2/s was used to differentiate benign vs. malignant lesions, with a sensitivity of 83.3% and a specificity of 78.5%. The cut-off values for rADCl, rADCsp, and rADCm were 1.55, 1.95, and 0.97, respectively, with sensitivities of 69.4%, 69.4%, and 83.3% and specificities of 87.3%, 91.1%, and 79.9%, respectively. Conclusion: ADC metrics obtained from diffusion-weighted MRI effectively distinguished benign from malignant solid liver lesions.