Role of Diffusion-Weighted Magnetic Resonance Imaging in The Assessment of Post-Management Viability of Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is one of the most prevalent primary liver cancers. While surgical resection and liver transplantation offer curative potential, many patients are ineligible and instead undergo locoregional therapies such as radiofrequency ablation (RFA), microwave ablation (MWA), or transarterial chemoembolization (TACE). Diffusion-weighted magnetic resonance imaging (DW-MRI) can detect tumor microscopic changes by evaluation of water molecules diffusion.Aim: To assess the role of DW-MRI in assessing post-treatment viability of HCC following RFA, MWA, and TACE.Patients and Methods: This retrospective research involved 50 patients (34 males, 16 females) with liver cirrhosis due to viral hepatitis and confirmed HCC. The patients underwent locoregional therapies (RFA, MWA, or TACE) between April 2023 and October 2024. All patients underwent dynamic contrast-enhanced MRI and DW-MRI. Lesions were analyzed for enhancement patterns, signal characteristics, and apparent diffusion coefficient (ADC) values.Results: Of the 50 treated lesions, 35 (70%) were classified as ablated (non-enhancing) and 15 (30%) as residual (enhancing). DW-MRI exhibited free diffusion in 31 lesions (62%) and restricted diffusion in 19 lesions (38%). The mean ADC value for ablated lesions was 1.56 ± 0.30 ×10⁻³ mm²/sec, compared to 0.81 ± 0.18 ×10⁻³ mm²/sec in residual lesions (p ≤ 0.05). DW-MRI exhibited sensitivity of 86.7%, and specificity of 82.8%. The best ADC cut-off value for predicting viable tumor was ≤1.117 ×10⁻³ mm²/sec.Conclusion: Dynamic MRI is more precise than DW-MRI for assessing HCC post-treatment viability, acting as the primary tool for detecting recurrent lesions. However, DW-MRI provides additional value by revealing tissue molecular properties, with ADC values helping differentiate between malignant recurrence and benign post-treatment changes. Therefore, the integration of dynamic MRI and DW-MRI offers a comprehensive approach for early assessment following locoregional therapies in HCC.