Abstract: Objective This study aimed to investigate and summarize magnetic resonance imaging (MRI) feature in patients with primary liver cancer (PLC) and radiation-induced liver injury RILI) after three-dimensional conformal radiotherapy (3D-CRT). Methods A total of 92 patients with PLC were encountered in our hospital between January 2023 and September 2025, and all received 3D-CRT therapy and underwent gadopentetate dimeglumine (Gd-DTPA)-enhanced MRI scan. MRI signal, dynamic contrast-enhancement patterns, distribution morphology, diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values were recorded. Results By end of radiotherapy, RILI occurred in 22 cases (23.9%); tumor volume, doses of radiation, target volume and mean hepatic doses of radiation in patients with RILI were all greater than in those without RILI(P<0.05); percentages of hypointensity on T1-weighted imaging, hyperintensity on T2-weighted imaging, abnormal enhancement at arterial phase, decreased enhancement at portal venous phase and persistent hypointensity at delayed phase in lesions in patients with RILI were 77.3%, 86.4%, 81.8%, 72.7% and 68.2%, all significantly greater than 27.1%, 30.0%, 20.0%, 25.7% and 17.1%(P<0.05) in those without RILI; percentages of wedge-shaped distribution, insistency of enhanced area with radiotherapy dose distribution, distributed along hepatic segments or vascular courses and hyperintensity on DWI in patients with RILI were 86.4%, 90.9%, 68.2% and 81.8%, all much greater than 15.7%, 12.9%, 14.3% and 28.6%(P<0.05) in those without RILI; ADC value in patients with RILI was (1.5±0.2)×10^-3mm²/s, much greater than [(1.2±0.2)×10^-3mm²/s, P<0.05] in those without RILI. Conclusion Patients with PLC and RILI could have special MRI features, which might help clinicians make diagnosis and managements.

Key words: Hepatoma, Three-dimensional conformal radiotherapy, Radiation-induced liver injury, Enhanced MRI scan, Feature