Duygu KARAHACIOĞLU, Hande ÖZEN ATALAY
Journal of Health Sciences and Medicine - 2026;9(5):1219-1224
Aims: To evaluate the frequency of typical magnetic resonance imaging (MRI) signal characteristics of colorectal liver metastases (CRLM) before and after chemotherapy using gadoxetic acid-enhanced MRI. Methods: Forty-four patients (29 male, 15 female; median age 61 years, IQR 52-69) who underwent gadoxetic acid-enhanced MRI for CRLM between January 2020 and November 2022 were retrospectively evaluated. Mucinous/cystic lesions and poor-quality examinations were excluded. A maximum of 5 lesions per patient were assessed (75 pre-chemotherapy, 125 post-chemotherapy; 200 total). T2-weighted (T2W), diffusion-weighted (DWI), contrast-enhanced T1-weighted (CE-T1W), and hepatobiliary phase (HBP) image features were recorded. Chi-square, Fisher exact, and McNemar tests were used. Results: Pre-chemotherapy, moderate T2W hyperintensity was present in 93.3%, diffusion restriction in 81.3%, ring enhancement in 56.0%, and HBP hypointensity in 100% of lesions. Post-chemotherapy, these rates changed to 68.8% (p=0.0002), 37.6% (p<0.001), 35.2% (p=0.016), and 96.8% (p=0.299), respectively. Peripheral HBP hyperintensity increased from 1.3% to 10.4% (p=0.019). Paired McNemar analysis (n=17 patients) confirmed significant reductions in DWI restriction (80.4% vs. 42.9%, p<0.001), moderate T2W hyperintensity (98.2% vs. 69.6%, p<0.001), ring enhancement (55.4% vs. 25.0%, p=0.001), and targetoid appearance (46.4% vs. 26.8%, p=0.027). Conclusion: Typical gadoxetic acid-enhanced MRI features of CRLM decrease significantly after chemotherapy. HBP hypointensity is largely preserved and remains the most reliable feature for lesion detection. Awareness of post-treatment imaging changes is essential for accurate response assessment.
