Evaluation of peripheral enhancement on contrast-enhanced computed tomography and corresponding pathological findings in colorectal liver metastases after preoperative chemotherapy

PURPOSE: To correlate peripheral enhancement on contrast-enhanced computed tomography (CE-CT) in patients with post-chemotherapy colorectal liver metastases (CRLM) with the corresponding pathological findings. MATERIAL AND METHODS: Forty-four patients with CRLM who underwent hepatic resection after preoperative chemotherapy between 2008 and 2013 were included. Two radiologists blinded to the histopathology findings performed a consensus categorization of the marginal contrast effects of CRLM on CE-CT as follows: Group 1, smooth margin without enhancement; Group 2, smooth margin with an enhanced rim; and Group 3, fuzzy margin with/without an enhanced rim. The Kruskal-Wallis test was used to compare the imaging findings with the histological findings. RESULTS: The percentage of infarct-like necrosis was significantly higher in those with CRLM with smooth margins than in those with CRLM with fuzzy margins (p < 0.001, r = 0.62). The percentage of viable cells was lowest in CRLM with smooth margins without enhancement (p < 0.001, r = 0.60). CONCLUSIONS: Our findings suggest that the type of necrosis is related to the nature of the margins, and the presence of residual cells is related to peripheral enhancement.