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

ObjectiveTo correlate peripheral enhancement on contrast-enhanced computed tomography (CE-CT) of post-chemotherapy colorectal liver metastases (CRLM) patients with the pathological findings. MethodsForty-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. ResultsThe percentage of infarct-like necrosis was significantly higher in CRLM with smooth margins than in those 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). ConclusionsOur findings suggest that the type of necrosis is related to the nature of the margins, and the presence of residual cells are related to peripheral enhancement. Advances in knowledgeIn CRLM, following chemotherapy, the presence of residual cells and dangerous haloes is related to the contrast effect of the tumor margins, suggesting that tumor angiogenesis affects the contrast effect.