Background/aims: Since there is a difference in the slice thickness between preoperative images of liver metastases (1-3mm slices) and surgical liver pathology specimens (5mm slices), micrometastases may not be detected in these specimens. In addition, the accuracy of preoperative imaging for the detection of metastases degenerated by chemotherapy is unclear.
Methodology: Five patients with liver metastases from colorectal cancer who had received adjuvant chemotherapy and undergone hepatectomy were included. The whole resected liver was sliced at approximately 1mm intervals and the slices were examined carefully for gross lesions. The preoperative CT and EOB-MRI findings of each lesion were compared with gross and histopathological findings.
Results: The accuracy of EOB-MRI was higher than that of CT for the detection of liver metastases. The number of lesions detected on EOB-MRI was in agreement with that of histopathologically proven liver metastases in 4 of the 5 patients. All lesions that were grossly identified but turned out to be non-neoplastic were regenerative nodules associated with drug-induced liver injury or lobular nodules associated with marked fatty change, measuring about 1mm in diameter.
Conclusions: EOB-MRI was the most accurate method for the preoperative detection of liver metastases, enabling the visualization of almost all liver metastases.