Accuracy of preoperative imaging of hepatic tumors with helical computed tomography

Background: The accuracy of preoperative computed tomography (CT) scans in the era of modern imaging techniques with helical, high-resolution CT has not been adequately assessed. We reviewed the data from our departmental prospective database with the hypothesis that intraoperative ultrasonography (IOUS) still detects more hepatic tumors than are evident on preoperative helical CT scans. Methods: All patients who underwent surgical resection and/or radiofrequency ablation of primary or metastatic hepatic tumors between January 2001 and July 2002 were included in the review. All patients had preoperative helical CT imaging followed by hepatic IOUS. The number of malignant lesions and evidence of local disease identified by the preoperative CT scan versus IOUS and surgical exploration were compared. Results: In this time period, 250 patients underwent surgical resection and/or radiofrequency ablation of hepatic tumors. In 67 (27%) of these patients, IOUS identified more hepatic tumors than were seen on preoperative helical CT scan. In eight patients (3%), CT underestimated local extension of the disease into the diaphragm. The incidence of inaccurate preoperative prediction of the extent of disease increased significantly with a greater number of hepatic tumors. Conclusions: IOUS identified additional hepatic tumors in 27% of patients who underwent hepatic resection after state-of-the-art preoperative CT imaging. This study provides evidence that IOUS remains an essential part of the complete assessment of hepatic malignancies in patients who receive surgical treatment.