Intraoperative ultrasound of the liver in primary and secondary hepatic malignancies: comparison with preoperative 1.5-T MRI and 64-MDCT

Abstract

Objective: The purpose of this study is to compare intraoperative ultrasound and preoperative contrast-enhanced MRI or 64-MDCT for the depiction of malignant lesions and for prediction of hepatic segments positive and negative for malignancy in patients undergoing partial hepatic resection.

Materials and methods: In this retrospective study, 292 patients undergoing hepatic resection for metastatic colorectal cancer (n = 168), hepatocellular carcinoma (n = 70), or other hepatic malignancies (n = 54) were included. The sensitivity and negative predictive value of intraoperative ultrasound and preoperative cross-sectional imaging were calculated. The mean (± SD) time intervals to surgery were 37.6 ± 26 days for 64-MDCT and 48.1 ± 34 days for MRI. Surgical histopathologic examination was the reference standard. Changes in surgical management were recorded. Logistic regression models were used to estimate and compare proportions.

Results: For all 561 malignant lesions, the sensitivity of intraoperative ultrasound was 95.1%, compared with 96.8% for 64-MDCT (p = 0.025) and 94.4% for MRI (p = 0.960); 64-MDCT was also more sensitive than intraoperative ultrasound in identifying positive liver segments (p = 0.013). After controlling for patient group and time interval between imaging and surgery, the negative predictive value of 64-MDCT and MRI was higher than that of intraoperative ultrasound (p < 0.001 and p = 0.040, respectively). In only eight cases (2.7%) was surgical management changed after intraoperative ultrasound.

Conclusion: For patients undergoing partial liver resection for hepatic malignancies, 64-MDCT and MRI have an equivalent or higher sensitivity in identifying hepatic segments with malignancy, and both 64-MDCT and MRI appear to have a higher predictive value for identifying disease-free segments than does intraoperative ultrasound.