Hepatic steatosis assessment with CT or MRI in patients with colorectal liver metastases after neoadjuvant chemotherapy
Purpose: Preoperative radiological assessment of hepatic steatosis is recommended in patients undergoing a liver resection, but few studies investigated the diagnostic accuracy after neoadjuvant chemotherapy. The aim of this study was to compare diagnostic accuracy of preoperative CT or MRI measurements of steatosis in patients with colorectal liver metastases after induction chemotherapy. Methods: MRI measurements (relative signal intensity decrease; RSID), N = 36, and CT scan measurements (Hounsfield units; HU), N = 32, were compared with histological steatosis assessment. Diagnostic accuracy was determined for detecting any (>5%) or marked macrovesicular steatosis (>33%). Results: MRI showed the highest correlation with histology (r = 0.82, P < 0.001), compared to CT measurements (r = -0.65, P < 0.001). Based on linear regression analysis, radiological cut-off values for 5% and 33% macrovesicular steatosis, corresponded to 0.7% and 19.2% RSID in the MRI-group, and 60.4 and 54.2 HU in the CT-group, respectively. Sensitivity and specificity for the detection of any and marked macrovesicular steatosis using MRI was 87% and 69%, and 78% and 100%, respectively, and for CT, 83% and 64%, and 70% and 87%, respectively. Conclusion: In patients treated with neoadjuvant chemotherapy MRI measurements of steatosis showed the highest correlation coefficient and the best diagnostic accuracy, as compared to CT measurements.