Detection of liver metastases in patients with pancreatic adenocarcinoma: MRI versus CT

Introduction. Detection of liver metastases is important to guide therapeutic management of pancreatic cancer. Data suggest that magnetic resonance imaging (MRI) is more sensitive than computed tomography (CT) for the diagnosis of liver metastases from pancreatic cancer. However, MRI is currently not recommended in several guidelines. Purpose. To compare the performance of CT vs MRI in detection of liver metastases in patients with pancreatic adenocarcinoma. Methods. This was a retrospective single-center study over 24 months from January 2020 to December 2021 of patients suspected of having PDAC. All patients underwent contrast-enhanced triple phase CT and contrast-enhanced MRI/MRCP. The CT and MRI assessment of resectability and detection of metastases were performed according to NCCN version 1.2024 criteria by one observer based on clinical report. Composite reference standard based on decision of operability (based on multidisciplinary tumor board decision), surgical findings (delay of 2 to 3 weeks after imaging) and histopathologic findings. Results. 117 patients (M/F 52/65, mean age 62±11y) were included. The mean tumor size was 43.6±15.2mm (add range). 42/46 patients (34.2%/39.3%) were diagnosed with metastatic disease on CT/MRI, 40/36 patients (34.2%/30.8%) were resectable, 20/16 patients (17.1%/13.7%) were borderline resectable and 15/19 patients (12.8%/16.2%) were locally advanced. The detection of liver metastases on CT and MRI was compared with surgical findings in 45 patients (38.5%). The analysis showed that MRI had superior performance to CT, with sensitivity at 100% vs 60% and specificity at 97.1% vs 97.1%, PPV at 90.9% vs 85.7% and NPV 100% vs 89.5% (MRI/CT). Conclusion. MRI is more sensitive than CT in detection of liver metastases in patients with pancreatic adenocarcinoma.