Incidentally Detected Liver Metastases during Pancreas Contrast-enhanced Ultrasound

Purpose: The purpose of current study was to investigate the value of the late-phase enhancement features of pancreas contrast-enhanced ultrasound (CEUS) in the detection of liver metastases in patients with pancreatic ductal adenocarcinomas (PDAC).Methods: From October 2020 to March 2021, 86 patients were prospectively enrolled. The gold standard of liver metastatic and PDAC lesions were based on histopathologically diagnoses and multiple imaging modalities results. B-mode ultrasound (BMUS) was performed to detect suspected liver metastases before CEUS. During the late phase of pancreas CEUS, the entire liver was scanned again to detect hypoenhanced liver metastases. Liver metastases were confirmed by biopsy and histopathological results. The number and size of liver metastases detected by BMUS and during CEUS late phase were recorded and compared.Results: Suspected liver metastases were detected in 14 patients by BMUS (n = 23). During the late phase of CEUS, hypoenhanced liver metastases were detected in 23 patients (n = 87). When compared with BMUS, whole-liver scan during the late phase of CEUS detected more isoechoic, small, or superficially located lesions. Compared with BMUS, the specificity, sensitivity, positive predictive value, and negative predictive value of CEUS in diagnosing of liver metastases in PDAC patients were significantly improved (96.72% vs. 100%, 48% vs. 92%, 85.71% vs. 100%, and 83.10% vs. 96.83%, respectively) (P < 0.05).Conclusion: The late phase whole liver scan during CEUS of pancreas helps to detect more liver metastases, which is important for further clinical decision-making.