RESUMO
Objective:To evaluate the diagnostic efficacy of contrast enhanced computed tomography (CT) at early arterial phase and late arterial phase for detecting pancreatic carcinoma with small liver metastases (<1 cm).Methods:The enhanced CT data of 93 patients with pathologically confirmed pancreatic carcinoma admitted in the First Affiliated Hospital of Nanjing Medical University were retrospectively analyzed. The patients were randomly divided into the early arterial phase group (47 patients with the early arterial phase and portal venous phase scanning) and the late arterial phase group (46 patients with the late arterial phase and portal venous phase scanning) according to random number method. Number, maximum diameter, enhancement features of small liver metastases in two groups were observed. The receiver operating characteristic curve (ROC) was drawn and the area under the curve was calculated. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were also evaluated.Results:In the early arterial phase group, 21 of 47 patients had 28 small liver metastases with the maximum diameter of (7.33±1.40)mm. And in the late arterial phase group, 20 of 46 patients had 29 small liver metastases with the maximum diameter of (7.69±1.67)mm. There was not significantly statistical difference between the two groups ( P>0.05). Small liver metastases were more likely to present rim enhancement at the late arterial phase (69.0%). The area under curve of ROC of diagnostic performance in the early and late arterial phase were 0.657(95% CI 0.531-0.782), 0.810(95% CI 0.672-0.947), respectively. For the early phase group, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 68.1%, 61.9%, 75.0%, 88.5%, 42.9%, respectively. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value in the late group were 82.6%, 65.7%, 100%, 100%, 75.8%, respectively. Compared with the early arterial phase group, the late arterial phase group showed higher performance in detecting small liver metastases. Conclusions:Enhanced CT at the late arterial phase improves the detection of small liver metastases in patients with pancreatic carcinoma, aiding in accurate staging preoperatively.