Color Doppler ultrasonography in the diagnosis of portal vein invasion in patients with pancreatic cancer.

We retrospectively evaluated the diagnostic usefulness of color Doppler ultrasonography for detecting portal vein invasion in 21 patients with pancreatic cancer who underwent surgical exploration (14 resection, seven inspection). Real-time gray scale ultrasonography, color Doppler ultrasonography, computed tomography, and angiography were performed in all patients to evaluate portal vein invasion, and the images were compared with the histopathologic or surgical inspection findings. On comparison between gray scale ultrasonographic and color Doppler ultrasonographic images, the tumor-vessel relations were visualized more clearly on color Doppler ultrasonography than on gray scale ultrasonography in 14 (22.2%) of 63 vessels. The sensitivity of color Doppler ultrasonography, computed tomography, and angiography for diagnosing portal invasion was 73.7%, 73.7%, and 73.6%, and the specificity was 95.1%, 95.5%, and 90.9%, respectively; the overall accuracy was 84.1%, 88.9% and 85.7%, respectively. A mosaic signal pattern was observed in 12 vessels and showed an accuracy of 86.4% for diagnosing portal vein invasion. In conclusion, compared with gray scale ultrasonography, color Doppler ultrasonography provided improved images of the tumor and portal vein. Furthermore, the accuracy of color Doppler evaluation of portal vein invasion appears to be equal to that of computed tomography and angiography. Therefore, color Doppler ultrasonography may play an important role as an initial examination for evaluating portal vein invasion.