Ultrasonography of the pancreas. 3. Doppler imaging

Ultrasonography is probably the most widely used medical imaging technique. In fact, its non-invasivity, portability, widespread distribution and good clinical results have made it the preferred method for a first imaging approach to patients in a large variety of clinical settings. Ultrasound technology is advancing rapidly, aimed to increase image quality. In particular, increased color-Doppler sensitivity is contributing to the diagnosis and staging of pancreatic disease. Doppler studies are in fact integral part of ultrasound examination of the pancreas evaluating the peripancreatic vascular structures enclose portal vein, splenic artery and vein, superior mesenteric artery and vein, aorta, and inferior vena cava. While flows in all peri-pancreatic vessels are well recognized, only few parenchymal vessels are usually appreciable in normal conditions. Anyway the increased Doppler sensitivity allows the visualization of smaller peri-pancreatic and intra-pancreatic vessels. This article will review the technical background underlying the clinical application of Doppler ultrasonography in pancreatic imaging, with particular emphasis to normal vascular anatomy of the pancreas, and to the main applications of Doppler techniques in the different pancreatic pathologies.