Normal and abnormal upper abdominal venous structures as seen by ultrasound.

Recent B-scan ultrasonic techniques have made possible the routine visualization of the major upper abdominal venous structures. Real-time scanning permits in vivo dynamic assessment of the upper abdominal veins. B-scan ultrasound allows optimal anatomic resolution and is superior for the establishment of intraluminal pathology and anatomic relationships with adjacent organs. The anatomic localization of the upper abdominal veins has proved of practical importance in several ways. Identification of the splenic and superior mesenteric veins allows localization of the pancreas and the enlarged common bile duct. Increased size of the upper abdominal venous structures can indicate certain pathological conditions, notably raised right heart pressure and portal hypertension. Intrinsic pathology within the inferior vena cava may be detected. Extrinsic distortion of veins by adjacent mass lesions is not uncommon, and if the venous structure is recognized, more precise anatomic localization of the mass is possible.