Portosystemic shunt on CT during arterial portography: prevalence in patients with and without liver cirrhosis

Background To review various portosystemic shunts (PS) and to evaluate their prevalence by CT during arterial portography (CTAP) using a multidetector-row CT (MDCT). Methods CTAP of 116 patients (liver cirrhosis 70 patients, non-liver cirrhosis 46 patients) was retrospectively reviewed. CTAP was performed with the catheter placed in the superior mesenteric artery using MDCT. Axial CT images of 0.625- and 3.75- or 2.5-mm thickness were obtained. Multiplanar reformation images and maximum intensity projection images were subjected to review. Results A part of the veins in the ileocecal region drained into the right renal vein or the inferior vena cava (IVC) via the right gonadal vein in 57 patients (81%). A part of the veins of the ascending colon drained via the right renal capsular vein into the IVC in 37 patients (53%). In 46 patients without liver cirrhosis, the right gonadal and right renal capsular veins were opacified on CTAP in 22 patients (48%) and 20 patients (43%), respectively. Conclusions Portosystemic shunts in retroperitoneum were frequently recognized on CTAP images in patients with liver cirrhosis. The right gonadal vein and the right renal capsular vein were the most frequent routes of the portosystemic shunts. They may exist in physiological condition.