Portosystemic collaterals in portal hypertension: visualization by using blood-pool SPECT imaging

Single-photon emission CT (SPECT) was performed with technetium-99m autologous RBCs in 11 patients with chronic hepatitis and in 46 cirrhotic patients with portal hypertension to determine the value of the procedure for identifying portosystemic collateral blood flow. Twenty millicuries (740 MBq) of 99mTc-RBCs, labeled by an in vivo technique, were given IV, and tomographic imaging of the intraabdominal vascular blood pool was performed. Fourteen patients with cirrhosis also had arterial portography, and 37 had scintiphotosplenoportography. In 38 of 46 patients with cirrhosis, SPECT images showed portosystemic collaterals. The coronary vein was seen in 52% of the patients, the short gastric vein in 11%, the gastrorenal or splenorenal shunt in 24%, the umbilical vein in 11%, and the anterior abdominal wall vein in 17%. Portosystemic collaterals were not shown in any of the patients with chronic hepatitis. Collaterals were identified on SPECT images in 10 of 11 patients in whom collaterals were documented by arterial portography and in all 28 patients in whom collaterals were shown by scintiphotosplenoportography. Furthermore, SPECT clearly showed a patent portal vein in three patients and the coronary vein in two patients, when these veins were not identified by means of scintiphotosplenoportography. This experience suggests that SPECT is useful for the noninvasive identification of portosystemic collaterals in patients with portal hypertension.