Optimizing CT portography: a prospective comparison of injection into the splenic versus superior mesenteric artery.

Abstract

To evaluate whether computed tomographic arterial portography (CTAP) is best performed with injections in the superior mesenteric artery (SMA) or the splenic artery. Seventy-one studies were performed with injection into the SMA (n = 37) or splenic artery (n = 34) of 150 mL of contrast material at 1.5 mL/sec and 20-second delay for both groups. Images were reviewed for location and type of nontumoral perfusion abnormalities. The degree of liver parenchymal enhancement with each technique was compared. Fewer nontumoral perfusion defects were seen with splenic artery (65%) versus SMA (78%) injection. Visual differences in contrast enhancement with greater attenuation in dependent portions of the liver were seen with greater frequency with SMA (41%) than with splenic artery (24%) injection. Contrast enhancement that obscured detail in the right lobe was seen only with SMA injections (16%). Greater parenchymal enhancement (up to 18 HU) at all time intervals was seen with splenic artery injection. Because of greater parenchymal enhancement and fewer nontumoral perfusion abnormalities, splenic artery catheterization is the preferred technique for CTAP.