CT arterial portography of the abdomen: effect of injecting papaverine into the mesenteric artery on hepatic contrast enhancement.

Objective: The purpose of this study was to determine the effect of precontrast injection of papaverine hydrochloride into the superior mesenteric artery on the degree of contrast enhancement of the hepatic parenchyma during CT arterial portography (CTAP, CT with injection of contrast material into the superior mesenteric artery).

Subjects And Methods: Twenty-two patients were included in this study. All patients had a baseline unenhanced CT scan and then had CTAP performed with transcatheter injection of 150 ml of nonionic iodinated contrast material (30 g iodine/100 ml) at a rate of 2 ml/sec. Eleven patients received a precontrast injection of 40 mg of papaverine hydrochloride via catheter into the superior mesenteric artery, and 11 patients had CTAP without papaverine hydrochloride. Attenuation of the liver was measured before and after contrast administration in both groups of patients. For each CTAP section, the absolute hepatic enhancement (postcontrast attenuation--precontrast attenuation) and the relative hepatic enhancement ([absolute hepatic enhancement/precontrast attenuation] x 100) were calculated. Also, the mean absolute enhancement and the mean relative enhancement for the entire liver were calculated for each patient.

Results: The mean relative enhancement (+/- SD) of hepatic parenchyma was 192 +/- 54% with papaverine hydrochloride and 146 +/- 26% without papaverine hydrochloride. Relative enhancement was significantly higher when papaverine hydrochloride was used (p < .02). The mean absolute enhancement (+/- SD) of hepatic parenchyma was 123 +/- 25 H with papaverine hydrochloride and 91 +/- 19 H without papaverine hydrochloride. Absolute enhancement was significantly higher in patients who had papaverine hydrochloride (p < .01).

Conclusion: The results show that precontrast transcatheter infusion of papaverine hydrochloride increases the degree of contrast enhancement of the liver during CTAP.