CT contrast enhancement of kidney V2 carcinoma after norepinephrine and acetylcholine injection.

CT attenuation values of kidney V2 carcinomas and normal kidneys in 15 rabbits were obtained before and after the simultaneous administration of an intravenous bolus infection of diatrizoate and an intraarterial bolus injection of norepinephrine or acetylcholine. After 6 micrograms norepinephrine, peak V2 density was 15 Hounsfield units (HU) less and renal cortex peak density 41 HU less than baseline, which resulted in a decrease in V2 contrast enhancement. After 20 micrograms acetylcholine, peak V2 density was 10 HU less and renal cortex peak density 13 HU less than baseline; the magnitude of contrast enhancement remained essentially unchanged.