Multidetector multiphase contrast-enhanced liver CT: prospective study comparing two contrast material injection rates on vascular and liver parenchyma enhancement in patients with varied cirrhotic status

BACKGROUND: To compare 2 rates of contrast material injection, with dose tailored to patient body weight (bw) and automatic bolus triggering system, on vascular and liver parenchyma enhancement at multidetector multiphase contrast-enhanced liver computed tomography (CT) of patients with varied cirrhotic status. METHODS: One hundred and thirty consecutive patients with varied cirrhotic status, referred for contrast-enhanced liver CT evaluation of focal liver nodule(s), were prospectively and randomly assigned to 1 of 2 routine contrast-enhanced liver CT protocols: 2 mL/kg of bw of a nonionic contrast agent (300 mg I/mL) injected at a 3 mL/sec, versus 2 mL/kg of bw of the same contrast agent injected at 4 mL/sec. Quantitative vascular and liver parenchyma enhancements were obtained. Attenuation values of the abdominal aorta during the arterial phase CT, of the main portal vein during the portal venous phase CT, and of the liver parenchyma during the arterial, the portal venous, and the equilibrium phases liver CT, were compared with multiple 2-way analysis of variance. RESULTS: Significantly higher attenuation values were noted in the abdominal aorta with a 4-mL/sec-flow rate. Attenuation values were not significantly different in the portal vein and in the liver parenchyma, whatever was the patient cirrhotic status. CONCLUSIONS: With dose tailored to body weight and automatic bolus triggering system, adjusting flow rate makes no difference in patients with regard to liver or portal vein enhancement, regardless of presence/absence of cirrhosis.