Functional CT with an experimental intravascular contrast agent in the assessment of liver vascular physiology.

RATIONALE AND OBJECTIVES: We evaluated liver vascular physiology with a functional spiral computed tomography (CT) technique and an intravascular contrast agent. METHODS: Eleven rabbits were studied by means of continuous 40-second single-section data acquisition after bolus injection of an experimental contrast agent. Sequential images were reconstructed at 200-msec intervals. Aortic, portal and hepatic venous, and liver time-HU curves were obtained. From these, hepatic blood volume and flow, tissue transit times, and arterial and portal contributions to total liver blood supply were assessed. RESULTS: The following measures were obtained: hepatic blood volume fraction, 0.33 +/- 0.03 (mean +/- standard error); total flow, 241.1 mL/min +/- 33.6 per 100 g of tissue (arterial component, 11.3 mL/min +/- 3.0 per 100 g of tissue; portal component, 226.4 mL/min +/- 30.7 per 100 g of tissue); arterial transit time, 8.7 seconds +/- 1.6; portal transit time, 8.7 seconds +/- 1.3; arterial to portal perfusion ratio, 0.06 +/- 0.01; and calculated arterial and portal perfusion indexes, 0.05 +/- 0.01 and 0.95 +/- 0.01, respectively. CONCLUSION: Functional CT is a promising, high-resolution tomographic imaging technique for evaluating liver perfusion.