DETECTION OF HYPERVASCULAR MODULAR HEPATOCELLULAR CARCINOMAS - VALUE OF TRIPHASIC HELICAL CT COMPARED WITH IODIZED-OIL CT

OBJECTIVE. The objective of this study was to compare the capability o f arterial, portal venous, and delayed phases of helical CT with that of iodized-oil CT for revealing nodular hepatocellular carcinomas. MAT ERIALS AND METHODS. Forty-eight patients with nodular hepatocellular c arcinomas underwent triphasic helical CT examination with l0-mm collim ation at 10-mm/sec table speed. We injected 120 mi of contrast materia l (36 g of iodine) at the rate of 3 ml/sec. Arterial-phase, portal ven ous-phase, and delayed-phase images were obtained with 30-sec, 65-sec, and 360-sec delays, respectively. All 48 patients also underwent angi ography and intraarterial infusion of iodized oil after helical CT; io dized-oil CT was performed about 2 weeks after infusion of iodized oil . Helical CT images were compared with iodized-oil CT images for revea ling hepatic nodules. RESULTS. In 48 patients, 79 hepatocellular carci nomas were seen with iodized-oil CT. Using helical CT, the arterial ph ase revealed 68 lesions (86%), the portal venous phase revealed 53 les ions (67%), and the delayed phase revealed 57 lesions (72%). The arter ial phase proved superior to the portal venous and delayed phases for revealing lesions (p = .0025). The portal venous phase showed no signi ficant difference for revealing lesions compared with the delayed phas e. When combined, helical CIT of the arterial anl-l portal venous phas es revealed 73 lesions (92%); a combination of the arterial and delaye d phases revealed 72 lesions (91%); and a combination of the portal ve nous and delayed phases revealed 63 lesions (80%). Any combination of two phases that included the arterial phase proved superior to the com bination of the portal venous and delayed phases (p = .0033). Overall, the combination of the arterial and portal venous phases (92%) or the combination of all three phases (92%) proved best at revealing lesion s. CONCLUSION. The arterial phase of helical CT is better for revealin g nodular hypervascular hepatocellular carcinoma than are the portal v enous and delayed phases. The combination of the arterial and portal v enous phases is superior to the arterial phase alone. Also, the combin ation of the arterial and portal venous phases is equal to the combina tion of the three phases for revealing hypervascular hepatocellular ca rcinomas.