Aortic and hepatic enhancement and tumor-to-liver contrast: analysis of the effect of different concentrations of contrast material at multi-detector row helical CT.
OBJECTIVE
To investigate the effect of different iodine concentrations of contrast material on aortic and hepatic enhancement and the detectability of hypervascular hepatocellular carcinoma (HCC) with multi-detector row computed tomography (CT) and a uniphasic contrast material injection technique.


METHODS
Two hundred one patients with known or who were suspected of having HCC underwent multi-detector row CT; 58 patients with hypervascular HCC were identified. First-, second-, and third-phase scanning was started with the aortic arrival times plus 15 seconds, plus 30 seconds, and plus 105 seconds, respectively. All patients were assigned randomly into two groups. Patients in groups A and B received iopamidol with an iodine concentration of 300 mg/mL and 370 mg/mL, respectively, with the same total iodine load per patient per body weight. The liver and aorta enhancement and tumor-to-liver contrast (TLC) were measured. Depiction of hepatic arteries was evaluated visually by two radiologists.


RESULTS
During the first phase, aortic enhancement was significantly (P <.01) higher in group B, with no significant difference in hepatic enhancement between the two groups. During the second phase, aortic enhancement was significantly (P <.01) higher in group A, with no significant difference in hepatic enhancement. The TLC was significantly (P <.01) higher in group B during the first phase, but there was no significant difference between the two groups during the second phase. There was no significant difference in any parameters between the two groups during the third phase. Depiction of the hepatic arteries in group B was significantly (P <.05) superior to that in group A.


CONCLUSIONS
In the arterial phase, administration of a higher concentration of contrast material is effective for a significantly higher TLC.
Department of Radiology, Rinku General Medical Center, 2-23 Rinkuorai-kita, Izumisano City, Osaka 598-8577, Japan.
Kazuo
K
Awai
Koichi
K
Takada
Hiromitsu
H
Onishi
Shinichi
S
Hori
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001027:Aortography / Q000379:methods*; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007455:Iodine / Q000008:administration & dosage; D007479:Iopamidol; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007455:Iodine; D007479:Iopamidol