title: Late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner in patients without circulatory disturbances: automatic bolus tracking or empirical scan delay?
abstract: The value of automatic bolus tracking in late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner as compared with fixed time-delay examination in patients without circulatory disturbances is evaluated. For the evaluation of known or suspected liver disease, 98 multiphase contrast-enhanced CT examinations including double late-arterial phase imaging were randomized into either scanning with a scan delay of 30 s from the beginning of contrast material injection or scanning with automatic bolus tracking. Contrast material was injected at 0.07 ml/kg body weight/s over 30 s. Contrast enhancement in each acquisition was measured in the aorta, portal vein, liver, pancreas and hepatocellular carcinomas. The density difference between hepatocellular carcinomas and the hepatic parenchyma was calculated. The mean time to the first-pass acquisition as determined by automatic bolus tracking was 29.6 s. No statistically significant difference was observed between the two groups either in any enhancement in any acquisition or in the lesion-to-liver density difference. The use of automatic bolus tracking in late-arterial and portal-venous phase hepatic CT does not significantly improve the degree of contrast enhancement in the aorta, portal vein, liver and pancreas or lesion-to-liver conspicuity in patients without circulatory disturbances.
authors.affiliation: Department of Technical Radiology, Nagoya University School of Health Sciences, Daikou-minami 1-1-20, Higashi-ku, 461-8673 Nagoya, Japan. shigeito@met.nagoya-u.ac.jp
authors.forename: Shigeki
authors.initials: S
authors.lastname: Itoh
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ikeda
authors.forename: Masataka
authors.initials: M
authors.lastname: Achiwa
authors.forename: Hiroko
authors.initials: H
authors.lastname: Satake
authors.forename: Shingo
authors.initials: S
authors.lastname: Iwano
authors.forename: Takeo
authors.initials: T
authors.lastname: Ishigaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001027:Aortography; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D010179:Pancreas / Q000000981:diagnostic imaging; D011172:Portography; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D013997:Time Factors; D036542:Tomography, Spiral Computed
chemical_list: D003287:Contrast Media