title: The Optimal Body Size Index with Which to Determine Iodine Dose for Hepatic Dynamic CT: A Prospective Multicenter Study.
abstract: OBJECTIVE
  To identify the body size parameter that exhibits the best correlation with aortic and hepatic enhancement at hepatic dynamic computed tomography (CT) in a large patient population enrolled in a multicenter study.
  
  
  METHODS
  This prospective study was approved by the ethics committee of each of the 31 participating institutions where 1342 patients were enrolled between April 2012 and September 2013. All patients provided either written or oral informed consent. All patients underwent hepatic dynamic CT, which included preenhanced, hepatic arterial phase (HAP), and portal venous phase (PVP) scanning, performed with the routine scanning protocol of each institution. Changes in CT number (in Hounsfield units) per gram of iodine in the aorta (eA/I) and liver (eL/I) during HAP and PVP scanning were recorded for each patient. Hierarchical multivariate linear regression analysis was performed in which the outcome variable was either eA/I or eL/I; the independent variables were age, sex, one body size parameter (height, body weight, body mass index, lean body weight [LBW], or body surface area), and liver function (aspartate aminotransferase, albumin, and total bilirubin levels). A two-level hierarchical model in which patients were level 1 and the institution was level 2 was used.
  
  
  RESULTS
  Hierarchical multivariate linear regression analysis revealed that in the population not stratified by sex, body size was significantly correlated with eA/I and eL/I (P < .001) and that LBW exhibited the strongest correlation with eA/I and eL/I (r = -0.561 and r = -0.601, respectively). Sex-stratified analysis showed that LBW was more strongly correlated with eA/I and eL/I in women (r = -0.779 and r = -0.948, respectively) than in men (r = -0.500 and r = -0.494, respectively) or in the nonstratified total population.
  
  
  CONCLUSIONS
  Among body size parameters, LBW exhibited the strongest correlation with aortic and hepatic enhancement, especially in women.
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanematsu
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Tonsok
authors.initials: T
authors.lastname: Kim
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Ichikawa
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakamoto
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yoshioka
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Teruhito
authors.initials: T
authors.lastname: Mochizuki
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Naofumi
authors.initials: N
authors.lastname: Matsunaga
authors.affiliation: From the Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan (K.A., Y.N.); Department of Radiology, Gifu University Hospital, Gifu, Japan (M.K.); Department of Radiology, Osaka University Graduate School of Medicine, Suita, Japan (T.K., A.N.); Department of Radiology, University of Yamanashi, Chuo, Japan (T.I.); Memorial Heart Center, Iwate Medical University, Morioka, Japan (K.Y.); Department of Radiology, Ehime University School of Medicine, Toon, Japan (T.M.); Department of Radiology, Yamaguchi University School of Medicine, Ube, Japan (N.M.); and Department of Diagnostic Radiology, Kumamoto University, Kumamoto, Japan (Y.Y.).
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049628:Body Size; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007455:Iodine / Q000008:administration & dosage*; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007455:Iodine