title: DNA damage in lymphocytes induced by cardiac CT and comparison with physical exposure parameters.
abstract: OBJECTIVE
  To investigate whether physical exposure parameters such as the dose index (CTDI), dose length product (DLP), and size-specific dose estimate (SSDE) are predictive of DNA damage.
  
  
  METHODS
  In vitro, we scanned a phantom containing blood samples from five volunteers at CTDI 50, 100, and 150 mGy. One sample was not scanned. We also scanned samples in three different-size phantoms at CTDI 100 mGy. In vivo, we enrolled 45 patients and obtained blood samples before and after cardiac CT. The γ-H2AX foci were counted.
  
  
  RESULTS
  In vitro, in the control and at CTDI 50, 100, and 150 mGy, the number of γ-H2AX was 0.94 ± 0.24 (standard error, SE), 1.28 ± 0.30, 1.91 ± 0.47, and 2.16 ± 0.20. At SSDE 180, 156, and 135 mGy, it was 2.41 ± 0.20, 1.91 ± 0.47, and 1.42 ± 0.20 foci/cell. The γ-H2AX foci were positively correlated with the radiation dose and negatively correlated with the body size. In vivo, the γ-H2AX foci were significantly increased after CT (from 1.21 ± 0.19 to 1.92 ± 0.22 foci/cell) and correlated with CTDI, DLP, and SSDE.
  
  
  CONCLUSIONS
  DNA damage was induced by cardiac CT. There was a correlation between the physical exposure parameters and γ-H2AX.
  
  
  CONCLUSIONS
  • DNA damage was induced by radiation exposure from cardiac CT. • The γ-H2AX foci number was correlated with the CT radiation dose. • Physical exposure parameters reflect the DNA damage by CT radiation exposure.
authors: Department of Diagnostic Radiology, Institute of Biomedical Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. wfukumoto@hiroshima-u.ac.jp.
authors: Wataru
authors: http://orcid.org/0000-0001-7645-8446
authors: W
authors: Fukumoto
authors: Department of Cardiovascular Physiology and Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors: Mari
authors: M
authors: Ishida
authors: Department of Cardiovascular Physiology and Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors: Chiemi
authors: C
authors: Sakai
authors: Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
authors: Satoshi
authors: S
authors: Tashiro
authors: Institute of Clinical Research West Medical Center, Hiroshima, Japan.
authors: Takafumi
authors: T
authors: Ishida
authors: Department of Cardiovascular Medicine, Hiroshima University Hospital, Hiroshima, Japan.
authors: Yukiko
authors: Y
authors: Nakano
authors: Department of Diagnostic Radiology, Institute of Biomedical Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan.
authors: Fuminari
authors: F
authors: Tatsugami
authors: Department of Diagnostic Radiology, Institute of Biomedical Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan.
authors: Kazuo
authors: K
authors: Awai
mesh_terms: D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging; D049628:Body Size; D004249:DNA Damage; D005260:Female; D006657:Histones / Q000032:analysis / Q000187:drug effects; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D000069079:Radiation Exposure; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: C468783:H2AX protein, human; D006657:Histones
keywords: CT dose index; Computed tomography; DNA; Size-specific dose estimates; γ-H2AX