title: Step-and-shoot prospectively ECG-gated vs. retrospectively ECG-gated with tube current modulation coronary CT angiography using 128-slice MDCT patients with chest pain: diagnostic performance and radiation dose.
abstract: BACKGROUND
  With increasing awareness for radiation exposure, the study of diagnostic accuracy of coronary CT angiography (CCTA) with low radiation dose techniques is mandatory to both radiologist and clinician.
  
  
  OBJECTIVE
  To compare diagnostic performance and effective radiation dose between step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with tube current modulation (TCM) CCTA using 128-slice multidetector computed tomography (MDCT).
  
  
  METHODS
  We retrospectively evaluated 60 patients who underwent CCTA with either of two different low-dose techniques using 128-slice MDCT (23 patients for step-and shoot-prospectively ECG-gated and 37 patients for retrospectively ECG-gated with TCM CCTA) followed by conventional coronary angiography. All coronary arteries and all segments thereof, except anatomical variants or small size (< 1.5 mm) ones, were included in analysis.
  
  
  RESULTS
  In per-segment analysis, sensitivity, specificity, positive predictive value, and negative predictive value were 91/96%, 95/94%, 75/73%, and 98/99% for step-and-shoot prospectively ECG-gated and retrospectively ECG gated with TCM CCTA, respectively, relative to conventional coronary angiography. Effective radiation dose were 1.75 ± 0.83 mSv, 4.91 ± 1.71 mSv in the step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with TCM CCTA groups, respectively.
  
  
  CONCLUSIONS
  The two low-radiation dose CCTA techniques using 128-slice MDCT yields comparable diagnostic performance for coronary artery disease in symptomatic patients with low heart rates.
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine and Medical Research Institute, Pusan National University Yangsan Hospital, Korea.
authors.forename: Jeong Su
authors.initials: JS
authors.lastname: Kim
authors.forename: Ki Seok
authors.initials: KS
authors.lastname: Choo
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Jeong
authors.forename: Kook Jin
authors.initials: KJ
authors.lastname: Chun
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Park
authors.forename: Sung Gook
authors.initials: SG
authors.lastname: Song
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Park
authors.forename: June Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Jun
authors.initials: J
authors.lastname: Kim
authors.forename: Dongcheul
authors.initials: D
authors.lastname: Han
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Lim
mesh_terms: D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D002637:Chest Pain / Q000000981:diagnostic imaging*; D016009:Chi-Square Distribution; D017023:Coronary Angiography / Q000379:methods*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*