title: ECG-gated coronary angiography enables submillisievert imaging in invasive cardiology.
abstract: BACKGROUND
  The median dose area products (DAP) and effective doses (ED) of patients arising from coronary angiography (CA) are considerable: According the 2013 National German Registry, they amount to 19.8 Gy × cm(2) and 4.0 mSv, respectively.
  
  
  METHODS
  We investigated the feasibility of prospective electrocardiogram (ECG)-gated coronary angiography (CA)-a novel technique in invasive cardiology-with respect to possible reduction in irradiation effects. Instead of universally fix-rated radiographic acquisition within 7.5-15 frames/s, one single frame/heartbeat was triggered toward the diastolic moment immediately before atrial contraction (77 % of ECG-RR interval) most likely to provide motion-free and hence optimized resolution of the coronary tree. For 200 patients (body mass index 27.8 kg/m(2), age 67.5 years, male 55 %, 68 bpm) undergoing ECG-gated CA, we measured various median (interquartile range) parameters for radiation exposure.
  
  
  RESULTS
  The total DAP was 0.64 (0.46-1.00), radiographic fraction was 0.30 (0.19-0.43), and fluoroscopic fraction was 0.35 (0.21-0.57) Gy × cm(2). Radiographic imaging occurred within 21.7 s (17.1-26.3), with 25 frames (20-30) over the course of 7 runs (6-8). Fluoroscopy time was 119 s (94-141). Radiographic DAP was 12.6 mGy × cm(2)/frame and 13.8 mGy × cm(2)/s. Fluoroscopic DAP was 0.8 mGy × cm(2)/pulse and 3.1 mGy × cm(2)/s. Patient reference point air kerma was 17.0 mGy (11.1-28.1) and contrast volume was 70 ml (60-85).
  
  
  CONCLUSIONS
  In conclusion, invasive ECG-gated coronary imaging is feasible in clinical routine and enables patient EDs of approx. 3 % of typical values in invasive cardiology: 0.13 mSv (0.09-0.20).
authors.affiliation: Department of Cardiology, Klinik Fraenkische Schweiz, Feuersteinstr. 2, 91320, Ebermannstadt, Germany, eberhard.kuon@klinik-fraenkische-schweiz.de.
authors.forename: E
authors.initials: E
authors.lastname: Kuon
authors.forename: S B
authors.initials: SB
authors.lastname: Felix
authors.forename: K
authors.initials: K
authors.lastname: Weitmann
authors.forename: I
authors.initials: I
authors.lastname: Büchner
authors.forename: A
authors.initials: A
authors.lastname: Hummel
authors.forename: M
authors.initials: M
authors.lastname: Dörr
authors.forename: T
authors.initials: T
authors.lastname: Reffelmann
authors.forename: A
authors.initials: A
authors.lastname: Riad
authors.forename: M C
authors.initials: MC
authors.lastname: Busch
authors.forename: K
authors.initials: K
authors.lastname: Empen
mesh_terms: D000368:Aged; D055424:Cardiac-Gated Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D017023:Coronary Angiography / Q000295:instrumentation / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control; D011835:Radiation Protection / Q000295:instrumentation / Q000379:methods; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*