title: Prospective ECG-gated coronary 320-MDCT angiography with absolute acquisition delay strategy for patients with persistent atrial fibrillation.
abstract: OBJECTIVE
  The purpose of this study was to evaluate image quality and radiation dose when patients with atrial fibrillation undergo coronary CT angiography (CTA) using prospectively ECG-gated 320-MDCT technology with an absolute-delay strategy.
  
  
  METHODS
  A cohort of 75 consecutive patients (60 men and 15 women; age (± SD), 71 ± 10 years) who underwent prospectively ECG-gated coronary CTA using a 320-MDCT scanner during atrial fibrillation was matched with 75 control patients imaged in sinus rhythm. All coronary CTA for the atrial fibrillation cohort used absolute-delay strategy. Subjective image quality score and the dose-length product (DLP) were compared between the two cohorts and, for the atrial fibrillation cohort, among those patients imaged over a different number of heartbeats. The accuracy of stenosis detection was evaluated in 17 studies of the atrial fibrillation cohort using catheter angiography as a reference standard.
  
  
  RESULTS
  For those patients imaged in atrial fibrillation, one- and two-beat acquisitions were performed in 26.7% (n = 20) and 40% (n = 30) of patients, respectively. There was no significant difference in image quality between the atrial fibrillation (2.9 ± 0.4) and sinus rhythm (2.9 ± 0.3) cohorts, nor was there a difference in image quality with respect to the number of heartbeats used in the acquisition. The atrial fibrillation cohort had an 80% higher DLP (680 ± 470 vs 372 ± 236 mGy × cm, p < 0.0001). The patient-based sensitivity and negative predictive value for stenosis detection were both 100%.
  
  
  CONCLUSIONS
  Using an absolute-delay strategy, two thirds of patients who underwent prospectively ECG-gated coronary CTA using a 320-MDCT scanner were imaged within two heartbeats or fewer. Compared with patients imaged in sinus rhythm, the image quality was comparative and the radiation dose was 1.8-fold higher.
authors.affiliation: 1 Department of Cardiology, Takase Clinic, 885-2 Minami-orui, Takasaki 370-0036, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Kanako K
authors.initials: KK
authors.lastname: Kumamaru
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsutani
authors.forename: Tomonari
authors.initials: T
authors.lastname: Sano
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takase
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Rybicki
mesh_terms: D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging*; D055424:Cardiac-Gated Imaging Techniques; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007479:Iopamidol; D008297:Male; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007479:Iopamidol