title: Diagnostic performance of two types of low radiation exposure protocol for prospective ECG-triggering multidetector computed tomography angiography in assessment of coronary artery bypass graft.
abstract: BACKGROUND
  Multidetector computed tomography (MDCT) is useful in evaluation of coronary artery bypass graft (CABG). However, radiation exposure is a reason for concern. We compared diagnostic performance and effective dose of a new dedicated post-processing reconstruction algorithm with BMI-adapted scanning protocol (MDCT-XTe) vs. standard prospective ECG-triggering protocol (MDCT-XT) and retrospective ECG-triggering (MDCT-Helical), compared to invasive coronary angiography (ICA), in the assessment of grafts and nongrafted or distal runoff coronary arteries.
  
  
  METHODS
  One hundred and nineteen patients with 277 grafts were randomized to Group 1 based on BMI-adapted scanning protocol with prospective ECG-triggering (40 patients), Group 2 with prospective ECG-triggering (39 patients) and Group 3 (40 patients) with retrospective ECG-triggering. Data were acquired using 64-slice MDCT.
  
  
  RESULTS
  MDCT correctly assessed the patency of all CABG in 3 groups. After comparison with ICA, MDCT was able to correctly detect the occlusion or stenosis of CABG in all groups, with the exception of one case of Group 3. In Group 3 sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CABG evaluation were 100%, 98.4%, 96.7%, 100% and 98.9%, respectively. In Groups 1 and 2 the diagnostic accuracy of CABG evaluation was 100%. Effective radiation dose was 3.5±1.4mSv in Group 1 vs. 7.4±2.6mSv in Group 2 vs. 27.8±9.4mSv in Group 3.
  
  
  CONCLUSIONS
  Our results indicated that MDCT-XTe and MDCT-XT have a diagnostic performance in the evaluation of CABG similar to MDCT-Helical, with a significant reduction of radiation exposure, specially for MDCT-XTe.
authors.affiliation: Department of Cardiovascular Sciences, University of Milan, Milan, Italy. daniele.andreini@ccfm.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Andreini
authors.forename: Gianluca
authors.initials: G
authors.lastname: Pontone
authors.forename: Saima
authors.initials: S
authors.lastname: Mushtaq
authors.forename: Andrea
authors.initials: A
authors.lastname: Annoni
authors.forename: Alberto
authors.initials: A
authors.lastname: Formenti
authors.forename: Erika
authors.initials: E
authors.lastname: Bertella
authors.forename: Alessandro
authors.initials: A
authors.lastname: Parolari
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Agostoni
authors.forename: Antonio
authors.initials: A
authors.lastname: Bartorelli
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ballerini
authors.forename: Cesare
authors.initials: C
authors.lastname: Fiorentini
authors.forename: Mauro
authors.initials: M
authors.lastname: Pepi
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D004562:Electrocardiography / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods / Q000592:standards*; D011446:Prospective Studies; D011829:Radiation Dosage