title: Applicability of ECG-gated multislice helical ct to patients with atrial fibrillation.
abstract: BACKGROUND
  Multislice computed tomography coronary angiography (CTCA) is reconstructed by ECG gating and consequently it is difficult to obtain coronary artery images from patients with arrhythmias, such as atrial fibrillation (AF), by the conventional method.
  
  
  RESULTS
  Eleven patients with AF (9 males, 2 females; mean age: 62.5 years) underwent CTCA using a slice thickness of 0.5 mm, gantry rotation of 0.4 or 0.5 s/rot and pitch of 3.2-4.0. A segmented reconstruction method was used to construct CTCA images at the conventional relative 70-75% (mid-diastolic phase) and 30-35% (end-systolic phase) of the R-R interval and furthermore, the absolute mid-diastolic phase and end-systolic phase from the R wave. Three investigators, who were unaware of the coronary angiography results, independently evaluated the curved multiplanar reconstruction (MPR) images. In both the relative and absolute phase reconstruction, there were motion artifacts in the mid-diastolic than in the end-systolic phase. The absolute phase images had less motion artifacts than the conventional relative phase images. Optimal curved MPR images were obtained in the absolute end-systolic phase. The quality and motion artifacts of those optimal images from AF patients were similar to those from patients in sinus rhythm.
  
  
  CONCLUSIONS
  The absolute end-systolic phase is the best time to get optimal CTCA images in AF patients.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Fujita Health University, School of Medicine, Toyoake, Japan. takahisa@fujita-hu.ac.jp
authors.forename: Takahisa
authors.initials: T
authors.lastname: Sato
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Anno
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Hiroto
authors.initials: H
authors.lastname: Harigaya
authors.forename: Kaori
authors.initials: K
authors.lastname: Inoue
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kakizawa
authors.forename: Keita
authors.initials: K
authors.lastname: Ohshima
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Sarai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hishida
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Katada
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kanou
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging*; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008875:Middle Aged; D036542:Tomography, Spiral Computed / Q000295:instrumentation / Q000379:methods