title: Comparison of determinations of left atrial volume by the biplane area-length and Simpson's methods using 64-slice computed tomography.
abstract: OBJECTIVE
  There is increasing evidence that left atrial (LA) size is an important predictor of adverse cardiovascular outcomes such as atrial fibrillation, stroke, and congestive heart failure. The aim of this study was to determine whether there is a difference in results of quantification of LA volume by the area-length and Simpson's methods using multislice computed tomography (MSCT).
  
  
  RESULTS
  The study population consisted of 51 patients with sinus rhythm (sinus group) and 20 patients with atrial fibrillation (af group) clinically indicated for MSCT angiography for evaluation of coronary arteries. Maximum LA volume, obtained at end-systole from the phase immediately preceding mitral valve opening, was measured using the area-length and Simpson's methods. In the sinus group, the mean LA volumes, indexed to body surface area, were 48.4+/-17.9 ml/m(2) with the area-length method and 48.3+/-17.0 ml/m(2) with the Simpson's method. In the af group, the mean indexed LA volumes with the area-length method and the Simposon's method were 91.5+/-47.5 ml/m(2) and 90.3+/-45.9 ml/m(2), respectively. LA volumes calculated by the area-length method exhibited a strong linear relationship and agreement with those calculated using Simpson's method in both the groups (sinus group: r=0.99, P<0.0001, af group: r=0.99, P<0.0001).
  
  
  CONCLUSIONS
  The area-length method is a simple and reproducible means of assessment of LA volume. Standardization of LA volume assessment using MSCT is important for serial follow-up and meaningful communication of results of testing among institutions and physicians.
authors.affiliation: Department of Internal Medicine, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takagi
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ehara
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Okuyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shirai
authors.forename: Hajime
authors.initials: H
authors.lastname: Yamashita
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugioka
authors.forename: Hitoe
authors.initials: H
authors.lastname: Kitamura
authors.forename: Keiji
authors.initials: K
authors.lastname: Ujino
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hozumi
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshiyama
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging; D003327:Coronary Disease / Q000000981:diagnostic imaging; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*