title: Common two-dimensional echocardiographic estimates of aortic linear dimensions are interchangeable.
abstract: OBJECTIVE
  To compare two echocardiographic methods of measuring aortic diameter in short-axis projections.
  
  
  METHODS
  Right-parasternal short-axis 2-dimensional projections of the left atrium and aorta were obtained from dogs and cats undergoing routine cardiac evaluation. Two investigators measured the aortic valve linear dimension using 2 methods: along the commissure between the non-coronary and right-coronary cusps and along the commissure between the non-coronary and left-coronary cusps. Inter-observer and intra-observer variability and agreement were assessed by comparing blinded measurements with each method by 4 trained observers on a standardized set of images. Measurements were compared for agreement using the limits of agreement analysis. Variability between observers was compared by examining residuals and intraclass correlation.
  
  
  RESULTS
  274 canine and 100 feline aortic valve images were measured in the first part of the study. One observer demonstrated slight proportional bias, while the other observer showed more variability (less agreement). When results were pooled for both investigators, no bias was identified, and 95% limits of agreement were ±10% of the mean measurement for both species. In the second part of the study, 106 images were measured. Intraobserver variability was <4% for all observers. Inter-observer agreement was very high. Individual bias was identified in some observers, but was considered clinically inconsequential. Normalized differences between the 2 methods of measurement were below ±15% of the measured value for all observers.
  
  
  CONCLUSIONS
  Our results show sufficient agreement between two common methods used to measure aortic linear dimensions to suggest that these methods are interchangeable.
authors: Central Veterinary Clinic, Sofia, Bulgaria.
authors: Ranko
authors: R
authors: Georgiev
authors: Mark
authors: M
authors: Rishniw
authors: Ingrid
authors: I
authors: Ljungvall
authors: Nuala
authors: N
authors: Summerfield
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000033:anatomy & histology*; D002415:Cats / Q000033:anatomy & histology*; D004285:Dogs / Q000033:anatomy & histology*; D004452:Echocardiography / Q000706:statistics & numerical data / Q000662:veterinary*; D005260:Female; D008297:Male; D015588:Observer Variation