Interobserver variability of radiographic methods for the evaluation of left atrial size in dogs

Abstract

The objectives of this retrospective, observer agreement study were to (a) test variability of radiographic left atrial dimension (RLAD) and vertebral left atrial size (VLAS) measurements among observers with different levels of expertise in thoracic radiology and cardiology, (b) assess whether one method is better than the other in detecting left atrial enlargement (LAE), and (c) assess the agreement among RLAD, VLAS, and American College of Veterinary Internal Medicine (ACVIM) classes. Seventy‐four dogs (eight healthy and 66 with mitral valve disease) with thoracic radiographs and echocardiography performed on the same day were reviewed. Thirty showed echocardiographic LAE. Left atrial dimension was quantified using RLAD and VLAS by six different operators with three levels of clinical experience in veterinary cardiology/radiology. Vertebral heart score and fourth thoracic vertebra (T4) were also measured. Differences in T4, vertebral heart score (VHS), RLAD, and VLAS measurements were found among six operators and among the three levels of clinical expertise as well as between veterinary cardiology readers and veterinary radiology readers (P < .05). The area under the receiver operating characteristic (AUC) curve for VHS showed good performances for all observers and level and type of expertise; the AUC for RLAD and VLAS was suboptimal only for the radiology student. Our RLAD and VLAS cutoffs (1.9 and 2.43 v, respectively) were better related to qualitative radiographic than quantitative echocardiographic LAE evaluation. Radiographic LA dimension and VLAS showed an increase proportional to the worsening of the ACVIM class. In conclusion, these results allow us to affirm that RLAD and VLAS are reproducible measurements for detecting LAE. Better performances are associated with clinical expertise and background.

Vertebral heart size and vertebral left atrial size reference ranges in healthy Maltese dogs

“…For the intraobserver measurement, both VHS and VLAS exhibited an almost perfect agreement while for the interobserver measurement, VHS had an almost perfect agreement while VLAS exhibited a substantial agreement. These results were similar to previous studies assessing inter-and intraobserver measurements for these methods 3,25,26 and supported the idea that both VHS and VLAS are reliable cardiac measurements in Maltese dogs. The lower inter-observer agreement for VLAS compared to the traditional VHS could be a result of the lesser experience of the observers for this method due to its' recent development.…”

“…[20][21][22][23][24] Also, previous studies have shown good intraand interobserver agreements for these measurements, supporting their application for clinical patients. 3,4,25,26 To date, limited data exist regarding the variability of VLAS among breeds. A recent study proposed the normal reference ranges of both VHS and VLAS for healthy Chihuahua dogs revealing different values compared to the initial study.…”

Breed‐specific vertebral heart score, vertebral left atrial size, and radiographic left atrial dimension in Cavalier King Charles Spaniels: Reference interval study

“…They were blinded to echocardiographic findings. The assessment of the interobserver variability of VHS, VLAS, M‐VLAS, and RLAD by multiple observers was not the intent of the study and was previously evaluated 23 . The radiographic examination included right lateral (RL), left lateral (LL), and dorso‐ventral (DV) views.…”

“…Dogs with cardio‐structural heart diseases and cardiac chamber enlargement identified on echocardiogram were excluded from the study, as well as dogs aged <12 months because of the possible influence of young age and skeletal immaturity on the radiographic vertebral‐based measurements. Thoracic radiographs that revealed an overt malposition of the patient (as the considerable rotation, the movement due to excessive breathing for tachypnea or the brachial muscles superimposition on the cranial aspect of the thorax) or the presence of thoracic vertebral abnormalities (eg, hemivertebrae) were not included in the study 23,24 . All decisions for dog inclusion or exclusion were made by two veterinarians with more than fifteen years of clinical experience in veterinary radiology (D.Z.)…”

“…Thoracic radiographs that revealed an overt malposition of the patient (as the considerable rotation, the movement due to excessive breathing for tachypnea or the brachial muscles superimposition on the cranial aspect of the thorax) or the presence of thoracic vertebral abnormalities (eg, hemivertebrae) were not included in the study. 23 , 24 All decisions for dog inclusion or exclusion were made by two veterinarians with more than fifteen years of clinical experience in veterinary radiology (D.Z.) and veterinary cardiology (C.L.…”