Interobserver agreement in interpretation of radiographic pulmonary changes in dogs in relation to radiology training

Interpretation of pulmonary radiographs is one of the most difficult aspects of radiology and interobserver variability is high. The aim of this study was to assess variations in interpretation of pulmonary pathology amongst Brazilian veterinarians with different levels of training and experience, using the interpretation by American board-certified radiologists as a reference. We identified areas where interpretation is particularly challenging. Sixty digital canine thoracic radiographic examinations were interpreted by four groups of three Brazilian observers, each group being defined by different levels of training and experience. The radiographic findings of the 4 groups of observers in the study were compared to a reference interpretation established from the findings of three ACVR board-certified radiologists. The degree of discrepancy for each list between each group and the reference interpretation was assessed according to a three-level scoring system: no discrepancy, minor discrepancy, or major discrepancy. Data was analyzed using a Kappa and Cochran-Mantel-Haenszel tests. Brazilian veterinarians with the most training and experience showed the least interobserver variation and best performance when compared to the reference interpretation, followed by those with practical training, but with little work experience in professional practice. The radiographic patterns that were associated with the highest interobserver variability were the vascular, unstructured interstitial and bronchial patterns. Interobserver major discrepancies occurred in all groups, but is more evident in groups with the least training (44.4%) and the general practitioners (26.7%) group. It can be concluded that training positively influences the accuracy of radiographic interpretation and is recommended to reduce erroneous diagnoses.