Radiographic abnormalities in cats with feline bronchial disease and intra- and interobserver variability in radiographic interpretation: 40 cases (1999–2006)

Objective—To determine prevalence of various radiographic signs in cats with feline bronchial disease (FBD) and evaluate intra- and interobserver variability in radiographic interpretation for examiners with variable degrees of experience in radiographic interpretation. Design—Retrospective case series. Animals—40 cats with FBD and 40 control cats without thoracic disease. Procedures—Radiographic abnormalities in cats with FBD were scored by consensus of 2 radiologists. Radiographs of control cats and cats with FBD were examined twice by 5 other individuals, and diagnostic accuracy and observer agreement were assessed. Results—In cats with FBD, the most common radiographic signs were bronchial (n = 37) and unstructured interstitial (30) lung patterns, lung hyperinflation (31) and hyperlucency (21), aerophagia (19), and lung soft tissue opacities (11). Ratios of lung inflation on ventrodorsal views were significantly higher in cats with FBD. For the 5 examiners, sensitivity ranged from 71% to 89% and specificity ranged from 43% to 74%. Intraobserver agreement was good (N = 0.47 to 0.60), but the agreement between examiners was only poor to good (N = 0.22 to 0.70). For most examiners, significant associations were found between examiner diagnosis (correct vs incorrect), level of examiner certainty, and bronchial pattern severity. Conclusions and Clinical Relevance—Findings suggested that several radiographic abnormalities can commonly be seen in cats with FBD but highlighted the limitations of thoracic radiography. Examiner diagnosis and level of confidence were significantly associated with severity of a bronchial pattern.