New methods to differentiate cardiac and non-cardiac disease cats from thoracic radiographs

Abstract

The objective of this study was to distinguish between cats with cardiac disease and non-cardiac disease by using parameters obtained from thoracic radiographs. This study was performed in 49 cats with a mean age of 7.7±4.79 years. Weight, sex and breed of all cats were randomly chosen. Echocardiography was used as a gold standard to diagnose cardiac disease and separate the cats into two groups, cardiac disease (n=31) and non-cardiac disease (n=18). Five parameters were measured from the right lateral radiographs including 1) the cardiac length (L), 2) the cardiac width (W), 3) the width of the caudal vena cava (CVC), 4) the height of the spinous process of the fourth thoracic vertebrae (sT4), and 5) the length of the fourth sternal thoracic bone (S4). Ten formulae were designed from the five parameters. Five of these formulae produced an outcome showing a significant difference between the two groups (p<0.05). These formulae included L•W, L•W/sT4, L•W/S4, SUMLW/S4, and SUMLW•CVC. This study recommends the formulae L•W (cut-off >16.45 cm2; sensitivity of 82.2% and specificity of 67%) and L•W/S4 (cut-off >12.85 cm; sensitivity of 81.7% and specificity of 66.9%). In conclusion, these two new formulae can be used as a screening tool for distinguishing cats with cardiac and non-cardiac diseases.