Reproducibility of semi-automatic system of radiographic measurement of the cardiac silhouette of the dog

Abstract

It's presented a proposal for a study of the reproducibility potential of semi-automatic system of radiographic measurement. To do so will be measured, by means of a computer software, the Vertebral Heart Size (VHS), the angle between the sternum and the major axis of the heart (angle) and normalized cardiac area (NCA) in radiographic images of clinically normal dogs with mitral insufficiency. Given the subjectivity of the analysis of the cardiac silhouette by different observers, it is believed that even with a semi-automatic system that assessment could be affected by the previous experience of the observer in the field of radiology. Therefore, It is necessary a study to evaluate whether this method is really affected by the experience of the observer or not. For this, will be reviewed 57 images of chest radiographs of dogs presented to the Veterinary Hospital (HOVET), Faculty of Veterinary Medicine and Zootechny of the University of São Paulo (USP-FMVZ) between the years 2009 and 2011. The animals will be divided into two groups: (I) normal cardiopulmonary structures (n = 18) and (II) with heart disease (n = 39) confirmed by echocardiography as mitral insufficiency. The images are analyzed by two groups of observers with different levels of experience in radiology: (A) with experience in Diagnostic Imaging (n = 2) and (B) without experience in Diagnostic Imaging (n = 2). The conclusion of this study will assess the intra-observer and inter-observer concordance of the semi-automatic system of measurement of the cardiac silhouette considering different degrees of experience of the evaluators.