Assessment of the value of the vertebral heart scale in the radiographic diagnosis of cardiac disease in dogs

In order to assess the influence of the vertebral heart scale (VHS) on the accuracy of the radiographic diagnosis of cardiac disease, thoracic radiogr aphs of 50 dogs with proven cardiac disease, 26 with other thoracic disease s, and so with no clinical signs of cardiovascular or respiratory disease w ere mixed and examined by three independent, blinded observers chosen to re present a range of radiographic abilities. They first examined all the radi ographs without making measurements of VHS and made a diagnosis. They then re-examined the radiographs. and measured VHS on both lateral and dorsovent ral or ventrodorsal radiographs before again recording a diagnosis without reference to their original diagnoses. For all the observers, the dogs with cardiac disease had a higher mean VHS than the normal dogs. A VHS over 10- 7 on the lateral radiograph was a moderately accurate sign of cardiac disea se. The observers' accuracy of diagnosis did not change significantly as a result of using VHS as an adjunct to a subjective assessment of the radiogr aphs.