Vertebral Scale System to Measure Heart Size in Dogs in Thoracic Radiographs

摘要

Radiographs of thoracic cavity are useful as a diagnostic modality to detect heart diseases and have a potential to provide information equivalent to other cardiac diagnostic modalities. Radiographic interpretation can be done by number of ways viz., by gross examination or by using different measurements like cardiothoracic ratio, relationship with inter-costal spaces or vertebral heart score. Cardiothoracic ratio and a specification of 2.5 to 3.5 inter-costal spaces had been introduced in veterinary medicine as an indicator of normal heart size in lateral radiographic views for dogs, but due to some limitations, use of these techniques has been supplanted by another cardiac measurement technique called the vertebral heart score, in which the heart length and width on the thoracic radiograph is compared with the vertebral length. The vertebral heart score may be useful in assessing the change in size of the heart in a patient over time as there is good correlation between the growth of different visceral organs and vertebral body length. Knowledge of inter-breed variation in the thoracic conformation and selection of proper reference value may further enhance the value of vertebral heart score technique in diagnosis of cardiac enlargement in dogs