Determination of Vertebral Index in Thoracic Roentgenographs of the Rabbit (Oryctolagus cuniculus)

Aim: There are numerous thoracic cage malformations that variably affect the contour and volume of the thorax in both humans and animals. Common thoracic congenital disorders are pectus deformities, and objective measures delineating the limits of normal and deformation are yet to be defined in the New Zealand White (NZW) rabbit. This research was aimed at establishing values of vertebral index (VI) of clinically normal NZW rabbit, for reference purposes.

Materials and Methods: Ten healthy NZW rabbits were acquired for this investigation. A right lateral (RtL) thoracic roentgenograph of each research animal was made. The sternovertebral distance and diameter of the tenth thoracic vertebra (T10) were evaluated in centimetres in each of the radiographs. The quotient of the vertebral diameter and sum of the same vertebral diameter and the sternovertebral distance was then obtained from each experimental radiograph as the VI for the rabbit concerned.

Results: Mean plus or minus standard error of mean (M±SEM) VI was 0.1±0.01, and the difference between male and female VIs was statistically insignificant.

Conclusion: VI is clinically, objectively, and easily applicable in radiographic investigation of the thoracic shape and depth.