In the present study contrast enhanced CT of chelonian kidneys was evaluated. 20 Testudo hermanni from a private owner received non-ionic iodinated contrast media (Imagopaque®) intra venously. These 20 Individuals were divided into three groups: the first group received 1ml contrast media/kg bodyweight (n=7), the second group 2ml/kg bodyweight (n=6) and the third group 3ml/kg bodyweight (n=7). Contrast enhanced studies were repeated three times after plain CT scans. The enhanced images were classified subjectively into good / poor / no enhancement. The images with the best enhancement were chosen for kidney measuring. Additionally the length of the body of the seventh cervical vertebra and the length of the endoplastron were determined. A proportion to the length of the kidneys like in dogs and cats was calculated.
The kidneys of all individuals could be determined on plain and contrast enhanced images. On plain images the kidneys measured 2.3 cm in length, 2.5 cm in width and 1.9 cm height, whereas after contrast application they measured 2.2 cm in length, 2.9 in width and 1.9 cm in height. The mean density of the kidneys was 31.7 HU on plain CT and 80.4 HU after contrast media application. Left and right kidneys enhanced simultaneous and equally. The plain kidneys of male tortoises were denser (34.8 HU) than the kidneys of females (27.1 HU). This proportion changed after contrast media application (mean density males: 74.5 HU, mean density females: 89.2 HU).
The mean length of the seventh cervical vertebra was 1.2 cm. The length of the endoplastron was measured in two different ways. The mean length measured 3.1 cm when determined in a paramedian plain. On reconstructed coronare planes the mean length was 3.2 cm. The data of the seventh cervical vertebra was not chosen for definition of a possible ratio because of systemic inaccuracy. The ratio of the endoplastron length to the kidney length was 1.43, which means that the endoplastron´s length was 1.5 times longer than the length of the kidneys.