Evaluation of Intervertebral Disc Space Width Between 10th and 11th Thoracic Vertebrae in Cats Using Radiography and...

It is well known that the T10-T11 intervertebral disc space is usually narrower than the adjacent intervertebral disc spaces in most dogs. However, whether the T10-T11 disc space is narrower than the adjacent disc spaces is not well-established in cats.

To measure the intervertebral disc space width of the T10-T11 disc space and to compare it with that of the adjacent disc spaces using radiography and magnetic resonance imaging (MRI).

In Groups 1 (101 clinically normal cats) and 2 (32 cats without spinal diseases from T8 to T13), dorsal width (DW), central width (CW) and ventral width (VW) of the T8-T13 disc spaces were measured by radiography or MRI. Significant differences of the DW, CW and VW among disc spaces measured by radiography and MRI were evaluated. Intra- and interobserver reliabilities were measured by intraclass correlation coefficient.

In Groups 1 and 2 using radiography, the DW and CW of the T10-T11 disc space were significantly narrower than those of adjacent disc spaces (p < 0.05). The DW of the T8-T12 disc spaces was significantly narrower than that of the T12-T13 disc space in Group 1 using radiography. In Groups 1 and 2 using radiography, the CW and VW of the T8-T11 disc spaces were significantly narrower than those of the T11-T13 disc spaces. In Group 2 using MRI, the DW of the T10-T11 disc space was significantly narrower than that of the T11-T13 disc spaces. The VW of the T8-T11 disc spaces was significantly narrower than that of the T11-T13 disc spaces.

The T10-T11 intervertebral disc space on radiography is statistically narrower than the adjacent intervertebral disc spaces in normal cats. The cranial thoracic intervertebral disc spaces (T8-T11) are usually narrower than the caudal thoracic intervertebral disc spaces (T11-T13) on radiography and MRI.