Interobserver agreement of computed tomography in detecting calcified intervertebral discs in comparison with radiography in a population of 13 healthy British Dachshund dogs

BACKGROUND: The aims of this retrospective study were to estimate interobserver agreement in detecting disc calcification with computed tomography (CT) and to compare the number of calcified intervertebral discs identified on CT and radiography in healthy British Dachshund dogs that underwent a screening programme. The current screening programme uses radiography to identify calcified intervertebral discs. METHODS: Healthy Dachshunds aged between 2 and 5 years presenting for spinal radiography and CT as part of a disc scoring scheme were included. The spinal radiographs were scored by an independent assessor as per the screening programme protocol. The CT images were blinded and reviewed by three different observers of differing levels of experience. The number of discs identified as being calcified was then compared between imaging modalities and between observers. RESULTS: Thirteen dogs were included. Overall, 146 calcified discs were identified by CT compared with 42 by radiography. There was an almost perfect agreement among the three observers identifying calcified discs with CT images (k = 0.92). There was a significant difference between the radiography scores and CT scores. CONCLUSIONS: This study demonstrated a significant difference in the number of calcified intervertebral discs identified in the vertebral column of a small population of healthy Dachshunds between CT and radiography. Given the high agreement between the observers with CT, this may be a reliable method for assessing disc calcification in Dachshund dogs and could be a good candidate for future breeding schemes.