Determination of cutoff values on computed tomography and magnetic resonance images for the diagnosis of atlantoaxial instability in small‐breed dogs

• DOI: 10.1111/vsu.13799
• Publication Date: 2022-03-16T07:57:56Z
• Authors: Bastien Planchamp; Franck Forterre; Beatriz Vidondo; Angel M. Hernande...; Ioannis N. Plessas; Martin J. Schmidt; Maja A. Waschk; Christina Precht
• Keywords: Cut-off; Atlantoaxial instability

Abstract Objective To determine cutoff values for the diagnosis of atlantoaxial instability (AAI) based on cross‐sectional imaging in small‐breed dogs. Study design Retrospective multicenter study. Sample population Client‐owned dogs ( n = 123) and 28 cadavers. Methods Dogs were assigned to three groups: a control group, “potentially unstable” an AAI‐affected according findings clinical signs. The ventral compression index (VCI), cranial translation ratio (CTR), C1‐C2 overlap, angle, distance, basion‐dens interval, dens‐to‐axis length (DALR), power ratio, clivus canal angles measured CT or T2‐weighted magnetic resonance (MR) images. Receiver operating characteristic (ROC) analysis was performed define flexed (≥25°) extended (<25°) head positions. Results Cutoff VCI ≥0.16 ≥0.2 positions diagnostic AAI (sensitivity 100% 100%, specificity 94.54% 96.67%, respectively). other measurements defined with lower sensitivity (75%‐96%) (70%‐97%). A combination did not increase compared as single measurement. Conclusion several established good specificity. VCI, between dorsal atlantodental had highest both Clinical significance use allows objective decision surgical intervention, however, should remain findings.