Influence of the Head Neck Position on Imaging Measurements Used to Assess the Craniovertebral Junction in Small Breed Dogs: A Cadaveric Study

Abstract

Objective The study aimed to determine the influence of head neck position on imaging measurements used to assess the craniovertebral junction (CVJ) and to recommend the most appropriate position for the evaluation of the CVJ.

Study Design A cross-sectional sample of adult dogs' cadavers was subjected to a computed tomography scan of the cranium and the cranial cervical region in three standardized head positions. Imaging measurements often used to assess the CVJ were measured. The influence of the head neck position, breed, weight and gender on imaging measurements was tested using repeated measures analysis of variance.

Results Twenty-eight cadavers of small breed dogs were enrolled in the study. All cadavers examined had occipital dysplasia. All transarticular imaging measurements were dependent on the head neck position. In addition, the breed, weight and gender had an influence on several measurements.

Conclusion We recommend a standardized head neck position of 50 degrees flexion if quantitative imaging measurements of the CVJ are used to diagnose pathologies in this region. Future studies should focus on the definition of cut-off values for quantitative imaging measurements of the CVJ to differentiate between healthy and diseased small breed dogs. Regarding atlantoaxial instability, a combination of six parameters (C1-C2 angle, C1-C2 overlap, atlantoaxial distance, dens-to-axis length ratio, ventral compression index and clivus canal angle) is promising for its diagnosis.

Keywords

craniovertebral junction - head neck position - computed tomography - magnetic resonance imaging - small breed dogs

Authors' Contributions

B.P. and C.P. contributed to conception of the study, study design and acquisition of the data, data analysis and interpretation. F.F. contributed to the collection of the samples, conception of the study and study design. B.V. contributed to the study design, data analysis and interpretation. A.B. and A.M. contributed to the data analysis. All authors drafted, revised and approved the submitted manuscript.

Publication History

Received: 12 August 2020

Accepted: 22 January 2021

Article published online:
12 May 2021

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