Reliability of Evaluation of the Craniocervical Junction by XR, CT and MRI in Patients with Genetic Skeletal Diseases

Background: Craniocervical Junction (CCJ) imaging interpretation in patients with Genetic Skeletal Disorders (GSDs) is challenging due to bone tissue disorganization. CCJ abnormalities and spinal cord compression present potential risks. Purpose: To describe and compare CCJ measurements in patients with GSDs using XR, CT and MRI. Materials and Methods: This cross-sectional observational and analytical study prospectively included 287 participants. Clinical evaluation, spine XR, CCJ dynamic CT, and brain and spinal cord MRI data were recorded. The participants were separated into groups with and without cervical Spinal Cord Injury (cSCI). Three craniometry measurements were performed with each imaging method, and the reliability and reproducibility were analyzed. Results: cSCI was identified in 4.5%. Spinal canal stenosis at C2 (78.8%), a narrowed foramen magnum (12,5%), os odontoideum (5.9%), ventral cervicomedullary encroachment by the odontoid (20.2%), and basilar impression/invagination (12.9%) were associated with an increased chance of cSCI. CT showed the highest accuracy for bone abnormality diagnoses. The cutoff points for the spinal canal to diagnose cSCI were 17.3 mm with XR, 12.9 mm with CT and 10.4 mm with MRI. Conclusion: CT showed good reliability and reproducibility in evaluating the CCJ in GSDs. XR presented more limitations but provided complementary data to MRI.