Objective: To measure cranio-vertebral parameters in asymptomatic individual in CT head and to study the deviation from the normal range in Indian population with their MRI correlation.

Materials & Methods: The present study was carried out as a prospective cross-sectional comparative study at Department of Radiodiagnosis, Gandhi Medical College & associated Hamidia Hospital Bhopal during the study period of one year. Data collection was done & information was recorded on a proforma. The patients then underwent NCCT head. Parameters such as Welcher basalangle, Clivus canal angle, Boogards angle, Foramen magnum (Anteroposteriorand transverse diameter), Length of clivus, Distance between tip of dens & Mcrae’sline, clivus canal line tangential/transecting the dens and cord abnormality were assessed. Any deviation from the normal values were noted normal being the mean value under one standard deviation of the population assessed. The subjects with abnormal parameters underwent MRI which were then correlated with the CT findings.

Results: This study was conducted on a total of 3822 participants of them, 42 had CVJ anomaly on CT scan. Among the patients with incidentally detected CVJ anomalies, majority (69%) of patients reported BI followed by AOA (42.9%), PTB (21.4%), OSD (4.8%) and OT (2.4%). Combination of anomalies are also found. Among the patients with abnormal CVJ parameters, 11.9% of subjects reported presence of cord signal in MRI, 69% of subjects found clivus canal line transecting dens and remaining 31% found tangential to dens in both MRI and CT scan.

Conclusions: Basilar invagination (BI) was the most common CVJ anomaly found in our study. The most common combination were (BI)+ (AOA). Comparison of CT and MRI findings with respect to Dens in relation to McRae’s line and association of CT and MRI findings with respect to Wackenheims clivus canal line (TTT) was found significant. Spinal cord signals could be pickedup by MRI.