Evaluation of Cranio-Cervical Junction on Multidetector Computed Tomography

Abstract

Background and purpose: The craniovertebral junction area refers to the osseous structures consisting of the occipital bone that surrounds the foramen magnum, the atlas, and the axis vertebrae. There is sparse literature about the morphometric measurement of craniovertebral junction region. We aimed to derive a range of various measurements in craniovertebral junction area. Materials and methods: This retrospective cross-sectional study was performed at the Department of Radiology and Imaging, Tribhuvan University Teaching Hospital, Maharajgunj, Kathmandu, Nepal. Data were collected over the period of January to April 2021 with total of 153 patients who underwent CT scan of C- spine, Neck and Carotid angiography without having any pathological findings related to craniocervical junction. The measurement was done at mid sagittal section in MPR. Various parameters like patient’s age, gender, Basion-Axial interval (BAI), Dens Height (DH), Basion Dens interval (BDI), Right and Left Atlanto-axial interval (RLAOI), Anterior and Posterior Atlantodental interval (A\PADI), Power Ratio (PR), McRae line (MR), Redlund-Jonhel Distance (RLD) and modified Ranawat line (mRWD) were measured. Results: Among 153 patients studied, 87 [57.9%] of them were males while 66 [43.1%] were females. Mean age was 48.61±18.690 years with range from 18 to 92 years. The measurement of craniocervical junction in computed tomography revealed the mean BAI of 0.561±0.226 cm, DH of 3.477±0.263 cm, BDI of 0.474±0.167 cm and RAOI of 0.139±0.233 cm. Similarly, the mean LAOI was 0.139±0.238 cm, mean AADI was 0.149±0.422 cm, and PADI was 1.767±0.194 cm. The mean PR was 0.699±0.083 cm. While measuring the distance from the tip of the odontoid to McRae’s line, mean was 0.412±0.161cm. Mean Redlund Johnell distance was calculated to be 3.484±0.438 cm and mRWD was measured to be 2.688±0.215 cm. Conclusion: Normal morphometric measurements of craniovertebral junction can be useful for evaluating abnormalities of the craniovertebral junction which can potentially improve the diagnostic criteria of most abnormalities. Key words: CT Scan, Craniocervical junction (CVJ), Distance