A Study to Find Normal Dimensions of Spinal Cord on MRI in Indian Population

Abstract

Background: Knowledge of normal measurements of the spinal cord is essential in diagnosing and interpreting various spinal disorders. There is sparse data on normal morphometry of spinal cord in Indian population. Aims and objectives: To obtain dimensions of the human spinal cord, at various vertebral levels in normal population on MRI. Subjects and Methods: A cross sectional observational study was done on 60 healthy subjects aged between 20 to 40 years who underwent MRI in a tertiary care centre from December 2017 to Dec 2018. Dimensions of the multiple segments of human spinal cord were measured in Antero-posterior and transverse diameters at each level by high resolution T2-weighted images by 1.5 T Philips MR System Achieva. Results: Mean age of subjects was 28 years. In the cervical segment, the AP diameter of the spinal cord was greatest at C1 (7.74 mm in males, 6.63 mm in females) and lowest at C7. The Transverse diameter decreased from C1 to C2 level, and then increased from C2 to C5, with C5 (12.84 mm in males and 11.55 mm in females) being the maximum enlarged segment and then decreased towards C7. In the upper thoracic cord, the AP diameter and transverse diameter was maximum at D1 and decreased gradually from D1 to D6. In the lower thoracic cord, the AP diameter and transverse diameter was maximum at D12. Conclusion: Spinal cord dimensions vary at different segments and also between males and females. Hence, there is a need to establish normal reference values of spinal cord diameters at various levels.