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.

The vertebral column is a part of the axial skeleton of man which has to perform particular tasks. The objective of the study was to quantitatively measure the spinal cord, regionally and segmentally so as to gather basic morphometric data in healthy population. Material and Methods: A total of 60 healthy participants aged between 20-60 years were included in this cross-sectional study. All of them underwent MRI scan of their healthy spine after a thorough clinical examination at HSK hospital from December 2016 to May 2018. Results: The mean age of the participants was 28 years with equal number of males and females. In the cervical segment, the AP diameter 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. The AP spinal canal diameter decreased from C1 to C5 and then gradually increased from C5 to 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: While assessing the spinal cord size, a single number measurement may not be enough rather each level should be compared with a set of normal values specific for that level.