Measurement of normal reference values of spinal canal diameter andal reference values of spinal canal diameter and space available for cord (SAC) at mid sagittal level in cervical spine (C3 to C7) in adult East Indian population by MRI

Abstract

Background: Assessment of cervical spinal stenosis, which is not very uncommon presentation among adult age group, is necessary for planning of the management protocol, especially regarding surgical intervention, if necessary. Specific measurements used for assessing spinal canal stenosis, the spinal canal diameter and space available for cord (SAC) at mid sagittal level are considered  to be very important ones. Materials & Methods: To determine the normal range of the absolute values of these two parameters in the local population and their importance in predicting cervical canal stenosis, we selected 100 asymptomatic adult subjects of each of both sexes and 50 symptomatic subjects of each of both sexes. The parameters used in this study for assessment of cervical spinal canal stenosis were mid sagittal spinal canal diameter and the space available for the cord (SAC), which was measured using T2 weighted axial and sagittal MRI cuts at the respective vertebral level.Results: In our study, we analyzed 100 asymptomatic subjects by MRI study (T2 weighted sagittal and axial images) for determination of normal  reference values of canal diameter and space available for cord in C3 to C7 vertebral body level. The values of canal diameter (mean +/- 2SD) in different levels were 12.0±3.3mm (C3); 12.0±2.32mm (C4); 12.0±2.32mm (C5); 12.0±2.3mm (C6); 12.6±2.62mm (C7) and the corresponding space available for cord values were 5.0±2.76mm (C3); 5.1±1.92mm (C4); 5.3±2.14mm (C5); 5.6±2.08mm (C6); 6.3±2.54mm (C7) levels.Conclusion: It is well recognized that mid sagittal spinal canal diameter and space available for the cord (SAC) in cervical vertebrae (C3 to C7) varies considerably in normal adult population of both the sexes and decrease in them will result in cervical stenosis symptoms. Knowledge of normal reference values of these two parameters in Indian population will be helpful for concerned researchers and the normal acceptable range of values will be very helpful for the clinicians to predict spinal canal stenosis and to decide for the necessity of surgical intervention.