Morphometric (MRI and sonography) study of the human spinal cord in prenatal and postnatal life (from birth to 20 years)

Abstract

Introduction The assessment of the position of the conus medullaris is very important to perform lumbar puncture and surgical procedures. There are some reports about the relationships between the clinical manifestations and the spine morphology or spinal cord morphology in patients with myelopathy. It has also been reported that there are variations in the cross-sectional area of the cervical segments of the spinal cord. Aim The aim of the present study was to compare the levels of conus to measure the diameters of the cervical spinal cord segments. Participants and methods In the prenatal group, sonographic evaluation of the conus medullaris and the conus distance were carried out. In the postnatal group, the T2-weighted MRI was used to record the level of conus medullaris. In addition, the transverse and anteroposterior diameter of the cervical spinal cord and cross-sectional area from C2 to T1 at the level of each intervertebral disk were investigated. Results In the prenatal group, the mean of conus distance was 32.38 ΁ 12.13 mm. The level of the tip of the conus medullaris in the postnatal group showed almost distribution from the T12 to L2-L3 disk. The peak of the distribution of the conus height was at the level of disk between T12 and L1. The anteroposterior diameter decreased linearly from C2 to T1.The transverse diameter and the cross-sectional area were largest at the level of C4-C5, and decreased progressively to segment T1. There was no statistically significant difference in relation to sex. Conclusion Linear regression analysis showed a significant correlation between the conus distance and gestational age and femur length. The ascent of conus medullaris seems to occur early in postnatal life. The transverse diameter and the cross-sectional area were largest at the level of C4-C5, whereas the anteroposterior diameter decreased from C2 to T1.There was no significant correlation between cervical diameters and sex.