Morphological study of neurocentral synchondrosis in fetal spines

Abstract

Objective To apply imaging examinations for surveying the morphological characteristics of neurocentral synchondrosis (NCS) in fetal spine so as to deduce the function of NCS in the growth of vertebra and vertebral pedicle in normal spines. Methods A total of 15 fetal samples (23 w-33 w) without congenital spinal deformity were collected from October 2012 to December 2013. There were 8 males and 7 females with an average gestational age of 28+ 6 weeks. And informed consent form was signed. Based upon fetal age, the fetuses were divided into two groups of 7 samples (24 w) and 8 samples with an average gestational age of 32 w. All fetuses were visualized by magnetic resonance imaging (MRI) (T1-L5 vertebra) and full-spine spiral computed tomography (CT) + three-dimensional (3D) reconstruction. The above methods could observe the 3D morphology of NCS. Then the relevant parameters were measured by dicom image processing software. And the mean value of each group was calculated and line plotted by Origin software. All parameters of both sides were analyzed by paired t-test. And the test standard was set at P=0.05. Results As a pair of triangular structure with a wide exterior and a narrow interior in sagittal plane on T2 MRI image, NCS surrounds both vertebral body and posterior arch and inter-connected in anterior aspects. And it is reconstructed by two parallel lines perpendicular to vertebrae in sagittal plane on full-spine spiral CT + 3D reconstruction images. The mean parameters of two groups were calculated and the corresponding lines plotted. It showed that α angle increased faster than that of the second one. The others parameters of the second fetal group were bigger than those of the first one. The mean α angles of left and right sides were 60.827°±2.794° and 60.882°±2.840° for the first group and 58.878°±4.194 and 58.749±4.334 for the second group respectively. And the bilateral length-width ratios were 1.452±0.096 and 1.435±0.124 for the first group and 1.680±0.147 and 1.678±0.142 for the second group. The parameters of two groups were compared by paired t-test and the differences of two sides of two group were significant (P 0.05). Conclusions The position of NCS shifts constantly. It accounts for a bigger volume of vertebral body in fetal spines. And its role for the growth of spine is larger than that in infants and young children. Key words: Vertebral column; Fetus; Cartilage