CT Morphometric Analysis of Ossification Centres in the Fetal Th12 Vertebra.

OBJECTIVES: The present study aimed to determine the growth dynamics of the ossification centers of the twelfth thoracic vertebra in the human fetus, focusing on detailed linear, surface, and volumetric parameters of both the vertebral body and neural processes. METHODS: The investigation was based on 55 human fetuses (27 males, 28 females) aged 17-30 weeks of gestation. High-resolution low-dose computed tomography, three-dimensional reconstruction, digital image analysis and appropriate statistical modeling were used to obtain detailed morphometric measurements. RESULTS: All measured morphometric parameters of the Th12 vertebral body ossification center-transverse and sagittal diameters, cross-sectional area, and volume-increased linearly with gestational age (R2 = 0.94-0.97). A similar linear growth pattern was demonstrated for the length, width, cross-sectional area, and volume of the right and left neural process ossification centers (R2 = 0.97-0.98). No statistically significant sex-related or side-related differences were found, allowing the establishment of single normative growth curves for each parameter. CONCLUSIONS: This study provides the first comprehensive CT-based normative data for the ossification centers of the fetal Th12 vertebra in the second and early third trimesters. The presented linear growth models and reference values may assist anatomists, radiologists, obstetricians, and pediatric spine surgeons in estimating fetal age, and in the prenatal and postnatal assessment of congenital spinal anomalies, especially at the thoracolumbar junction. Further research on larger and broader gestational cohorts is warranted to validate and extend these findings.