Nan Jian1,2, Mi-Mi Tian1, Lian-Xiang Xiao1, Hui Zhao3, Yan Shi1, Guan Li4, Shuai Zhang1, Xiang-Tao Lin5. 1. Shandong Medical Imaging Research Institute, Shandong University, No. 44 West Wenhua Road, Jinan, 250012, Shandong, China. 2. CT Department, Heze Municipal Hospital, No. 2888 West Caozhou Road, Heze, 274031, Shandong, China. 3. Department of Imaging, Shandong Provincial Hospital Affiliated to Shandong University, No. 324 Jingwu Road, Jinan, 250021, Shandong, China. 4. College of Radiology, Taishan Medical University, NO.619 Great Wall Road, Taian, 271016, Shandong, China. 5. Shandong Medical Imaging Research Institute, Shandong University, No. 44 West Wenhua Road, Jinan, 250012, Shandong, China. linxt@sdu.edu.cn.
Abstract
PURPOSE: To describe the temporal pattern of the appearance of the S1-Co1 centrum ossification centers (COCs) and provide reference data for the S1-S5 COCs and sacral length at various gestational ages (GAs). METHODS: Postmortem magnetic resonance imaging (MRI) was performed on 71 fetuses (GA, 17-42 weeks) using the 3D dual-echo steady-state with water excitation T2 sequence in the sagittal plane. To confirm the reliability of this sequence, the MRI data were compared with the CT and histologic data obtained from two fetuses (GAs, 21 and 30 weeks). The presence or absence of each sacrococcygeal COC was recorded. Sacral length and S1-S5 COC height, sagittal diameter, transverse diameter, cross-sectional area, and volume were measured. RESULTS: All fetuses showed S1-S3 COCs by 17 weeks, S4 COCs by 19 weeks, and S5 COCs by 28 weeks. The S4, S5, and Co-1 COCs were visualized in 70 (98.59%), 51 (71.83%), and 21 (29.58%) fetuses, respectively. Sacral length, height, sagittal, and transverse diameters increased linearly, while cross-sectional area and volume increased exponentially with advancing GA. Mean growth rates of the sagittal and transverse diameters, cross-sectional area, and volume, but not of height, significantly differed among the S1-S5 vertebrae. CONCLUSION: We have presented the timing of appearance of individual sacrococcygeal COCs and the age-specific, normative MRI reference values for sacral length and the morphometric parameters of the sacral COCs, which are of clinical importance in the diagnosis of congenital sacral abnormalities and skeletal dysplasia.
PURPOSE: To describe the temporal pattern of the appearance of the S1-Co1 centrum ossification centers (COCs) and provide reference data for the S1-S5 COCs and sacral length at various gestational ages (GAs). METHODS: Postmortem magnetic resonance imaging (MRI) was performed on 71 fetuses (GA, 17-42 weeks) using the 3D dual-echo steady-state with water excitation T2 sequence in the sagittal plane. To confirm the reliability of this sequence, the MRI data were compared with the CT and histologic data obtained from two fetuses (GAs, 21 and 30 weeks). The presence or absence of each sacrococcygeal COC was recorded. Sacral length and S1-S5 COC height, sagittal diameter, transverse diameter, cross-sectional area, and volume were measured. RESULTS: All fetuses showed S1-S3 COCs by 17 weeks, S4 COCs by 19 weeks, and S5 COCs by 28 weeks. The S4, S5, and Co-1 COCs were visualized in 70 (98.59%), 51 (71.83%), and 21 (29.58%) fetuses, respectively. Sacral length, height, sagittal, and transverse diameters increased linearly, while cross-sectional area and volume increased exponentially with advancing GA. Mean growth rates of the sagittal and transverse diameters, cross-sectional area, and volume, but not of height, significantly differed among the S1-S5 vertebrae. CONCLUSION: We have presented the timing of appearance of individual sacrococcygeal COCs and the age-specific, normative MRI reference values for sacral length and the morphometric parameters of the sacral COCs, which are of clinical importance in the diagnosis of congenital sacral abnormalities and skeletal dysplasia.
Entities:
Keywords:
Fetal spine; Mixed-effects model; Ossification center; Sacrococcygeal vertebrae; Three-dimensional dual-echo steady-state with water excitation T2 sequence