PurposeKnowledge on the normative growth of the spine is critical in the prenatal detection of its abnormalities. We aimed to study the size of T6 vertebra in human fetuses with the crown-rump length of 115–265 mm.Materials and methodsUsing the methods of computed tomography (Biograph mCT), digital image analysis (Osirix 3.9) and statistics, the normative growth of the T6 vertebral body and the three ossification centers of T6 vertebra in 55 spontaneously aborted human fetuses (27 males, 28 females) aged 17–30 weeks were studied.ResultsNeither male–female nor right–left significant differences were found. The height, transverse, and sagittal diameters of the T6 vertebral body followed natural logarithmic functions as y = −4.972 + 2.732 × ln(age) ± 0.253 (R2 = 0.72), y = −14.862 + 6.426 × ln(age) ± 0.456 (R2 = 0.82), and y = −10.990 + 4.982 × ln(age) ± 0.278 (R2 = 0.89), respectively. Its cross-sectional area (CSA) rose proportionately as y = −19.909 + 1.664 × age ± 2.033 (R2 = 0.89), whereas its volumetric growth followed the four-degree polynomial function y = 19.158 + 0.0002 × age4 ± 7.942 (R2 = 0.93). The T6 body ossification center grew logarithmically in both transverse and sagittal diameters as y = −14.784 + 6.115 × ln(age) ± 0.458 (R2 = 0.81) and y = −12.065 + 5.019 × ln(age) ± 0.315 (R2 = 0.87), and proportionately in both CSA and volume like y = −15.591 + 1.200 × age ± 1.470 (R2 = 0.90) and y = −22.120 + 1.663 × age ± 1.869 (R2 = 0.91), respectively. The ossification center-to-vertebral body volume ratio was gradually decreasing with age. On the right and left, the neural ossification centers revealed the following models: y = −15.188 + 6.332 × ln(age) ± 0.629 (R2 = 0.72) and y = −15.991 + 6.600 × ln(age) ± 0.629 (R2 = 0.74) for length, y = −6.716 + 2.814 × ln(age) ± 0.362 (R2 = 0.61) and y = −7.058 + 2.976 × ln(age) ± 0.323 (R2 = 0.67) for width, y = −5.665 + 0.591 × age ± 1.251 (R2 = 0.86) and y = −11.281 + 0.853 × age ± 1.653 (R2 = 0.78) for CSA, and y = −9.279 + 0.849 × age ± 2.302 (R2 = 0.65) and y = −16.117 + 1.155 × age ± 1.832 (R2 = 0.84) for volume, respectively.ConclusionsNeither sex nor laterality differences are found in the morphometric parameters of evolving T6 vertebra and its three ossification centers. The growth dynamics of the T6 vertebral body follow logarithmically for its height, and both sagittal and transverse diameters, linearly for its CSA, and four-degree polynomially for its volume. The three ossification centers of T6 vertebra increase logarithmically in both transverse and sagittal diameters, and linearly in both CSA and volume. The age-specific reference intervals for evolving T6 vertebra present the normative values of potential relevance in the diagnosis of congenital spinal defects.

Using anatomical, hydrostatic, and statistical methods, liver volumes were assessed in 69 human fetuses of both sexes aged 18–30 weeks. No sex differences were found. The median of liver volume achieved by hydrostatic measurements increased from 6.57 cm3 at 18–21 weeks through 14.36 cm3 at 22–25 weeks to 20.77 cm3 at 26–30 weeks, according to the following regression: y = −26.95 + 1.74 × age ± Z  × (−3.15 + 0.27 × age). The median of liver volume calculated indirectly according to the formula liver volume = 0.55 × liver length × liver transverse diameter × liver sagittal diameter increased from 12.41 cm3 at 18–21 weeks through 28.21 cm3 at 22–25 weeks to 49.69 cm3 at 26–30 weeks. There was a strong relationship (r = 0.91, p < 0.001) between the liver volumes achieved by hydrostatic (x) and indirect (y) methods, expressed by y = −0.05 + 2.16x  ± 7.26. The liver volume should be calculated as follows liver volume = 0.26 × liver length × liver transverse diameter × liver sagittal diameter. The age-specific liver volumes are of great relevance in the evaluation of the normal hepatic growth and the early diagnosis of fetal micro- and macrosomias.

PurposesA satisfactory understanding of the clavicle development may be contributing to both the diagnosis of its congenital defects and prevention of perinatal damage to the shoulder girdle. This study was carried out to examine the transverse and sagittal diameters, cross-sectional area and volume of the two fused primary ossification centers of the clavicle.MethodsUsing the methods of CT, digital-image analysis and statistics, the size for two fused primary ossification centers of the clavicle in 42 spontaneously aborted human fetuses at ages of 18–30 weeks was studied.ResultsWithout any male–female and right-left significant differences, the best fit growth models for two fused primary ossification centers of the clavicle were as follows: y = −31.373 + 15.243 × ln(age) ± 1.424 (R2 = 0.74) for transverse diameter, y = −7.945 + 3.225 × ln(age) ± 0.262 (R2 = 0.78), y = −4.503 + 2.007 × ln(age) ± 0.218 (R2 = 0.68), and y = −4.860 + 2.117 × ln(age) ± 0.200 (R2 = 0.73) for sagittal diameters of the lateral, middle and medial ends respectively, y = −31.390 + 2.432 × age ± 4.599 (R2 = 0.78) for cross-sectional area, and y = 28.161 + 0.00017 × (age)4 ± 15.357 (R2 = 0.83) for volume.ConclusionsWith no sex and laterality differences, the fused primary ossification centers of the clavicle grow logarithmically in both transverse and sagittal diameters, linearly in cross-sectional area, and fourth-degree polynomially in volume. Our normative quantitative findings may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the clavicle in European human fetuses.