Morphometric study of the diaphragmatic surface of the liver in the human fetus.

This study aimed to examine age-specific reference intervals and growth dynamics of the best fit for liver dimensions on the diaphragmatic surface of the fetal liver. The research material consisted of 69 human fetuses of both sexes (32♂, 37♀) aged 18-30 weeks. Using methods of anatomical dissection, digital image analysis and statistics, a total of 10 measurements and 2 calculations were performed. No statistical significant differences between sexes were found (p>0.05). The parameters studied displayed growth models that followed natural logarithmic functions. The mean value of the transverse-to-vertical diameter ratio of the liver throughout the analyzed period was 0.71±0.11. The isthmic ratio decreased significantly from 0.81±0.12 in the 18-19th week to 0.62±0.06 in the 26-27th week, and then increased to 0.68±0.11 in the 28-30th week of fetal life (p<0.01). The morphometric parameters of the diaphragmatic surface of the liver present age-specific reference data. No sex differences are found. The transverse-to-vertical diameter ratio supports a proportionate growth of the fetal liver. Quantitative anatomy of the growing liver may be of relevance in both the ultrasound monitoring of the fetal development and the early detection of liver anomalies.

Quantitative anatomy of the liver visceral surface in the human fetus.

BACKGROUND: Understanding liver growth is relevant in both determining the status of normative fetal development and prenatal detection of its disorders. OBJECTIVES: This study attempted to examine age-specific reference intervals and the best-fit growth dynamics of the liver visceral surface for hepatic height, length, isthmic diameter, oblique diameters, circumferences of individual lobes, and total liver circumference. MATERIAL AND METHODS: Using anatomical, digital and statistical methods, the liver visceral surface was measured in 69 human fetuses of both sexes (32 males and 37 females) aged 18-30 weeks, derived from spontaneous abortions and stillbirths. RESULTS: The statistical analysis showed no sex differences. The best growth models mostly followed natural logarithmic functions, except for the length of the fissure for ligamentum teres hepatis and the length of fossa for gallbladder, which increased commensurately. Neither the length of fissure for ductus venosus nor the length of sulcus for inferior vena cava modeled the best-fit curves. The vertical-to-transverse diameter ratio of the liver was constant and averaged 0.75 ±0.12, while the isthmus ratio significantly altered from 0.78 ±0.07 at 18-19 weeks through 0.68 ±0.05 at 26-27 weeks to 0.72 ±0.07 at 28-30 weeks of gestation. CONCLUSIONS: With no sexual differences, the liver morphometric parameters increased either logarithmically (lengths of: transverse diameter, vertical diameter, right oblique diameter, left oblique diameter, isthmic diameter and porta hepatis, circumferences of: right lobe, left lobe, quadrate lobe, caudate lobe, and total liver circumference) or proportionately (length of fissure for ligamentum teres hepatis, length of fossa for gallbladder). The quantitative data of the growing liver may be relevant in both the ultrasound monitoring of fetuses and early detection of congenital liver anomalies.

Quantitative anatomy of the growing quadratus lumborum in the human foetus.

PURPOSES: The purpose of the study was to quantitatively evaluate the size of the quadratus lumborum and to precisely display its growth dynamics in the human foetus. MATERIALS AND METHODS: Using anatomical dissection, digital-image analysis (NIS Elements AR 3.0) and statistical analysis (Student's t test, regression analysis), the length, width, surface area, and cross-sectional area of the quadratus lumborum were measured, and the width-to-length ratio was calculated in 58 human foetuses of both sexes (26♂, 32♀) aged 16-27 weeks. RESULTS: Neither sex nor right-left significant differences were found in relation with the numerical data of the growing quadratus lumborum. The length, width, and cross-sectional area of the quadratus lumborum muscle increased logarithmically, while its surface area increased proportionately to fetal age. The following growth models were computed for the quadratus lumborum: y = -70.397 + 68.501 × ln(age) ± 1.170 for length, y = -20.435 + 8.815 × ln(age) ± 0.703 for width, y = -196.035 + 14.838 × age ± 13.745 for surface area, and y = -48.958 + 20.909 × ln(age) ± 1.100 for cross-sectional area. CONCLUSIONS: The fetal quadratus lumborum reveals neither sex nor bilateral differences. An increase in length and width of the growing quadratus lumborum follows in a commensurate fashion. The quadratus lumborum grows logarithmically with respect to its length, width, and cross-sectional area, and proportionately to age with respect to its surface area.

Quantitative anatomy of the growing clavicle in the human fetus: CT, digital image analysis, and statistical study.

PURPOSES: Knowledge of dimensions of fetal long bones is useful in both the assessment of fetal growth and early detection of inherited defects. Measurements of the fetal clavicle may facilitate detection of numerous defects, e.g., cleidocranial dysplasia, Holt-Oram syndrome, Goltz syndrome, and Melnick-Needles syndrome. METHODS: Using the methods of CT, digital image analysis, and statistics, the size of the growing clavicle in 42 spontaneously aborted human fetuses (21 males and 21 females) at ages of 18-30 weeks was studied. RESULTS: Without any male-female and right-left significant differences, the best fit growth models for the growing clavicle with relation to age in weeks were as follows: y = -54.439 + 24.673 × ln(age) ± 0.237 (R 2 = 0.86) for length, y = -12.042 + 4.906 × ln(age) ± 0.362 (R 2 = 0.82) for width of acromial end, y = -4.210 + 2.028 × ln(age) ± 0.177 (R 2 = 0.77) for width of central part, y = -4.687 + 2.364 × ln(age) ± 0.242 (R 2 = 0.70) for width of sternal end, y = -51.078 + 4.174 × ln(age) ± 6.943 (R 2 = 0.82) for cross-sectional area, and y = -766.948 + 281.774 × ln(age) ± 19.610 (R 2 = 0.84) for volume. CONCLUSIONS: With no sex and laterality differences, the clavicle grows logarithmically with respect to its length, width, and volume, and linearly with respect to its projection surface area. The obtained morphometric data of the growing clavicle are considered normative for their respective weeks of gestation and may be of relevance in the diagnosis of congenital defects.

Morphometric study of the two fused primary ossification centers of the clavicle in the human fetus.

PURPOSES: A 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. METHODS: Using 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. RESULTS: Without 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 (R (2) = 0.74) for transverse diameter, y = -7.945 + 3.225 × ln(age) ± 0.262 (R (2) = 0.78), y = -4.503 + 2.007 × ln(age) ± 0.218 (R (2) = 0.68), and y = -4.860 + 2.117 × ln(age) ± 0.200 (R (2) = 0.73) for sagittal diameters of the lateral, middle and medial ends respectively, y = -31.390 + 2.432 × age ± 4.599 (R (2) = 0.78) for cross-sectional area, and y = 28.161 + 0.00017 × (age)(4) ± 15.357 (R (2) = 0.83) for volume. CONCLUSIONS: With 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.

Volumetric Growth of the Liver in the Human Fetus: An Anatomical, Hydrostatic, and Statistical Study.

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 cm(3) at 18-21 weeks through 14.36 cm(3) at 22-25 weeks to 20.77 cm(3) 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 cm(3) at 18-21 weeks through 28.21 cm(3) at 22-25 weeks to 49.69 cm(3) 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.

Novel patterns for the growing main bronchi in the human fetus: an anatomical, digital and statistical study.

PURPOSE: Intensive progress in prenatal medicine results in performing airway management in the fetus affected by life-threatening congenital malformations. This study aimed to examine age-specific reference intervals and growth dynamics for length, proximal and distal external transverse diameters, and projection surface areas of the two main bronchi at varying gestational ages, including their relative growth in length and projection surface area. MATERIALS AND METHODS: Using anatomical dissection, digital image analysis and statistics, length, proximal and distal external transverse diameters, and projection surface areas of the right and left main bronchi were examined in 73 human fetuses (39 males, 34 females) aged 14-25 weeks, derived from spontaneous abortions and stillbirths. RESULTS: Statistical analysis showed no sex differences. Between the 14 and 25th week of gestation, the lengths of the right and left main bronchi increased from 1.43 ± 0.18 to 3.18 ± 0.39 mm, and from 2.97 ± 0.16 to 7.58 ± 1.95 mm, in accordance with the functions: [Formula: see text], respectively. The proximal external transverse diameters of the right and left main bronchi varied from 2.13 ± 0.41 to 4.24 ± 0.20 mm, and from 1.84 ± 0.06 to 3.67 ± 0.66 mm, following the logarithmic models: [Formula: see text], respectively. The distal external transverse diameter rose from 2.09 ± 0.47 to 4.24 ± 0.20 mm, as [Formula: see text] for the right main bronchus, and from 1.85 ± 0.04 to 3.67 ± 0.66 mm, like [Formula: see text] for the left one. On either side, there were no statistically significant differences between values of the proximal and distal transverse diameters of the main bronchus. The projection surface areas of the right and left main bronchi ranged from 2.95 ± 0.19 to 13.34 ± 2.12 mm(2), and from 5.57 ± 0.21 to 28.52 ± 5.24 mm(2), as [Formula: see text] and [Formula: see text]. The two main bronchi revealed a proportionate increase in both length and projection surface area, since the right-to-left bronchial length ratio and the right-to-left bronchial projection surface area ratio were stable, 0.41 ± 0.07 and 0.47 ± 0.08, respectively, throughout the analyzed period. CONCLUSIONS: The main bronchi show no sex differences. The right and left main bronchi grow logarithmically in length and external transverse diameter, and linearly in projection surface area. The right and left main bronchi evolve proportionately, with the right-to-left bronchial ratios of 0.41 ± 0.07 for length, and 0.47 ± 0.08 for projection surface area.

Morphometric study of the T6 vertebra and its three ossification centers in the human fetus.

PURPOSE: Knowledge 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 METHODS: Using 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. RESULTS: Neither 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 (R (2) = 0.72), y = -14.862 + 6.426 × ln(age) ± 0.456 (R (2) = 0.82), and y = -10.990 + 4.982 × ln(age) ± 0.278 (R (2) = 0.89), respectively. Its cross-sectional area (CSA) rose proportionately as y = -19.909 + 1.664 × age ± 2.033 (R (2) = 0.89), whereas its volumetric growth followed the four-degree polynomial function y = 19.158 + 0.0002 × age(4) ± 7.942 (R (2) = 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 (R (2) = 0.81) and y = -12.065 + 5.019 × ln(age) ± 0.315 (R (2) = 0.87), and proportionately in both CSA and volume like y = -15.591 + 1.200 × age ± 1.470 (R (2) = 0.90) and y = -22.120 + 1.663 × age ± 1.869 (R (2) = 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 (R (2) = 0.72) and y = -15.991 + 6.600 × ln(age) ± 0.629 (R (2) = 0.74) for length, y = -6.716 + 2.814 × ln(age) ± 0.362 (R (2) = 0.61) and y = -7.058 + 2.976 × ln(age) ± 0.323 (R (2) = 0.67) for width, y = -5.665 + 0.591 × age ± 1.251 (R (2) = 0.86) and y = -11.281 + 0.853 × age ± 1.653 (R (2) = 0.78) for CSA, and y = -9.279 + 0.849 × age ± 2.302 (R (2) = 0.65) and y = -16.117 + 1.155 × age ± 1.832 (R (2) = 0.84) for volume, respectively. CONCLUSIONS: Neither 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.