Application of artificial neural networks to evaluate femur development in the human fetus.

The present article concentrates on an innovative analysis that was performed to assess the development of the femur in human fetuses using artificial intelligence. As a prerequisite, linear dimensions, cross-sectional surface areas and volumes of the femoral shaft primary ossification center in 47 human fetuses aged 17-30 weeks, originating from spontaneous miscarriages and preterm deliveries, were evaluated with the use of advanced imaging techniques such as computed tomography and digital image analysis. In order to ensure the data representativeness and to avoid introducing any hidden structures that may exist in the data, the entire dataset was randomized and separated into three subsets: training (50% of cases), testing (25% of cases), and validation (25% of cases). Based on the collected numerical data, an artificial neural network was devised, trained, and subject to testing in order to synchronously estimate five parameters of the femoral shaft primary ossification center, thus leveraging fundamental information such as gestational age and femur length. The findings reveal the formulated multi-layer perceptron model denoted as MLP 2-3-2-5 to exhibit robust predictive efficacy, as evidenced by the linear correlation coefficient between actual values and network outputs: R = 0.955 for the training dataset, R = 0.942 for validation, and R = 0.953 for the testing dataset. The authors have cogently demonstrated that the use of an artificial neural network to assess the growing femur in the human fetus may be a valuable tool in prenatal tests, enabling medical doctors to quickly and precisely assess the development of the fetal femur and detect potential anatomical abnormalities.

Quantitative anatomy of the extensor digiti minimi muscle in the growing human fetus.

Introduction Age-specific reference intervals for the extensor digiti minimi muscle (EDMM) in the human fetus may be relevant in the detailed evaluation of the musculoskeletal systems with potential relevant aspects for surgical treatment. The aim of the study was to examine the age-specific reference intervals and growth dynamics of the EDMM in relation to its length, width, projection surface area and volume. Material and methods The examined material included 70 human formalin-fixed fetuses of both sexes (37♀, 33♂) aged from 17 to 29 weeks. With the use of anatomical dissection every EDMM was visualized, recorded in a form of JPG formats and analyzed by the digital image analysis system and statistical methods. Results No variability of the EDMM was found. All the morphometric parameters of the EDMM revealed neither sex nor laterality differences. With fetal age most linear parameters of the EDMM concerning its examined lengths and widths increased in accordance with natural logarithmic functions. The only two exceptions to this referred to the belly width of EDMM measured at its mid-length and the tendon width of EDMM measured proximal to the extensor retinaculum of wrist, which both followed square root functions. The projection surface areas of the EDMM followed natural logarithmic functions, while the volumetric growth of the EDMM was proportionate to fetal age. Conclusions The variability of the EDMM in the human fetus is minimal. The morphometric data of the EDMM represents age-specific reference intervals of clinical significance. Morphometric parameters of the EDMM reveal neither sex nor laterality differences. The EDMM displays three different growth dynamics: from gradual growth deceleration according to both natural logarithmic functions (total length of the muscle and its tendons, belly length, tendon lengths, belly width at its origin, tendon width at its insertion, and projection surface areas) and square root functions (belly width at its mid-length and tendon width in the pre-retinacular segment) to a proportionate growth (total volume).

Quantitative study of the popliteal fossa in the human fetus.

The popliteal fossa presents an extensive diamond-shaped topographical element on the posterior aspect of the knee. With the use of classical anatomical dissection, digital image analysis of NIS Elements AR 3.0 and statistics we morphometrically analyzed the size of the popliteal fossa in human fetuses aged 17-29 weeks of gestation. Morphometric parameters of the popliteal fossa increased logarithmically with fetal age: y = -44.421 + 24.301 × ln (Age) for length of superomedial boundary, y = -41.379 + 22.777 × ln (Age) for length of superolateral boundary, y = -39.019 + 20.981 × ln (Age) for inferomedial boundary, y = -37.547 + 20.319 × ln (Age), for length of inferolateral boundary, y = -28.915 + 15.822 × ln (Age) for transverse diameter, y = -69.790 + 38.73 × ln (Age) for vertical diameter and y = -485.631 + 240.844 × ln (Age) for projection surface area. Out of the four angles of the popliteal fossa the medial one was greatest, the inferior one the smallest, while the lateral one was somewhat smaller than the medial one and approximately three times greater than the superior one, with no difference with fetal age. In terms of morphometric parameters the popliteal fossa in the human fetus displays neither male-female nor right-left differences. In the popliteal fossa, growth patterns of its four boundaries, vertical and transverse diameters, and projection surface area all follow natural logarithmic functions. All the morphometric data is considered age-specific reference intervals, which may be conducive in the diagnostics of congenital abnormalities in the human fetus.

Quantitative anatomy of the fused ossification center of the occipital squama in the human fetus.

CT-based quantitative analysis of any ossification center in the cranium has not previously been carried out due to the limited availability of human fetal material. Detailed morphometric data on the development of ossification centers in the human fetus may be useful in the early detection of congenital defects. Ossification disorders in the cranium are associated with either a delayed development of ossification centers or their mineralization. These aberrations may result in the formation of accessory skull bones that differ in shape and size, and the incidence of which may be misdiagnosed as, e.g., skull fractures. The study material comprised 37 human fetuses of both sexes (16♂, 21♀) aged 18-30 weeks. Using CT, digital image analysis software, 3D reconstruction and statistical methods, the linear, planar and spatial dimensions of the occipital squama ossification center were measured. The morphometric characteristics of the fused ossification center of the occipital squama show no right-left differences. In relation to gestational age, the ossification center of the occipital squama grows linearly in its right and left vertical diameters, logarithmically in its transverse diameters of both the interparietal and supraoccipital parts and projection surface area, and according to a quadratic function in its volume. The obtained numerical findings of the occipital squama ossification center may be considered age-specific references of relevance in both the estimation of gestational age and the diagnostic process of congenital defects.

Morphometric study of the primary ossification center of the frontal squama in the human fetus.

PURPOSES: Detailed morphometric data on the development of ossification centers in human fetuses is useful in the early detection of skeletal dysplasias associated with a delayed development of ossification centers and their mineralization. Quantitative analysis of primary ossification centers of cranial bones is sporadic due to limited availability of fetal material. MATERIAL AND METHODS: The size of the primary ossification center of the frontal squama in 37 human (16 males and 21 females) spontaneously aborted human fetuses aged 18-30 weeks was studied by means of CT, digital-image analysis and statistics. RESULTS: With neither sex nor laterality differences, the best-fit growth dynamics for the primary ossification center of the frontal squama was modelled by the following functions: y = 13.756 + 0.021 × (age)2 ± 0.024 for its vertical diameter, y = 0.956 + 0.956 × age ± 0.823 for its transverse diameter, y = 38.285 + 0.889 × (age)2 ± 0.034 for its projection surface area, and y = 90.020 + 1.375 × (age)2 ± 11.441 for its volume. CONCLUSIONS: Our findings for the primary ossification center of the frontal squama may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the skull in human fetuses.

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 primary ossification center in the fetal pubis bone.

PURPOSES: Skeletodysplasiae and hereditary dysostoses constitute a group of over 350 disorders of the skeletal system. Knowledge about development of the pubic primary ossification center may be useful in both determining the fetal stage and maturity, and for detecting congenital disorders. The present study was performed to quantitatively examine the pubic primary ossification center with respect to its linear, planar, and volumetric parameters. MATERIALS AND METHODS: Using methods of computed tomography (CT), digital-image analysis and statistics, the size of the pubic primary ossification center in 33 spontaneously aborted human fetuses (18 males and 15 females) aged 22-30 weeks was studied. RESULTS: With no sex and laterality differences, the best-fit growth dynamics for the pubic primary ossification center was modeled by the following functions: y = - 13.694 + 0.728 × age ± 0.356 for its sagittal diameter, y = - 3.350 + 0.218 × age ± 0.159 for its vertical diameter, y = - 61.415 + 2.828 × age ± 1.519 for its projection surface area, and y = - 65.801 + 3.173 × age ± 2.149 for its volume. CONCLUSIONS: The size of the pubic primary ossification center shows neither sex nor laterality differences. The growth dynamics of the vertical and sagittal diameters, projection surface area, and volume of the pubic ossification centers follow proportionately to fetal age. The obtained numerical findings of the pubic ossification center are considered age-specific reference data with clinical implications in the diagnostics of congenital defects.

Three-dimensional growth of tibial shaft ossification in the human fetus: a digital-image and statistical analysis.

PURPOSES: Tibial shaft ossification in terms of its size and growth may be criticalin describing both the fetal stage and maturity, and in identifying innate disorders. The present study was executed to quantitatively assess ossification of the tibial shaft, taking its morphometric linear, planar and volumetric parameters into account. MATERIALS AND METHODS: With the use of methods of CT, digital-image analysis and statistics, the evolutionof tibial shaft ossification in 47 spontaneously aborted human fetuses at the age of 17-30 weeks was studied. RESULTS: Without any male-female and right-left morphometric differences, the best fit growth dynamics fortibial shaft ossification was modelled by the following functions: y = 5.312 + 0.034 × (age)2 ± 0.001 (R2 = 0.89) for its length, y = - 2.855 + 0.307 × age ± 0.009 (R2 = 0.96) for its proximal transverse diameter, y = - 0.758 + 0.153 × age ± 0.005 (R2 = 0.88) for its middle transverse diameter, y = - 1.844 + 0.272 × age ± 0.09 (R2 = 0.90) for its distal transverse diameter, y = - 40.263 + 0.258 × (age)2 ± 0.007 (R2 = 0.94) for its projection surface area, and y = - 287.996 + 1.186 × (age)2 ± 0.037 (R2 = 0.92) for its volume. The femoral-to-tibial ossification length ratio was 1.15 ± 0.1. CONCLUSIONS: The size of tibial shaft ossification displays neither sex nor laterality differences. Tibial shaft ossification follows quadratic functions with respect to its length, projection surface area and volume, and linear functions with respect to its proximal, middle and distal transverse diameters. The obtained morphometric data of tibial shaft ossification are considered normative age-specific references of relevance in both the estimation of fetal ages and the ultrasound diagnostics of congenital defects.

Morphometric study of the primary ossification center of the fibular shaft in the human fetus.

PURPOSES: Precise morphometric data on the development of ossification centers in human fetuses may be useful in the early detection of skeletal dysplasias associated with delayed ossification center development and mineralization. The present study was performed to quantitatively examine the primary ossification center of the fibular shaft with respect to its linear, planar and volumetric parameters. MATERIALS AND METHODS: Using methods of CT, digital-image analysis (Osirix 3.9 MD) and statistics (Student's t-test, Shapiro-Wilk, Fisher's test, Tukey's test, Kruskal-Wallis test, regression analysis), the size of the primary ossification center of the fibular shaft in 47 spontaneously aborted human fetuses (25 ♂ and 22 ♀) aged 17-30 weeks was studied. In each fetus, the assessment of linear dimensions (length, transverse diameters for: proximal end, middle part and distal end), projection surface area and volume of the fibular shaft ossification center was carried out. RESULTS: With no sex and laterality differences, the best fit growth dynamics for the primary ossification center of the fibular shaft was modelled by the following functions: y = - 13.241 + 1.567 × age ± 1.556 (R2 = 0.94) for its length, y = - 0.091 + 0.063 × age ± 0.073 (R2 = 0.92) for its proximal transverse diameter, y = - 1.201 + 0.717 × ln(age) ± 0.054 (R2 = 0.83) for its middle transverse diameter, y = - 2.956 + 1.532 × ln(age) ± 0.090 (R2 = 0.89) for its distal transverse diameter, y = - 69.038 + 4.699 × age ± 4.055 (R2 = 0.95) for its projection surface area, and y = - 126.374 + 9.462 × age ± 8.845 (R2 = 0.94) for its volume. CONCLUSIONS: The ossification center in the fibular shaft follows linear functions with respect to its length, proximal transverse diameter, projection surface area and volume, and natural logarithmic functions with respect to its middle and distal transverse diameters. The obtained morphometric data of the fibular shaft ossification center is considered normative for their respective prenatal weeks and may be of relevance in both the estimation of fetal age and the ultrasound diagnostics of congenital defects.

The primary ossification of the human fetal ischium: CT, digital-image analysis, and statistics.

PURPOSES: Details concerning the normal growth of the pelvic girdle in the fetus are of importance in the early detection of congenital defects. This study was executed to quantitatively evaluate the primary ossification center of the ischium with relation to its linear, planar and volumetric parameters. MATERIALS AND METHODS: Using methods of CT, digital-image analysis, and statistics, geometrical dimensions of the ischium's primary ossification center in 42 spontaneously aborted human fetuses (21 ♂ and 21 ♀) aged 18-30 weeks were calculated. RESULTS: With no sex and laterality differences, the best fit growth dynamics for the ischium's primary ossification center were displayed by the following functions: y = - 10.045 + 0.742 × age ± 0.013 (R2 = 0.97) for its vertical diameter, y = - 5.212 + 0.385 × age ± 0.008 (R2 = 0.97) for its sagittal diameter, y = - 36.401 + 0.122 × (age)2 ± 45.534 (R2 = 0.96) for its projection surface area, and y = - 1052.840 + 368.470 × ln(age) ± 12.705 (R2 = 0.91) for its volume. CONCLUSIONS: Neither male-female nor right-left differences are found for any of the morphometric parameters of the ischium's primary ossification center. With relation to fetal ages in weeks, the ischium's primary ossification center grows proportionately in vertical and sagittal diameters, second-degree polynomially in projection surface area, and logarithmically in volume. The quantitative findings of the ischium's primary ossification center are considered age-specific reference data of relevance in the diagnostics of innate defects.

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 ilium's primary ossification center in the human fetus.

PURPOSE: An understanding of the development of the ilium's primary ossification center may be useful in both determining the fetal stage and maturity, and for detecting congenital disorders. This study was performed to quantitatively examine the ilium's primary ossification center with respect to its linear, planar and volumetric parameters. MATERIALS AND METHODS: Using methods of CT, digital-image analysis and statistics, the size of the ilium's primary ossification center in 42 spontaneously aborted human fetuses of crown-rump length (CRL) ranged from 130 to 265 mm (aged 18-30 weeks) was studied. RESULTS: With no sex and laterality differences, the best fit growth dynamics for the ilium's primary ossification center was modelled by the following functions: y = - 63.138 + 33.413 × ln(CRL) ± 1.609 for its vertical diameter, y = - 59.220 + 31.353 × ln(CRL) ± 1.736 for its transverse diameter, y = - 105.681 + 1.137 × CRL ± 16.035 for its projection surface area, and y = 478.588 + 4.035 × CRL ± 14.332 for its volume. The shape of the ilium's primary ossification center did not change over the study period, because its transverse -to- vertical diameter ratio was stable at the level of 0.94 ± 0.07. Conclusions The size of the ilium's primary ossification center displays neither sex nor laterality differences. The ilium's primary ossification center grows logarithmically with respect to its vertical and transverse diameters, and linearly with respect to its projection surface area and volume. The shape of the ilium's primary ossification center does not change throughout the examined period. The obtained quantitative data of the ilium's primary ossification center is considered normative for respective prenatal weeks and may contribute to the prenatal ultrasound diagnostics of congenital defects.

Morphometric study of the triangle of Petit in human fetuses.

BACKGROUND: The inferior lumbar triangle of Petit is bounded by the iliac crest, lateral border of the latissimus dorsi and the medial border of the external oblique. OBJECTIVES: In the present study, we aimed to quantitatively examine the base, sides, area, and interior angles of the inferior lumbar triangle in the human fetus so as to provide their growth dynamics. MATERIAL AND METHODS: Using anatomical dissection, digital image analysis (NIS-Elements AR 3.0), and statistics (Student's t-test, regression analysis), we measured the base, 2 sides, area and interior angles of Petit's triangle in 35 fetuses of both sexes (16 male, 19 female) aged 14-24 weeks. RESULTS: Neither sex nor laterality differences were found. All the parameters studied increased commensurately with age. The linear functions were computed as follows: y = -0.427 + 0.302 × age for base, y = 1.386 + 0.278 × age for medial side, y = 0.871 + 0.323 × age for lateral side, and y = -13.230 + 1.590 × age for area of the Petit triangle. CONCLUSIONS: In terms of geometry, Petit triangle reveals neither male-female nor right-left differences. An increase in both lengths and area of the inferior lumbar triangle follows proportionately. The Petit triangle is an acute one in the human fetus.

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 primary ossification center of the femoral shaft in human fetuses.

PURPOSE: Early clinical distinction of congenital defects in the femur is extremely important, as it determines the prognosis of the development of the lower limb. This study was performed to quantitatively examine the primary center of ossification in the femoral shaft with respect to its linear, planar, and volumetric parameters. MATERIALS AND METHODS: Using methods of CT, digital-image analysis, and statistics, the size of the primary ossification center of the femoral shaft in 47 spontaneously aborted human fetuses aged 17-30 weeks was studied. RESULTS: With no sex and laterality differences, the best fit growth dynamics for femoral shaft ossification center was modelled by the following functions: y = 5.717 + 0.040 × (age)2 ± 2.905 (R 2 = 0.86) for its length, y = -3.579 + 0.368 × age ± 0.529 (R 2 = 0.88) for its proximal transverse diameter, y = -1.105 + 0.187 × age ± 0.309 (R 2 = 0.84) for its middle transverse diameter, y = -2.321 + 0.323 × age ± 0.558 (R 2 = 0.83) for its distal transverse diameter, y = -50.306 + 0.308 × (age)2 ± 18.289 (R 2 = 0.90) for its projection surface area, and y = -91.458 + 0.390 × (age)3 ± 92.146 (R 2 = 0.88) for its volume. CONCLUSIONS: The size of the femoral shaft ossification center displays neither sex nor laterality differences. The ossification center in the femoral shaft follows quadratic functions with respect to its length and projection surface area, linear functions with respect to its proximal, middle, and distal transverse diameters, and a cubic function with respect to its volume. The obtained morphometric data of the femoral shaft ossification center are considered normative for respective prenatal weeks and may be of relevance in both the estimation of fetal ages and the ultrasound diagnostics of congenital defects.

Quantitative Anatomy of the Trapezius Muscle in the Human Fetus.

BACKGROUND: The trapezius muscle consists of three parts that are capable of functioning independently. Its superior part together with the levator scapulae and rhomboids elevate the shoulder, the middle part retracts the scapula, while the inferior part lowers the shoulder. OBJECTIVES: The present study aimed to supplement numerical data and to provide growth dynamics of the trapezius in the human fetus. MATERIAL AND METHODS: Using methods of anatomical dissection, digital image analysis (NIS Elements AR 3.0), and statistics (Student's t-test, regression analysis), we measured the length, the width and the surface area of the trapezius in 30 fetuses of both sexes (13™ k,17™ … ) aged 13-19 weeks. RESULTS: Neither sex nor laterality differences were found. All the studied parameters of the trapezius increased proportionately with age. The linear functions were computed as follows: y = -103.288 + 10.514 × age (r = 0.957) for total length of the trapezius muscle, y = -67.439 + 6.689 × age (r = 0.856) for length of its descending part, y = -8.493 + 1.033 × age (r = 0.53) for length of its transverse part, y = -27.545 + 2.802 × age (r = 0.791) for length of its ascending part, y = -19.970 + 2.505 × age (r = 0.875) for width of the trapezius muscle, and y = -2670.458 + 212.029 × age (r = 0.915) for its surface area. CONCLUSIONS: Neither sex nor laterality differences exist in the numerical data of the trapezius muscle in the human fetus. The descending part of trapezius is the longest, while its transverse part is the shortest. The growth dynamics of the fetal trapezius muscle follows proportionately.

Morphometric study of the neural ossification centers of the atlas and axis in the human fetus.

PURPOSES: The knowledge of the developing cervical spine and its individual vertebrae, including their neural processes may be useful in the diagnostics of congenital vertebral malformations. This study was performed to quantitatively examine the neural ossification centers of the atlas and axis with respect to their linear, planar and volumetric parameters. METHODS: Using the methods of CT, digital-image analysis and statistics, the size of neural ossification centers in the atlas and axis in 55 spontaneously aborted human fetuses aged 17-30 weeks was studied. RESULTS: Without any male-female and right-left significant differences, the best fit growth dynamics for the neural ossification centers of the atlas and axis were, respectively, modelled by the following functions: for length: y = -13.461 + 6.140 × ln(age) ± 0.570 and y = -15.683 + 6.882 × ln(age) ± 0.503, for width: y = -4.006 + 1.930 × ln(age) ± 0.178 and y = -3.054 + 1.648 × ln(age) ± 0.178, for cross-sectional area: y = -7.362 + 0.780 × age ± 1.700 and y = -9.930 + 0.869 × age ± 1.911, and for volume: y = -6.417 + 0.836 × age ± 1.924 and y = -11.592 + 1.087 × age ± 2.509. CONCLUSIONS: The size of neural ossification centers of the atlas and axis shows neither sexual nor bilateral differences. The neural ossification centers of the atlas and axis grow logarithmically in both length and width and linearly in both cross-sectional area and volume. The numerical data relating to the size of neural ossification centers of the atlas and axis derived from the CT and digital-image analysis are considered specific-age reference values of potential relevance in both the ultrasound monitoring and the early detection of spinal abnormalities relating to the neural processes of the first two cervical vertebrae in the fetus.

Digital image analysis of ossification centers in the axial dens and body in the human fetus.

PURPOSES: The detailed understanding of the anatomy and timing of ossification centers is indispensable in both determining the fetal stage and maturity and for detecting congenital disorders. This study was performed to quantitatively examine the odontoid and body ossification centers in the axis with respect to their linear, planar and volumetric parameters. METHODS: Using the methods of CT, digital image analysis and statistics, the size of the odontoid and body ossification centers in the axis in 55 spontaneously aborted human fetuses aged 17-30 weeks was studied. RESULTS: With no sex difference, the best fit growth dynamics for odontoid and body ossification centers of the axis were, respectively, as follows: for transverse diameter y = -10.752 + 4.276 × ln(age) ± 0.335 and y = -10.578 + 4.265 × ln(age) ± 0.338, for sagittal diameter y = -4.329 + 2.010 × ln(age) ± 0.182 and y = -3.934 + 1.930 × ln(age) ± 0.182, for cross-sectional area y = -7.102 + 0.520 × age ± 0.724 and y = -7.002 + 0.521 × age ± 0.726, and for volume y = -37.021 + 14.014 × ln(age) ± 1.091 and y = -37.425 + 14.197 × ln(age) ± 1.109. CONCLUSIONS: With no sex differences, the odontoid and body ossification centers of the axis grow logarithmically in transverse and sagittal diameters, and in volume, while proportionately in cross-sectional area. Our specific-age reference data for the odontoid and body ossification centers of the axis may be relevant for determining the fetal stage and maturity and for in utero three-dimensional sonographic detecting segmentation anomalies of the axis.

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.

Quantitative Anatomy of the Growing Lungs in the Human Fetus.

Using anatomical, digital, and statistical methods we examined the three-dimensional growth of the lungs in 67 human fetuses aged 16-25 weeks. The lung dimensions revealed no sex differences. The transverse and sagittal diameters and the base circumference were greater in the right lungs while the lengths of anterior and posterior margins and the lung height were greater in the left lungs. The best-fit curves for all the lung parameters were natural logarithmic models. The transverse-to-sagittal diameter ratio remained stable and averaged 0.56 ± 0.08 and 0.52 ± 0.08 for the right and left lungs, respectively. For the right and left lungs, the transverse diameter-to-height ratio significantly increased from 0.74 ± 0.09 to 0.92 ± 0.08 and from 0.56 ± 0.07 to 0.79 ± 0.09, respectively. The sagittal diameter-to-height ratio significantly increased from 1.41 ± 0.23 to 1.66 ± 0.18 in the right lung, and from 1.27 ± 0.17 to 1.48 ± 0.22 in the left lung. In the fetal lungs, their proportionate increase in transverse and sagittal diameters considerably accelerates with relation to the lung height. The lung dimensions in the fetus are relevant in the evaluation of the normative pulmonary growth and the diagnosis of pulmonary hypoplasia.