Distal Transverse Diameter Research Articles

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

PurposesTibial 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 methodsWith 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.ResultsWithout 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.ConclusionsThe 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.

Quantitative anatomy of the primary ossification center of the femoral shaft in human fetuses

PurposeEarly 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 methodsUsing 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.ResultsWith 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 (R2 = 0.86) for its length, y = −3.579 + 0.368 × age ± 0.529 (R2 = 0.88) for its proximal transverse diameter, y = −1.105 + 0.187 × age ± 0.309 (R2 = 0.84) for its middle transverse diameter, y = −2.321 + 0.323 × age ± 0.558 (R2 = 0.83) for its distal transverse diameter, y = −50.306 + 0.308 × (age)2 ± 18.289 (R2 = 0.90) for its projection surface area, and y = −91.458 + 0.390 × (age)3 ± 92.146 (R2 = 0.88) for its volume.ConclusionsThe 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.

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

PurposeIntensive 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 methodsUsing 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.ResultsStatistical 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: y = - 4.850 + 2.452 x ; text{ln}left( {text{Age}} right) pm 0.400;{text{and}};y = - 15.005 + 7.093x ; text{ln} left( {text{Age}} right) pm 0.579 , 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: y = - 8.666 + 4.018x ; text{ln}{rm (Age)} pm 0.367;{text{and}};y = - 6.938 + 3.305x{text{ ln(Age) }} pm 0.323 , respectively. The distal external transverse diameter rose from 2.09 ± 0.47 to 4.24 ± 0.20 mm, as y = - 8.723 + 4.021x{text{ ln(Age)}} pm 0.392 for the right main bronchus, and from 1.85 ± 0.04 to 3.67 ± 0.66 mm, like y = - 6.924 + 3.280x{text{ ln(Age)}} pm 0.348 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 mm2, and from 5.57 ± 0.21 to 28.52 ± 5.24 mm2, as y = - 10.212 + 0.943x{text{ Age}} pm 1.739 and y = - 19.119 + 1.875x{text{ Age}} pm 3.054 . 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.ConclusionsThe 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.

Tracheal dimensions in human fetuses: an anatomical, digital and statistical study

PurposeRapid advances in perinatal medicine have resulted in increased number of various tracheo-bronchial interventions on fetal and neonatal airways. The present study was performed to compile normative data for external dimensions of the trachea at varying gestational age.Materials and methodsUsing anatomical dissection, digital image analysis (NIS-Elements BR 3.0) and statistical analysis (ANOVA, regression analysis), a range of measurements (prebifurcation and bifurcation lengths, proximal and distal external transverse diameters, proximal external cross-sectional area, and external volume) for the trachea in 73 spontaneously aborted fetuses (39 male, 34 female) aged 14–25 weeks was examined.ResultsNo significant male–female differences were found (P > 0.05). The prebifurcation and bifurcation lengths ranged from 8.14 ± 1.90 to 20.77 ± 0.50 mm and from 2.23 ± 0.25 to 5.77 ± 0.76 mm, according to the functions y = −54.291 + 23.940 × ln (Age) ± 1.681 (R 2 = 0.78) and y = −10.756 + 4.860 × ln (Age) ± 0.731 (R 2 = 0.44), respectively. Their relative growth, expressed as the bifurcation-to-prebifurcation length ratio, was stable from the age of 16 weeks and attained the value 0.22 ± 0.05. The proximal external transverse diameter of the trachea was greater (36 fetuses, 49.3%), smaller (34 fetuses, 46.6%) or similar (3 fetuses, 4.1%), when compared to the distal external transverse diameter. The values for proximal and distal transverse diameters ranged from 2.39 ± 0.04 to 5.20 ± 0.17 mm and from 2.42 ± 0.20 to 4.93 ± 0.08 mm, expressed by the functions: y = −9.659 + 4.574 × ln (Age) ± 0.313 (R 2 = 0.79) and y = −10.897 + 4.984 × ln (Age) ± 0.327 (R 2 = 0.81). The values of proximal external cross-sectional area ranged from 3.38 ± 0.12 to 15.98 ± 1.04 mm2, according to the linear function y = −11.798 + 1.077 × Age ± 1.463 (R 2 = 0.78). The values of external volume of the trachea ranged from 34.3 ± 11.6 to 370.6 ± 94.1 mm3 and generated the quadratic function y = −154.589 + 0.858 × Age2 ± 34.196 (R 2 = 0.87).ConclusionsThe tracheal parameters do not show male–female differences. The developmental dynamics of prebifurcation and bifurcation lengths and proximal and distal external transverse diameters of the trachea follow linear functions dependent on the natural logarithm of fetal age, its external cross-sectional area—according to a linear function, and its external volume—according to a quadratic function.