Marcin Wiśniewski

New quantitative patterns of the growing trachea in human fetuses

Summary Background Rapid progress in perinatal medicine has resulted in numerous tracheo-bronchial interventions on fetal and neonatal airways. The present study was performed to compile normative data for tracheal dimensions at varying gestational ages. Material/Methods Using anatomical dissection, digital image analysis (NIS-Elements BR 3.0) and statistical analysis (Wilcoxon signed-rank test, Student’s t test, one-way ANOVA, post-hoc Bonferroni test, linear and nonlinear regression analysis) a range of the 4 variables (length in mm, middle external transverse diameter in mm, proximal internal cross-sectional area in mm2, internal volume in mm3) for the trachea in 73 spontaneously aborted human fetuses (39 male, 34 female) aged 14–25 weeks was examined. Results No significant male-female differences were found (P>0.05). The length ranged from 10.37±2.15 to 26.54±0.26 mm as y=−65.098 + 28.796 × ln (Age) ±1.794 (R2=0.82). The middle external transverse diameter varied from 2.53±0.09 to 5.09±0.42 mm with the model y=−11.020 + 5.049 × ln (Age) ±0.330 (R2=0.81). The trachea indicated a proportional evolution because the middle external transverse diameter-to-length ratio was stable (0.23±0.03). The proximal internal cross-sectional area rose from 1.46±0.04 to 5.76±1.04 mm2 as y=−3.562 + 0.352 × Age ±0.519 (R2=0.76). The internal volumetric growth from 11.89±2.49 to 119.63±4.95 mm3 generated the function y=−135.248 + 9.919 × Age ±10.478 (R2=0.86). Conclusions The growth in both length and middle external transverse diameter of the trachea follows logarithmic functions, whereas growth of both its proximal internal cross-sectional area and internal volume follow linear functions. The length and middle external transverse diameter of the trachea develop proportionally to each other. The tracheal dimensions may be helpful in the prenatal diagnosis and monitoring of tracheal malformations and obstructive anomalies of the upper respiratory tract.

The normal growth of the tracheal wall in human foetuses.

Introduction Tracheal wall thickness is a substantial indicator in various pathological changes. The present study was performed to compile normative data and formulae for the tracheal wall thickness and volume at varying gestational age. Material and methods Using anatomical dissection, digital image analysis and statistics a range of the wall thickness, proximal internal-to-external cross-sectional area ratio, and wall volume for the trachea in 73 spontaneously aborted human fetuses aged 14-25 weeks was examined. Results No significant male-female differences were found. The values of tracheal wall thickness ranged from 0.36 ±0.01 mm for the 14-week group to 1.23 ±0.17 mm for the 25-week group of gestation, according to the linear function y = –0.823 + 0.083 × age ± 0.087. The tracheal lumen rate, expressed as the proximal internal-to-external cross-sectional area ratio, decreased from 42.61 ±1.11% to 26.78 ±4.95%, according to the function y = 62.239 – 1.487 × age ±3.119. The tracheal wall volume rose from 16.28 ±4.18 mm3 in fetuses aged 14 weeks to 269.22 ±29.26 mm3 in fetuses aged 25 weeks, according to the quintic function y = 0.000052 × age4.894. Conclusions The tracheal wall parameters show no sexual dimorphism. The tracheal wall grows linearly in its length, and according to a quintic function in its volume. A relative decrease in the tracheal lumen at the expense of an increase in both the wall thickness and wall volume of the trachea is found during gestation.

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

PurposesKnowledge 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.MethodsUsing 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.ResultsWithout 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 (R2 = 0.86) for length, y = −12.042 + 4.906 × ln(age) ± 0.362 (R2 = 0.82) for width of acromial end, y = −4.210 + 2.028 × ln(age) ± 0.177 (R2 = 0.77) for width of central part, y = −4.687 + 2.364 × ln(age) ± 0.242 (R2 = 0.70) for width of sternal end, y = −51.078 + 4.174 × ln(age) ± 6.943 (R2 = 0.82) for cross-sectional area, and y = −766.948 + 281.774 × ln(age) ± 19.610 (R2 = 0.84) for volume.ConclusionsWith 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.

Ossification center of the humeral shaft in the human fetus: a CT, digital, and statistical study

PurposeThe knowledge of the development of the humeral shaft ossification center may be useful both in determining the fetal stage and maturity and for detecting congenital disorders, as well. This study was performed to quantitatively examine the humeral shaft ossification center with respect to its linear, planar, and volumetric parameters.Materials and methodUsing methods of CT, digital image analysis, and statistics, the size of the humeral shaft ossification center in 48 spontaneously aborted human fetuses aged 17–30 weeks was studied.ResultsWith no sex differences, the best-fit growth dynamics for the humeral shaft ossification center was modeled by the following functions: y = −78.568 + 34.114 × ln (age) ± 2.160 for its length, y = −12.733 + 5.654 × ln(age) ± 0.515 for its proximal transverse diameter, y = −4.750 + 2.609 × ln (age) ± 0.294 for its middle transverse diameter, y = −10.037 + 4.648 × ln (age) ± 0.560 for its distal transverse diameter, y = −146.601 + 11.237 × age ± 19.907 for its projection surface area, and y = 121.159 + 0.001 × (age)4 ± 102.944 for its volume.ConclusionsWith no sex differences, the ossification center of the humeral shaft grows logarithmically with respect to its length and transverse diameters, linearly with respect to its projection surface area, and fourth-degree polynomially with respect to its volume. The obtained morphometric data of the humeral shaft ossification center are considered normative for respective prenatal weeks and may be of relevance in both the estimation of fetal ages and the ultrasonic diagnostics of congenital 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.