Mateusz Badura

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.

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 (Students t-test, regression analysis), we measured the base, 2 sides, area and interior angles of Petits 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.

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 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.

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.