The transverse MRIs, sectional anatomy and Nissl-stained slices of the fetal adrenal gland of different GA.

<p>A and B are the transverse MRIs of the fetal adrenal gland of 24 and 36 weeks GA. C and E are the sectional anatomy and the Nissl-stained section of the right adrenal gland in A. D and F are the sectional anatomy and the Nissl-stained section of the left adrenal gland in B. The zona fasciculata, zona reticularis and the medulla of the fetal adrenal gland are described with high signal intensities, and the zona glomerulosa of the cortex is low signal intensity on T₂ weighted MRI. There are good consistencies in delineating the fetal adrenal gland between the MRI and the transverse sections. The zona glomerulosa of the cortex, containing more cells, becomes thicker as GA increases (arrowheads in A–F). The bars in E, F represent 500 µm.</p

The 3D visualization models of the fetal adrenal gland of different GA.

<p>They are 23 (A), 27(B), 32(C), and 36 (D) weeks GA, respectively. The fetal adrenal gland appears as a pyramidal or half-moon shape, and almost remains the same during 23–40 weeks GA. The medial surface is flat. The groove on the lateral surface becomes shallower as GA increases. The bar in each figure represents 1 centimeter.</p

Fetal Adrenal Gland in the Second Half of Gestation: Morphometrical Assessment with 3.0T Post-Mortem MRI

<div><p>Background</p><p>The morphometry of fetal adrenal gland is rarely described with MRI of high magnetic field. The purpose of this study is to assess the normal fetal adrenal gland length (AL), width (AW), height (AH), surface area (AS) and volume (AV) in the second half of gestation with 3.0T post-mortem MRI.</p><p>Methods and Findings</p><p>Fifty-two fetal specimens of 23–40 weeks gestational age (GA) were scanned by 3.0T MRI. Morphological changes and quantitative measurements of the fetal adrenal gland were analyzed. Asymmetry and sexual dimorphism were also obtained. The shape of the fetal adrenal gland did not change substantially from 23 to 40 weeks GA. The bilateral adrenal glands appeared as a ‘Y’, pyramidal or half-moon shape after reconstruction. There was a highly linear correlation between AL, AW, AH, AS, AV and GA. AW, AH, AS and AV were larger for the left adrenal gland than the right. No sexual dimorphism was found.</p><p>Conclusions</p><p>Our data delineated the normal fetal adrenal gland during the second half of gestation, and can serve as a useful precise reference for anatomy or in vivo fetus.</p></div

The gross anatomy (A), 3D visualization model and linear measurements of the fetal adrenal gland of 32 weeks GA (B and C).

<p>The AL, AW and AH are the longest length of the three axes of fetal adrenal gland (B, C). The fetal adrenal gland is lying and circling upper pole of the kidney, and is relatively a large organ (A). There are good consistencies in delineating the fetal adrenal gland between gross anatomy and the reconstructed 3D model (arrowheads in A and B).</p

GA (weeks) dispositions and numbers of the chosen specimens (n = 52).

<p>GA (weeks) dispositions and numbers of the chosen specimens (n = 52).</p

The statistical results between all the measurements and GA.

<p>They are the scattergrams, best-fit equations and correlation coefficients (R²) of AH (A, F), AL (B, G), AW (C, H), AS (D, I), AV (E, J) and GA. All the measurements linearly increase with GA. Each symbol represents one single fetus. The blue points represent measurements of the left fetal adrenal gland and the red points represent the right.</p

Manual segmentation of the fetal adrenal gland of 36 weeks GA on the T₂ -weighted MRIs.

<p>A, B and C are the transverse, sagittal, and coronal MRIs. Different colors are filled after segmentation (D–F). The fetal adrenal gland is comparatively large, and the inner part is described with high signal intensities and the outer part is low.</p

The original measurements of the left/right adrenal glands (n = 52).

<p>GA (weeks); AH, AL, AW (cm); AS (cm²); AV (cm³).</p

Additional file 1 of Clinical characteristics and mortality predictors among very old patients with pulmonary thromboembolism: a multicenter study report

Additional file 1: Supplement. Echocardiography in very old patients with PTE