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Atlas of Human Body Ultrasound Scanning_ Methods and Diagnostic Applications ( PDFDrive ).pdf
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13  Normal Pregnancy

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4.6.1\ Scanning Method

The probe is put on the fetal forehead, moved forward and down to find out the coronary section of the fetal face, and then the probe is rotated to find out the transverse section of the palatal arch and sagittal section of the fetal face.

4.6.2\ Section Structures

Bilateral orbits, two nostrils, and upper lip of the mouth should be shown in coronary section of the fatal face, and the crystalline lens in the orbit is shown as a little circle at the inner frontal side of the eyeball (Fig. 13.18). Two erupted teeth are shown in the transverse section of palatal arch (Fig. 13.19). The nasal bone is shown like a stub in the median sagittal section (Fig. 13.20).

4.6.3\ Measuring Method

Nasal bone length is measured as the distance between the superior margin and the inferior margin of nasal bone.

4.6.4\ Clinical Significance

Nasal bone length is one of the soft markers of chromosomal abnormalities and is also valuable in excluding unilateral or bilateral absence of nasal bone.

4.6.5\ Normal Reference Values

Nasal bone length changes with the growth of gestational weeks.

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4.7\ Longitudinal Scanning

of Fetal Neck

Fig. 13.21  Sagittal section of the fetal neck, fetal head and spine are also shown. AF amniotic fluid, FB fetal body, FH fetal head, LEG leg

AF

FB

LEG

YQ. Zhou et al.

FH

13  Normal Pregnancy

509

 

 

4.8\ Longitudinal Scanning

of Fetal Neck with Cord

Impression

Fig. 13.22  Sagittal section of the fetal neck with a W-shaped impression, which represents cord around neck two loops. The arrows refer to umbilical cord impression shown as W-shaped depression

510

YQ. Zhou et al.

 

 

4.9\ Color Doppler Flow Image

of the Cord Around Neck in

Sagittal Section of the Fetal

Neck

Fig. 13.23  Sagittal section of the fetal neck. Color Doppler flow signals are shown also. The colorized structure in the color sampling frame is the cord around neck

Blood flow signal of the umbilical cord

4.9.1\ Scanning Method

The probe is moved down to find the sagittal section of the fetal neck after detecting the head.

4.9.2\ Section Structures

Part of the fetal head, nuchal skin, and sagittal section of the cervical spine should be shown.

4.9.3\ Clinical Significance

In normal second and third trimester, fetal nuchal skin is shown smoothly on the surface. There is

an anechoic region between the neck and the uterine wall, which is clear in image, referring to amniotic fluid (Fig. 13.21). Umbilical cord impression is shown as U-shaped or W-shaped depression in sagittal plane when there was cord around neck (Fig. 13.22). Signals of the umbilical vessels around the neck could be detected in transverse section of the neck, when an anechoic impression found in the neck in sagittal plane and suspicious of cord around the neck (Fig. 13.23).