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Atlas of Human Body Ultrasound Scanning_ Methods and Diagnostic Applications ( PDFDrive ).pdf
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484

YQ. Zhou et al.

 

 

1.5.1\ Scanning Method

The patient is maintained in the supine position, with properly filled bladder and exposure of the lower abdomen. The probe should be placed longitudinally on the medioventral line above the pubic symphysis.

1.5.2\ Section Structures

Sagittal section of the uterus and coronal section of the fetus with the fetal head, thorax, abdomen, and upper limbs are shown.

1.5.3\ Measuring Method

Fetal length and size of the yolk sac could be measured in this section.

1.5.4\ Clinical Significance

The fetal shape could be recognized at the end of 8 weeks of gestation. Fetal heart beats and rhythm are also observed. The placenta begins to form at 8 weeks of gestation, shown as a half-moon-­ shaped homogeneous hyperechoic region.

13  Normal Pregnancy

485

 

 

1.6\ Transverse Scanning

of the Gestation at 9 Weeks’

Pregnancy

Fig. 13.6  Transverse section of the fetal brain at 9 weeks of gestation, the skull and the medioventral line are shown. FH fetal head

FH

486

YQ. Zhou et al.

 

 

1.6.1\ Scanning Method

The patient is maintained in the supine position, with properly filled bladder and exposure of the lower abdomen. The probe is placed longitudinally on the medioventral line above the pubic symphysis at first. And then, after detecting the long axis view of the fetus, the probe should be turned 90° to find out the transverse sections of fetal brain.

1.6.2\ Section Structures

The ring of fetal skull and the brain midline is shown.

1.6.3\ Measuring Method

Biparietal diameter could be measured in the transverse section of the thalamus.

1.6.4\ Clinical Significance

To investigate if there is a skull and if it’s intact, in order to exclude skull malformations such as anencephalus and incomplete skull defects.

13  Normal Pregnancy

487

 

 

1.7\ Longitudinal Scanning

of the Fetus at 10–12 Weeks

of Gestation

Fig. 13.7  Sagittal section of the fetal trunk at 10–12 weeks of gestation, the fetal head, fetal abdomen, fetal limbs, and the yolk sac are shown. FH fetal head, FAb fetal abdomen, FLb fetal limb, YS yolk sac

FL

FH

YS

FB

1.7.1\ Scanning Method

The patient is maintained in the supine position, with properly filled bladder and exposure of the lower abdomen. The probe is placed longitudinally on the medioventral line above the pubic symphysis.

1.7.2\ Section Structures

In sagittal section of the uterus, a fully formed fetus can be detected after 10 weeks of gestation; the fetal head, limbs, and spine can be recognized also.

1.7.3\ Measuring Method

The crown-rump length (CRL) could be measured in middle sagittal section of fetus; M-mode ultrasound could be applied to detect fetal heart beats. CRL is named sitting height after birth.

1.7.4\ Clinical Significance

According to the parameters detected above, viability and development of the embryo are estimated. CRL is used to determine fetal age and to estimate if the fetal age is equal to gestational weeks.