Ultrasonography during pregnancy

Ultrasonography during pregnancy

CRL(1기:14wks이전) BPD(2기:14-26wks)

HC(3기)AC(3기)

* 1st trimester : start ~ 12wks

- Gastational sac : GA 6wks (TVUSG : GA 5wks) -> 1st 소견

- Blightend ovum

- Nuchal translucency : > 6mm일 경우 Positive -> 주로 1st trimester 말기(11-14wks)

주로 heart abnormaly, congenital diaphragmatic hernia, gastroschisis와 연관
fetus의 목이 신전되어 있을 경우 과다하게 측정될 수 있으므로 꼭 중립에 위치 시 측정한다.

* 2nd & 3rd trimester

- Anencephaly : 주로 2nd trimester(빠르면 1st trimester에도 가능)

이마뼈가 없어서 안구가 돌출되어 보이는 frog eye appearance 가 특징

- Meningomyelocele : 주로 14-15wks경 관찰가능

1. Lemon sign : frontal area가 lemon 모양으로 돌출
Lemon sign. Axial USG image of the fetal head at the level of the biparietal diameter (A) shows inward concavity of both frontal bones (arrows) instead of the normally seen convexity. This gives the head the appearance of a lemon. Sagittal USG image of the fetus (B) shows a meningomyelocele (thick arrow) in the lumbar region

2. Cisterna magna의 폐쇄
3. 소뇌가 정상적으로 관찰되지 않는다.
4. 소뇌의 만곡이상(banana sign)

5. 뇌실확장

Spina bifida is a congenital disorder (birth defect) in which the backbone and spinal canal do not close before birth. In severe cases, this can result in the spinal cord and its covering membranes protruding out of an affected infant's back. Spina bifida may also be nearly inconsequential, or may be reparable through surgery.