<unk>  (NT procedure) is performed between 11 and 14 weeks of gestation, because the accuracy is best in this period. The scan is obtained with the fetus in sagittal section and a neutral position of the fetal head (neither hyperflexed nor extended, either of which can influence the<unk>  translucency thickness). The fetal image is enlarged to fill 75% of the screen, and the maximum thickness is measured, from leading edge to leading edge. It is important to distinguish the<unk>  lucency from the underlying amniotic membrane. Normal thickness depends on the crown-rump length (CRL) of the fetus. Among those fetuses whose<unk>  translucency exceeds the normal values, there is a relatively high risk of significant abnormality.
Nuchal scan
Birmingham gauge
MRI Robot
ShuntCheck
SNOMED CT
EConsult
Scan
VistA Imaging