1st Trimester US (10-14 Weeks) Flashcards
(25 cards)
What do you look for in the Extremities?
Four limbs (each with three segments), Hands and feed in normal orientation
What do you look for in the placenta?
Normal size, texture, 3 vessel cord
What do you look for in the head (not face)?
Presence of head, Cranial Bones, Midline Falx, Choroid Plexus Filled Ventricles.
Diagnosis?
Omphalocele (Exomphalos) because you see the membrane, (Remember physiologic herniation resolved by 11-12 weeks)
What do you look for in the spine?
Intact overlying skin line, Vertebrae
Diagnosis?
Encephalocele
Things you never detect?
-ACC, Cerebellar hypoplasia -Duplex Kidneys, Hydronephrosis, Renal Agenesis -CCAM, Extralobar Sequestration -Duodenal Atresia, Bowel Obstruction
How do you date twins with size discrepancy?
Go by the bigger twin
Diagnosis?
Gastroschisis
Diagnosis?
Micrognathia
Diagnosis?
Lethal Skeletal Dysplasia (Frontal Bossing, chest:abdomen small)
What do you look for in the Abdomen?
Stomach in the LUQ, Bladder, Kidneys
What do you look for in abdominal wall?
Normal cord insertion, no umbilical defects
What do you look for in the heart?
Regular Cardiac Activity, Four symmetrical chambers
Things you should always detect?
Acrania, Anencephaly, Ectopia Cordis, and Encepalocele
Diagnosis?
Megacystis
Diagnosis?
Alobar Holoprosencephaly
What do you look for inside the chest (except heart)?
Symmetrical lung fields, No effusions or masses
What do you look for in the neck?
Nuchal translucency
Diagnosis?
Sacrococcygeal Teratoma (Why?, it’s in front of the spine, and Intracranial translucency makes spina bifida less likely)
Megacystis, critieria? Likely diagnoses based on size?
>7mm criteria for Megacystis.
7mm-16mm think Chromosomal
>16mm think Lower Urinary Tract Obstruction
Diagnosis?
Acrania / Exencephaly / Anencephaly Sequence
What do you look for in the face?
Eyes (w/ Lens), Nasal bone, profile/mandible, Lips Intact.
Criteria for measurement of a CRL?
1) Midline Sagittal section of whole embryo/fetus
2) As horizontal as possible
3) Fills most of the width of the screen
4) Neutral position (not flexed or extended)
5) Clear endpoints to crown and rump
6) Amniotic fluid visible between chin and chest
