quiz 2 Flashcards
Lateral ventricle width is normal up to ____ mm.
10
For long bone measurements of the fetus, calipers are placed at the?
bone-cartilage interface.
The circular structure visualized between 4 and 10 weeks that supplies nutrition to the developing embryo is the ___________.
yolk sac
As a trimester progresses, the crown rump length and amniotic sac diameter increase ___ mm a day.
1
A yolk sac is considered abnormal if it is larger than ____ mm.
6
If an embryo is not visualized within the gestational sac, the GA in weeks can be determined by measuring the mean sac diameter and adding ____ to it.
3 mm
Placenta previa can be ruled out if the placenta is _______ cm from the internal os.
2
Normal gut herniation should not be seen after the ______ GA week.
twelfth
The abdominal circumference (AC) is measured through a single plane of section that demonstrates where the..?
umbilical vein branches and the left and right portal veins are continuous with one another.
The BPD can be measured
through any plane of section that demonstrates a symmetrical view of the short axes of the third ventricle and thalami.
Male gender can be established from the early second trimester by identifying the..?
scrotum
When the umbilical cord enters the fetus…?
the umbilical vein courses cephalad to join portal circulation and the umbilical arteries run along each side of the urinary bladder.
Between the twelfth and sixteenth gestational weeks, the amniotic cavity has enlarged enough to
obliterate the chorionic cavity
A tail-like appendage is often identified at the site of the embryo’s rump. With development it
regresses
When the yolk sac, embryonic disk, and developing amniotic membrane are visualized together it is described as the
double bleb sign.
An intrauterine pregnancy can be confirmed before visualization of the yolk sac by identifying the
double sac sign
The intradecidual sign
describes an early intrauterine pregnancy adjacent to the endometrial cavity.
when scanning the fetus, the first thing to do is…?
determine fetal presentation
the sonographic landmark for locating early cardiac activity is the
yolk sac
using a 28-day menstrual cycle, most radiologists and obstetricians define the first trimester as the
12 weeks beginning with the first day of the last normal menstrual period
Landmarks for BPD/HC measurement;
thalami_,Falx cerebri, CSP (cavum septum pellucidum) and 3rd ventricle
BPD should be measured
outer to inner
HC should be measured ?
outer to outer
Landmark for AC
Rounded abdomen Stomach bubble, 3 dots of spine and junction of umbilical vein with LPV.
