Chapter 4: Obstetric Scanning Primer Flashcards
compression of the aorta and the inferior vena cava by the gravid uterus resulting in symptoms of nausea, hypotension, lightheadedness, and syncope
aortocaval compression syndrome
pregnancy outside of the uterus
ectopic pregnancy
the amount of transmitted energy by the ultrasound beam.
mechanical index
condition where the placenta implantation is low in the uterus and will deliver before the fetus
placenta previa
the output power indication of the amount of acoustic power it takes to raise the temperature of tissue by 1 degree Celcius
thermal indices
entrapment of the umbilical cord between the presenting fetal part and the cervix
vasa previa
clockwise =
vertex— stomach to spine closest path
counterclockwise =
breech– stomach to spine closest path
A correctly filled bladder allows for imaging of the ____ and the ______.
cervix
lower placental edge
Transperineal and endovaginal imaging helps evaluate the ____ and present _____ in the second and third trimesters.
cervix
fetal anatomy
______ results in maternal feelings of nausea and dizziness due to compression of the aorta and inferior vena cava
aortocaval syndrome
_____ ultrasound in the first trimester should be used only when medically indicated.
Doppler
High ___ and ___ increase potential bioeffects to the embryo and fetus.
MI
TI
An SPTA below ____ mW/cm2 for an unfocused beam decreases the possibility of bioeffects.
100
Compression of the aorta and inferior vena cava by the gravid uterus resulting in symptoms of nausea, hypotension, lightheadedness, and syncope.
aortocaval compression syndrome
entrapment of the umbilical cord between the presenting fetal part and the cervix
vasa previa
pregnancy outside of the uterus
ectopic pregnancy
the amount of transmitted energy by the ultrasound beam.
mechanical indices
condition where the placenta implantation is low in the uterus and will deliver before the fetus
placenta previa
the output power indication of the amount of acoustic power it takes to raise the temperature of tissue by 1 degree celcius
thermal indices
A moderately distended bladder is appropriate for obstetric imaging in:
the first trimester
The inability of some females to lay supine during week 20-term of pregnancy because of a hypotensive state is known as:
aortocaval compression syndrome
A ____ transducer may provide optimal images well into the third trimester on a thin patient.
5
Endovaginal transducers aid the clinician in determining all except:
a. the presence of adnexal fluid resulting from an ectopic pregnancy
b. fluid in Morison pouch
c. gestational age in early pregnancy
d. viability in early pregnancy
b