Doppler Applications in OBGYN

Question 1

Which vessels supply blood to the pelvic organs?*

Answer 1

internal iliac arteries/hypogastric arteries

Question 2

The doppler of which arteries help predict IUGR?*

Answer 2

Umbilical artery, middle cerebral artery, uterine artery

Question 3

The diastolic notch is best described as?*

Answer 3

Early diastolic flow reduction

Question 4

Diastolic notch is a prognostic value only after?

Answer 4

24 wks GA

Question 5

What is the Doppler criterion that provides the best indicator of diastolic runoff into distal vascular bed?*

Answer 5

Pulsatility index

Question 6

During menses, what happens to the spiral arteries and endo?

Answer 6

constrict; sheds

Question 7

Impedence and resistance ______ during the periovulatory and luteal phase

Answer 7

decrease

Question 8

Doppler ultrasound is standard in the evaluation of?

Answer 8

high-risk pregnancies

Question 9

What is an example of the audible acoustic Doppler effect?

Answer 9

siren of an ambulance as it moves toward and away

Question 10

Pitch (frequency) is higher ______ the receiver

Answer 10

towards

Question 11

Pitch (frequency) is lower ______
from the receiver

Answer 11

away

Question 12

What happens when high frequency sound interacts with RBCs?

Answer 12

Rayleigh scattering

Question 13

Color Doppler allows you to evaluate?

Answer 13

Direction and velocity of blood flow

Question 14

The Doppler frequency shift is _____ when it is away from the transducer

Answer 14

negative

Question 15

The Doppler frequency shift is _____ when it is toward the transducer

Answer 15

positive

Question 16

What are the variables of the Doppler formula that are under sonographer control?

Answer 16

incident frequency (selected Probe) and Doppler angle (Probe position and steering)

Question 17

What are the variables of the Doppler formula that are not under sonographer control?

Answer 17

Speed of sound (medium) and velocity of moving RBCs

Question 18

How can you correct aliasing?

Answer 18

reduce depth (decrease baseline) or increase PRF (transducer frequency)

Question 19

Aliasing occurs when what limit is exceeded?

Answer 19

Nyquist limit

Question 20

The Doppler angles should be less than?

Answer 20

60 degrees

Question 21

What happens when the Doppler angle is at 0 degrees?

Answer 21

reliability of the Doppler signal increases

Question 22

What happens when the Doppler angle is at 90 degrees?

Answer 22

reliability of the velocity measurement is unreliable

Question 23

What are the hemodynamic parameters assessed with doppler ultrasound?*

Answer 23

presence of flow, pulsatility of flow, direction of flow

Question 24

How does arterial flow appear?

Answer 24

pulsatile highs and lows

Question 25

How does venous flow appear?

Answer 25

slow and phasic

Question 26

True or False: Doppler can differentiate normal vs abnormal

Answer 26

false

Question 27

Ovarian torsion is more common in ovaries with?

Answer 27

a mass

Question 28

How does ovarian torsion appear sonographically?*

Answer 28

**whirlpool sign** enlarged, free fluid, absent flow, mass common

Question 29

A ring of fire sign can indicate?

Answer 29

ectopic pregnancy or corpus luteum cyst

Question 30

GTD demonstrates what flow?*

Answer 30

high amplitude and low resistance

Question 31

RPOC demonstrates what flow?

Answer 31

enhanced blood flow

Question 32

Where can the uterine artery be found?*

Answer 32

at the level of the cervix

Question 33

Estrogen allows _____ resistance blood flow in the uterus

Answer 33

low

Question 34

Progesterone allows ______ resistance blood flow in the uterus

Answer 34

high

Question 35

A postmenopausal uterus demonstrates ______ resistance bloow flow

Answer 35

high

Question 36

A uterus with hormone replacement therapy (HRT) demonstrates _______ resistance blood flow

Answer 36

low

Question 37

A diastolic notch can predict?

Answer 37

poor fetal outcome (more resistance, compromised flow)

Question 38

As pregnancy progresses, the umbilical artery resistance should?*

Answer 38

decrease

Question 39

The middle cerebral artery is dopplered to assess?

Answer 39

IUGR and anemia

Question 40

What is brain sparing? What results from it?

Answer 40

blood shunts to brain when there is inadequate flow; small abdomen

Question 41

Fetal anemia can be shown by?

Answer 41

high peak systolic velocity

Question 42

What is supine hypotensive syndrome (SHS)?

Answer 42

IVC is compressed and mom cannot breathe properly

Question 43

How can you correct SHS?

Answer 43

Roll mom onto her left side

Question 44

How do flow patterns change as the uterus cycles towards menstruation?*

Answer 44

resistance decreases