ClinCorr 5- Intro to Ultrasound

Question 1

What may become the ‘stethoscope of the future’

Answer 1

handheld ultrasound (POCUS)`

Question 2

How does ultrasound work?

Answer 2

electricity activates the crystal on the head of a probe. These crystals vibrate and send sonographic waves through a liquid that propagates and reflect back. The ultrasound machine listens for these waves and translate them to an image on the screen

Question 3

What are the near field and far field?

Answer 3

near- images from superficial structures that move fast

far- images from deep structures that take longer

Question 4

What is echogenicity?

Answer 4

the ability to return an echo. Echogenicity is higher when a surface reflects an increased number of waves

Question 5

What are hyperechoic and anechoic structures?

Answer 5

herperechoic- will appear white

anechoic (e.g. blood)- will appear black

Question 6

What is the frequency of a medical ultrasound?

Answer 6

2.5-15 MHz (human hearing= 16k-20k Hz)

Question 7

What type of probe is considered high frequency? What is it used for?

Answer 7

the linear transducer probe (6-13 MHz). Used for superficial structures

used for: breasts, eyes, testicles, arteries/veins

Question 8

tight-curvilnear probe

Answer 8

2-5 MHz (low frequency= deeper penetration)

used for visualizing gallbladder, liver, kidney, bladder, abdominal aorta, abdominal fluid

Question 9

phased array probe

Answer 9

1-5 MHz

used for visualizing heart, IVC, lungs, pleura, abdomen

Question 10

Intracavity probe

Answer 10

5-8 MHz

used for ovaries, uterus, pharynx

Question 11

When imagining in the sagital plane, the pro marker should be oriented where?

Answer 11

the patient’s head (the top of the screen is always anterior (meaning superficial) and the bottom is always posterior (meaning deep), whatever side the marker is on, correpsonds to the direction of the probe marker on the body

Question 12

2D mode is aka?

Answer 12

B mode (b=brightness) aka grey mode

Question 13

What is M mode?

Answer 13

M=motion. can allow to track motion of a moving structure over time (such as a fetal heart)

Question 14

What is Doppler mode?

Answer 14

examines the characteristic and speed of tissue motion and blood flow

presented in an audible, culunar(?), or spectral display

Question 15

What is color mode?

Answer 15

aka color doppler ultrasound

shows frequency shifts coming toward or away from the transducer and translates it a color image that is superimposed over the B mode image

red= toward probe
blue= away

blue and red doesn’t necessarily mean veinous or arterial

if flow is perpendicular to the probe, no color will show

Question 16

What depth should you have on an ultrasound?

Answer 16

two finger widths behind the image of interest

Question 17

What does gain do?

Answer 17

adjusts the intensity of the signal that’s returning to the machine (increased gain= increased signal and signal is brighter)

Question 18

What does time gain compensation allow for?

Answer 18

controlling the gain at different parts of the image