M103 T1 ultrasound

Question 1

How does ultrasound work?

Answer 1

by transmitting high-frequency sound waves through tissue

Question 2

What does a transducer do?

Answer 2

emits sound-waves

Question 3

What causes echoes?

Answer 3

sudden changes in tissue density or at a tissue interface (e.g. between muscle and bone)

Question 4

How are echoes used to make an image?

Answer 4

echoes are detected by a transducer

the delay and intensity of these echoes can be used to construct an image

Question 5

What colour does fluid and air appear on the xray image?

Answer 5

f & a - black

Question 6

What colour do boney surfaces appear on the image?

Answer 6

bright

Question 7

What colour do muscles and the viscera appear on xrays?

Answer 7

a mid-grey appearance

Question 8

What does an orientation marker on the probe indicate?

Answer 8

which way the probe should be held

Question 9

Where does an orientation marker on the probe usually point to?

Answer 9

the right side of the patient

Question 10

During cardiac ultrasound where does an orientation marker on the probe point to?

Answer 10

the left side of the patient

Question 11

Which three pathologies are Point of Care Ultrasounds used to assess?

Answer 11

Pulmonary oedema
Pleural effusion
Pneumothorax

Question 12

What are the three main types of transducers? (CLiP)

Answer 12

curvilinear array
linear array
phased array

Question 13

What are the pros and cons of using a linear array when taking an ultrasound?

Answer 13

provides a high resolution image
only up to about three cm of depth+
not able to take images of the heart

Question 14

When are linear arrays used to take an ultrasound?

Answer 14

when looking at vascular or musculoskeletal structures

Question 15

What do curvilinear and phased arrays have in common?

Answer 15

can produce images of deeper structures

have sector fields of view

Question 16

What are the pros and cons of using a phase array when taking an ultrasound?

Answer 16

has a larger coverage area than single-probe methods - allows technicians to scan more at once, reducing the amount of time needed for inspections
expensive
operation and data interpretation are more difficult
can be greater difficulty in achieving good ultrasonic coupling due to the larger probe dimensions

Question 17

When might phase array be used instead of curvilinear array and why?

Answer 17

phase array has a small footprint - the area of the ultrasound probe that would actually be contacting the skin, so can get in those intercostal spaces
curvilinear images will have more interference from the ribs than when using phase

Question 18

Where might curvilinear array be used?

Answer 18

abdomen

thorax

Question 19

Where might linear array be used?

Answer 19

pectoralis muscles

Question 20

What are the borders of the safe triangle?

Answer 20

lateral edge of the pectoralis major - LPMA
lateral border of the latissimus dorsi - LLD
inferiorly - 5is
superiorly - base of the axilla

Question 21

How do you find the base of the axilla?

Answer 21

join the lines between the pectoralis major and the latissimus dorsi