Sonoanatomy

Question 1

when considering acoustic impedance if Z1 is > Z2…

Answer 1

no reflection

Question 2

when considering acoustic impedance if Z2 > Z1 ….

Answer 2

reflection back to transducer

Question 3

hyperechoic shows up as

Answer 3

bright

example: bone

Question 4

hypoechoic shows up as

Answer 4

shades of gray ;-)

example: soft tissue

Question 5

anechoic shows up as

Answer 5

black

example: blood

Question 6

how does muscle appear?

Answer 6

“starry night” = heterogeneous

hyperechoic spindles contrast with hypoechoic areas of the cell

Question 7

Which of the following situations would create the brightest echo?

a. bone and muscle
b. kidney and muscle
c. blood and muscle
d. fat and muscle

Answer 7

a. bone and muscle

7. 8 (bone) - 1.71 (muscle) = 6.09 greatest difference

Question 8

what is the attenuation coefficient of muscle?

Answer 8

1.3-3.3 (very dense)

Question 9

what is attenuation?

Answer 9

the decreasing intensity of a sound wave as it passes through tissue

Question 10

what is the attenuation coefficient?

Answer 10

is the relationship of attenuation to distance

it is dependent on the tissues traversed and the ultrasound frequency

Question 11

higher frequency waves are attenuated ____ than lower frequency waves

Answer 11

more

Question 12

specular reflection is most often associated with which of the following tissues?

a. blood
b. bone
c. muscle
d. pleura
e. none of the above

Answer 12

b. bone
large, dense, smooth structures
large reflection = > impedance

Question 13

Sound attenuates as it passes through tissue. Select the correct order of tissue that attenuates from the least to the most

a. liver, fat, muscle, blood
b. bone, muscle, liver, fat
c. fat, liver, muscle, bone
d. fat, muscle, liver, bone
e. kidney, muscle, liver, bone

Answer 13

c. fat, liver, muscle, bone

from least to most: blood, fat, liver, kidney, muscle, bone

Question 14

how do nerves appear in cross section?

Answer 14

round honeycomb structures

Question 15

how do tendons differ from nerves?

Answer 15

they become flat and disappear when followed toward the muscle belly

Question 16

how does fat appear?

Answer 16

hypoechoic areas with streaks of irregular hyperechoic lines

Question 17

how does fascia appear?

Answer 17

thin linear hyperechoic structures marking tissue boundaries

Question 18

adipose tissue is the ___ layer imaged

Answer 18

most superficial

Question 19

A lines in regards to pleural tissue

Answer 19

sound is trapped between 2 pleura causing a delay in returning echoes = hyperechoic lines below the pleural tissue
*indicates lung fully expanded

Question 20

pneumothorax

Answer 20

no A or B lines
no lung sliding
(visceral pleura is no longer attached to parietal pleura)

Question 21

B lines in regards to pleura

Answer 21

“comet tail”
sound contacts highly reflective structure at an angle, sends a tail down into tissue
*seen in pathology usually

Question 22

nerves and tendons appear similar when imaged on ultrasound. How can you differentiate them?

a. apply color doppler to identify flow
b. scan proximal or distal toward the muscle belly, tendons will become flat and disappear
c. observe for reverberation artifact from tendon movement with muscle contraction
d. all of the above are correct

Answer 22

b. scan proximal or distal toward the muscle belly, tendon will flatten and disappear

Question 23

artifacts occur because

Answer 23

properties of sound
tissue composition
provider technique/interpretation

Question 24

commonly seen artifacts include

Answer 24

air artifact, shadow artifact, bayoneting, acoustic enhancement, mirror image, reverberation, ring down

Question 25

ultrasound systems operate under several basic assumptions:

Answer 25

sound travels at exactly 1540 m/s
sound waves travel in a straight line
sound travels directly to the reflector and back
echo intensity corresponds directly to reflector strength

Question 26

air artifact occurs

Answer 26

when imaging smaller structures

*add gel and apply even pressure to correct

Question 27

shadow artifact is

Answer 27

when a sound beam contacts a strong reflector, the amplitude of the beam distal to structure is greatly diminished

Question 28

bayoneting of a needle

Answer 28

occurs when it passes through adjacent tissues of different densities

Question 29

reverberation

Answer 29

when sound reflects off two strong specular reflections separated by a thin layer of air or fluid, an illusion of multiple structures is displayed

Question 30

mirror image

Answer 30

sound trapped between two highly reflective surfaces, cause delay in returning image