Sonoanatomy Flashcards
when considering acoustic impedance if Z1 is > Z2…
no reflection
when considering acoustic impedance if Z2 > Z1 ….
reflection back to transducer
hyperechoic shows up as
bright
example: bone
hypoechoic shows up as
shades of gray ;-)
example: soft tissue
anechoic shows up as
black
example: blood
how does muscle appear?
“starry night” = heterogeneous
hyperechoic spindles contrast with hypoechoic areas of the cell
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
a. bone and muscle
7. 8 (bone) - 1.71 (muscle) = 6.09 greatest difference
what is the attenuation coefficient of muscle?
1.3-3.3 (very dense)
what is attenuation?
the decreasing intensity of a sound wave as it passes through tissue
what is the attenuation coefficient?
is the relationship of attenuation to distance
it is dependent on the tissues traversed and the ultrasound frequency
higher frequency waves are attenuated ____ than lower frequency waves
more
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
b. bone
large, dense, smooth structures
large reflection = > impedance
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
c. fat, liver, muscle, bone
from least to most: blood, fat, liver, kidney, muscle, bone
how do nerves appear in cross section?
round honeycomb structures
how do tendons differ from nerves?
they become flat and disappear when followed toward the muscle belly
how does fat appear?
hypoechoic areas with streaks of irregular hyperechoic lines
how does fascia appear?
thin linear hyperechoic structures marking tissue boundaries
adipose tissue is the ___ layer imaged
most superficial
A lines in regards to pleural tissue
sound is trapped between 2 pleura causing a delay in returning echoes = hyperechoic lines below the pleural tissue
*indicates lung fully expanded
pneumothorax
no A or B lines
no lung sliding
(visceral pleura is no longer attached to parietal pleura)
B lines in regards to pleura
“comet tail”
sound contacts highly reflective structure at an angle, sends a tail down into tissue
*seen in pathology usually
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
b. scan proximal or distal toward the muscle belly, tendon will flatten and disappear
artifacts occur because
properties of sound
tissue composition
provider technique/interpretation
commonly seen artifacts include
air artifact, shadow artifact, bayoneting, acoustic enhancement, mirror image, reverberation, ring down
