Ultrasound

Question 1

What does an ultrasound do?

Answer 1

Generate images that allow for evaluation of the texture of organs and providing real-time visualization of the functional ability of organs

Question 2

Ultrasound imaging is based on the _______

Answer 2

conversion of energy

Question 3

How does the ultrasound produce the images on the screen?

Answer 3

electrical energy is applied in pulses to a probe & is then converted to sound waves by crystals w/in the probe. Those sound waves are directed into the patient. The specific rate of the sound waves depends on the direction of the wave and density of the components that the waves encounter. The waves can be absorbed, scattered, or reflected back as an echo to the transducer

Question 4

Sound waves are described by their _____ & _____

Answer 4

frequency & wavelength

Question 5

Amplitude

Answer 5

height of the waves

Question 6

Taller waves = ____ sound waves

Answer 6

louder

Question 7

Wavelength

Answer 7

Distance between each of the bands

Question 8

Frequency

Answer 8

The number of wave cycles that occur each second

Question 9

Hertz (Hz)

Answer 9

The unit of measurement of frequency

Question 10

One wave cycle per second is equal to ______ hertz

Answer 10

1

Question 11

Most procedures in diagnostic ultrasound uses frequencies with a range between

Answer 11

2-15 MHz

Question 12

Frequency and wavelength are ______ related when the speed through which the sound travels through a medium is _______

Answer 12

inversely; constant

Question 13

Greater resolution is obtained with ____ wavelengths

Answer 13

shorter (same as w/ xrays)

Question 14

Higher frequency of the shorter wavelength ______ penetrating power of the sound

Answer 14

reduces

Question 15

Anechoic

Answer 15

areas that don’t generate an echo

Question 16

How do anechoic areas appear?

Answer 16

Appear black on the final image & represent fluid-filled structures

Question 17

Hyperechoic

Answer 17

areas w/ high intensity echo

Question 18

How do hyperechoic areas appear?

Answer 18

appear very bright

Question 19

Hypoechoic

Answer 19

Little returning echo

Question 20

How do hypoechoic areas appear?

Answer 20

darker gray

Question 21

Isoechoic

Answer 21

Areas w/ returning echoes that are the same as the surrounding tissues

Question 22

What are the basic components of an ultrasound machine?

Answer 22

power source, transducer, control panel

Question 23

What is a transducer consisted of?

Answer 23

Piezoelectric crystals that are arranged in a specific configuration (array)

Question 24

What is the transducer?

Answer 24

Probe
Generates the sound waves & serves to receive the returning echoes

Question 25

How does the transducer work?

Answer 25

The piezoelectric crystals w/in the probe being to vibrate and emit sound when electrical energy is applied to the probe

Question 26

The range of frequencies the transducer can generate varies depending on what?

Answer 26

Thickness of the crystals

Question 27

The frequency the transducer can generate is based on the _____ of the crystals

Answer 27

size

Question 28

What are examples of different types of transducers?

Answer 28

sector array, linear array, curvilinear array, phased array, annular array

Question 29

What does the configuration of the array in the probe dictate?

Answer 29

the application it is used for as well as the appearance of the image on the monitor

Question 30

What does a sector array transducer produce?

Answer 30

produces a wedge or pie shaped image

Question 31

What does a linear array transducer produce?

Answer 31

A rectangular shaped image Useful when assessing blood flow

Question 32

What is the most common transducer?

Answer 32

Linear array

Question 33

What does a curvilinear array produce?

Answer 33

It is a type of linear array that is arranged into a convex curve

Question 34

What is the ideal use of microconvex versions of the curvilinear transducer?

Answer 34

most small animal patients & ideal for abdominal imaging

Question 35

What is a phased array transducer?

Answer 35

A transducer that has the crystals aligned linearly that are activated in sequence Commonly used for cardiac studies

Question 36

What are annular array transducers?

Answer 36

Transducers characterized by crystals aligned in rings Not in common use

Question 37

What does the control panel do?

Answer 37

Adjust the power, gain, time-gain compensation, brightness, contrast

Question 38

What does the power control on the control panel do?

Answer 38

alters the intensity of the sound wave (amplitude) generated by increasing the voltage to the transducer

Question 39

What happens when you apply a higher voltage to the transducer?

Answer 39

It generates sound pulses that are louder

Question 40

Louder pulses generate _________

Answer 40

louder echoes = brighter image

Question 41

What does the pulse repetition frequency control?

Answer 41

it can change the frequency or rate at which pulses are released

Question 42

Echoes from deeper tissues take ______ to return to the transducer than more superficial structures

Answer 42

longer

Question 43

The ultrasound waves lose ______ as they travel through tissues

Answer 43

amplitude (attenuated)

Question 44

What is used to determine the tissue characteristics?

Answer 44

The amplitude of the returning echo

Question 45

What does the gain control do?

Answer 45

Modify the strength of the returning echo

Question 46

What does time-gain compensation do?

Answer 46

Compensates for the difference in strength of the returning echo depending on the depth of the tissue. It also allows the ultrasound image to be modified so that the inherent brightness of more superficial structures as compared to deeper structures is minimized

Question 47

What are the three primary display modes?

Answer 47

A mode B mode M mode

Question 48

What is a mode?

Answer 48

Amplitude Mode Least commonly used Displays returning echoes as peaks that designate their intensity

Question 49

What are the primary uses of A mode?

Answer 49

ophthalmology evaluations and measurement of subcutaneous fat in production animals (swine)

Question 50

What is B mode?

Answer 50

Brightness mode Most commonly used Displays returning echoes as bright dots on the monitor w/ varying degrees of brightness corresponding to the intensity of the returning signal

Question 51

What is M mode?

Answer 51

Motion mode Creates a B mode image in motion

Question 52

What is the primary use of M mode?

Answer 52

Echocardiography

Question 53

What is a doppler ultrasound used for?

Answer 53

Evaluating blood flow The velocity and direction of the flow of blood & other fluids can be determined as well

Question 54

How does a doppler ultrasound work?

Answer 54

the sound waves generated are reflected back to the probe when they encounter cells

Question 55

What are the varying types of doppler methods?

Answer 55

color, powder, pulse wave, continuous wave

Question 56

What are the primary uses of ultrasound in large animal medicine?

Answer 56

Pregnancy diagnosis and monitoring of fetal development

Question 57

What are other uses of ultrasound in large animal medicine?

Answer 57

Useful for detection of pleural fluid in horses & is ideal for detecting injuries to tendons and ligaments in performance horses Evaluation of back fat in swine used for meat production

Question 58

What is the ultrasound used for in both large & small animal medicine?

Answer 58

Centesis and tissue biopsy

Question 59

What is an AFAST?

Answer 59

abdominal focused assessment w/ sonography for trauma It detects and scores free fluid in the peritoneal cavity, which is a common feature in abdominal trauma

Question 60

True or False: Sound waves can travel through air

Answer 60

False

Question 61

How are large animals usually evaluated w/ the ultrasound?

Answer 61

In standing position

Question 62

What from the patient can cause artifacts into the images?

Answer 62

Movement, panting, tensing of muscles, struggling

Question 63

What position should the patient be in for an aFAST?

Answer 63

right lateral recumbency

Question 64

What position should the patient be in that has respiratory or cardiac compromise for an ultrasound?

Answer 64

Standing or sternal

Question 65

What are artifacts?

Answer 65

any result that does not reflect the actual characteristics of the tissue or organ being images

Question 66

True or False: Artifacts can either aid in diagnosis or complicate or confuse diagnosis

Answer 66

True

Question 67

What are examples of different artifacts that can be present on ultrasound?

Answer 67

Comet tail, acoustic shadowing, distance enhancement, edge shadowing, slice thickness, reverberation, mirror image, side lobe