Ch. 13 - Ultrasonography

Front 1

Ultrasonography is interactive and involves what 4 things?

Back 1

1. patient

2. doctor

3. transducer

4. sonographer

Front 2

Ultrasonography is

A) invasive

B) non-invasive

And images what kind of tissue?

Back 2

non-invasive

soft tissue

Front 3

Ultrasonography displays findings on radiographs as well as ____________ and _____________ of some organs.

Back 3

textures

dynamics

Front 4

List 4 examples of what Ultrasonography can show:

Back 4

1. heart beating

2. bowel motility

3. urine entering the bladder

4. blood flow

Front 5

As ultrasound travels through tissues it forms __________________ waves.

Back 5

longitudinal

Front 6

The two mediums used in diagnostic ultrasound are:

Back 6

tissue + fluids

Front 7

Can ultrasound travel through bone?

Back 7

No - bone is an acoustic barrier

(Bone is too dense)

Front 8

Name another acoustic barrier.

Back 8

Air - sound saves just bounce back

Front 9

Frequency of sound waves:

Ultrasound utilizes sound waves of very ____________ frequency.

(What is the range?

Back 9

high frequency

range = 2 - 10 MHz (megahertz) or higher

Front 10

Sound with a frequency of __________________ Hz or higher is called ultrasound.

Why?

Back 10

20,000 or higher Hz

Because it is beyond the frequency range of the human ear

Front 11

1 megahertz = ______________________ Hz

Back 11

1,000,000 Hz

(one million)

Front 12

On a visual graph of sound waves,

Frequency s the...

Back 12

number of complete variations in 1 second

Front 13

If 5 cycles occur in 1 second, then it is written as:

Back 13

5 cycle/sec

or

5 Hz

Front 14

If 5 cycles occurred in 1 MICROsecond (5 million cycles) =

Back 14

5 MHz

Front 15

The power of the sound waves depends on what things? (2)

Back 15

1. transducer

2. MHz

(sort of like kVp)

Front 16

The thicker the tissue, ....

Back 16

the more penetrating power (MHz) you need

Front 17

Transducers convert...

Back 17

one type of energy into another

Front 18

Ultrasound transducers convert ____________ energy into ____________ ultrasound energy

Back 18

electric

into

ultrasound

Front 19

What kind of crystal is in a transducer and what does it do / how does it work?

Back 19

Piezoelectric crystal

Emits sound when an electric impulse is applied

Front 20

The sound waves reflect back to the __________________ as echoes and are analyzed by the computer to produce a __________-scale image.

Back 20

transducer

grayscale

Front 21

Transducers come in different ___________.

What two things will determine which transducer you use?

Back 21

MHz

size of patient; study being done

Front 22

Transducers come in two different configurations:

Back 22

1. Mechanical

2. Arrays

Front 23

Mechanical transducers produce a ____________- time image that is shaped like_________________.

Mechanical transducers are used for what type of study?

Back 23

real-time image

pie wedge / sector

Abdominal

Front 24

Mechanical transducers sweep the beam, ______________, and have 1 or more crystals.

The "NEAR" field is....

Back 24

oscillate

closest to the transducer itself

Front 25

Arrays:

What are the 4 tips of arrays?

Back 25

1. linear

2. curvilinear

3. phased

4. anular

(the shape of the end of the transducer + the way it uses the beams / waves)

Front 26

Which one is most commonly used for abdominal ultrasounds?

Back 26

curvilinear

Front 27

What type of array offers an elongated view with a wider field?

Back 27

linear

Front 28

Which transducer array is used for echocardiograms?

Back 28

Phased

Front 29

Which transducer array is set for tendons on horses?

Back 29

Linear array

Front 30

Which transducer do I use?

1. Small dogs + cats (< 10kg) =

2. Medium size dogs =

3. Large breeds =

4. Ophthalmic studies =

Back 30

1. 7.5 or 10 MHz

2. 5.0 MHz

3. 5.0 - 3.0 MHz

4. 7.5 or 10 MHz (same as small dog / cat)

Front 31

True or false:

You may have to use multiple transducers in some cases for a complete study.

Back 31

TRUE

Front 32

Acoustic Impedence - what is it?

Back 32

The ability of living tissue being imaged to resist or impede the transmission of sound.

Front 33

Acoustic Impedence:

Varies slightly among tissue, depending on the _____________ and the _____________ of tissue.

Back 33

density

elasticity

Front 34

Acoustic Impedence allows us to differentiate between ________.

Back 34

organs

Front 35

Acoustic Impedence interfaces between:

1) soft tissue & ___________

2) soft tissue & ___________

vary greatly in acoustic impedence, resulting in _______________ of almost all sound waves

Back 35

1. air

2. bone

reflection

Front 36

Another way to say this is that:

Back 36

Bone and air are barriers to ultrasound waves

(The waves cannot penetrate through)

Front 37

Attenuation =

Back 37

weakening

Front 38

Attenuation refers to the weakening or decreasing intensity of sound waves as they...

Back 38

travel through tissue

Front 39

Attenuation occurs through ____________ and ________________.

Back 39

1. scatter

2. absorption

Front 40

Attenuation:

Scatter occurs when:

Back 40

sound reflects in may directions off different tissue interfaces

Front 41

Attenuation:

Absorption occurs due to the _____________ __________ from the sound passing through the tissues, creating heat.

Back 41

molecular friction

Front 42

Since sound that travels in and out of tissue is subject to attenuation, this limits the ____________ of tissue that can be imaged.

Back 42

depth

Front 43

The amount of attenuation depends on the _______________.

Back 43

frequency of the transducer

(penetrating power)

Front 44

Lower frequency transducers offer:

more ____________

less ____________.

Back 44

more depth

less resolution

2.5 - 5 MHz

Front 45

Higher frequency transducers offer:

more __________

less ____________.

Back 45

more resolution

less depth

7.5 - 13 MHz

Front 46

Modes of Image Display:

What are the 3 modes:

Back 46

A - Mode (amplitude mode)

B - Mode (brightness mode)

M - Mode (motion mode)

Front 47

A - Mode

Returned echoes are displayed as a series of __________ on a graph.

Back 47

peaks

Front 48

A - Mode (amplitude) is used in __________________ to measure...

Back 48

ophthalmology

to measure length & depth of eye

Front 49

B - Mode (brightness) uses ___________ or dots on a screen to develop an image on the screen.

B - Mode offers a 2D or 3D "______________ ___________" that is continually updated.

Back 49

pixels

anatomic slice

Front 50

M - Mode (motion) offers :

Back 50

continuous display of a thin slice of an organ over time

Front 51

M-Mode is mainly used for _____________.

Back 51

echocardiography

(to assess the size of the heart chambers and motion of the cardiac valves and wall)

Front 52

Terminology:

Echoic (echogenic):

Appearance on screen =

Back 52

most sound reflected back to transducer.

white (brighter) on screen

Front 53

Terminology:

Sonolucent:

Appearance on screen =

Back 53

Most sound transmitted to deeper tissues, few echoes reflected back

dark on screen

Front 54

Terminology:

Anechoic:

Appearance on screen =

Back 54

ALL sound transmitted to deeper tissue. No sound reflected back.

Black on screen

Front 55

What type of organs / structures are typically anechoic?

Back 55

fluid-filled structures

ex. full bladder

Front 56

Hyper echoic:

Appearance =

Back 56

Tissues reflect more sound back to transducer than the surround tissues.

Brighter than surrounding tissues

Front 57

Hypo echoic:

Appearance =

Back 57

Tissues that reflect less sound back to the transducer than the surrounding tissues.

Darker than surrounding tissues

Front 58

Isoechoic:

Back 58

Tissues that appear to have the same echo texture on the screens as the surround tissues.

Front 59

Miscellaneous Anatomy:

Right kidney - compare it to ___________

Left kidney - compare it to ___________

Back 59

Right - LIVER

Left - SPLEEN

Front 60

Views:

Short Axis = ____________

Long Axis = _____________

Back 60

Transverse

Saggital

Front 61

Instrumentation:

Allows for what 2 controls to be manipulated (that affect overall brightness)

Back 61

1. Gain (overall)

2. Power (output)

Front 62

Instrumentation:

Depth - what does this control?

Back 62

amount of tissue being displayed on the screen

Front 63

Instrumentation:

What are 2 ways to compensate for attenuation?

Back 63

1. Increase the gain (increases sensitivity of the transducer to receiving the returning echoes)

(think of a hearing aid, which increases sensitivity to sound)

2. Power controls the intensity of the sound generated.

Front 64

So basically - to compensate for attenuation:

Back 64

1. increase sensitivity of transducer to sound

2. increase intensity of the sound (power)

Front 65

Time Gain Compensation (TGC):

1. This allows...

Back 65

1. echo display of equal brightness, regardless of depth

Front 66

Time Gain Compensation (TGC):

Superficial tissues (near field) are _____________ in intensity

Back 66

reduced

Front 67

Time Gain Compensation (TGC):

Deeper tissues (far field) need a boost in...

Back 67

echo brightness

Front 68

Time Gain Compensation (TGC):

Adjustments need to be made to be able to view...

Back 68

Both near and far fields

Front 69

Time Gain Compensation (TGC):

You may also have to use a different MHz transducer depending on how _____________ or ________ the structure you are trying to visualize is.

Back 69

superficial

deep

Front 70

Artifacts:

Back 70

Acoustic shadowing

a) distant enhancement

b) reverberation

c) mirror image

d) refraction

Front 71

Acoustic shadowing:

What happens to the sound?

Back 71

Attenuated at acoustic interface

This prevents sound from being transmitted to deeper tissue

Front 72

In acoustic shadowing there is a _______________________ of returning echoes.

Back 72

absence of / lower amount of

Front 73

Structures that cause acoustic shadowing (4)

Back 73

1. bone

2. calculus

3. mineralization

4. fat

ex. gall stone shadow

Front 74

Distant Enhancement:

Not a shadow - it's a brightness.

Occurs when sound beams traverses what type of structures?

Back 74

cystic (any organ that can get a cyst)

Front 75

With Distant Enhancement, tissue deep toward the cystic structure will appear _______________ than surrounding tissue

Back 75

brighter

Ex. may see something that looks like a hyper echoic nodule, but really isn't)

Front 76

Reverberation:

Sound is reflected off a highly reflective interface.

Name 2 examples:

Back 76

1. soft tissue to air

2. soft tissue to bone

Front 77

Mirror Image:

Creates an illusion - ex. liver appearing on thoracic side

This occurs in areas with what type of surfaces?

Ex.?

Back 77

highly reflective surfaces

ex. diaphragm

Front 78

Refraction:

Produces when transmitted sound is refracted at an interface between...

Back 78

2 tissues of different acoustic impedence

Front 79

Refraction:

The object may appear to slightly shift from real position, creating a _______.

Back 79

shadow

Front 80

With ultrasonography you have to know what 3 things?

Back 80

1. anatomy

2. machine

3. artifacts

Front 81

When doing an ultrasound:

1. lube goes...

2. black dot faces...

3. For abdomen, start at...

Back 81

1. directly onto patient, not transducer

2. up

3. right under xiphoid process