MODULE 1 Flashcards
(110 cards)
1
Q
Successive oscillation accompanied by a transfer of energy that travels through a medium or vacuum
A
Waves
2
Q
A mechanical wave that needs a medium in order to be transmitted
A
Soundwaves
3
Q
Reduction in pressure
Low density
A
Rarefraction
4
Q
Increase in pressure
High density
A
Compression
5
Q
2 types of propagation
A
Rarefraction
Compression
6
Q
Transmittal to distant regions
One to another molecules in motion
A
Propagation
7
Q
2 types of waves
A
Mechanical Wave
Electromagnetic Wave
8
Q
Needs a medium to be transmitted
A
Mechanical Wave
9
Q
same direction
parallel with each other
A
Longitudinal Wave
10
Q
works on both medium/ vacuum
A
Electromagnetic Wave
11
Q
Perpendicular to the direction
A
Transverse Wave
12
Q
mechanical energy that propagates through a medium by compression and rarefraction
A
Sound
13
Q
Reflection of the incident energy pulse
A
Echoes
14
Q
Medium of Sound
A
solid> liquid> gas
solid bcs it is compacted
15
Q
Enumerate Acoustic Variables
A
Pressure
Density
Temperature
Distance
16
Q
Normal audible sound
Human hearing range
A
20 to 20,000 Hz
17
Q
below 20 Hz
A
Infrasound
18
Q
above 20,000 Hz (20kHz)
faster than our ability to hear
A
Ultrasound
19
Q
Therapeutic Ultrasound
A
15 to 20 MHz
20
Q
Diagnostic Ultrasound
A
3 to 10 MHz
21
Q
Construct “acoustic map” of tissues
Acquire and record echoes arising from the tissue interfaces
A
Pulse Echo Technique
22
Q
1790
A
Bats
Naturally produces ultrasound
23
Q
Polarization substances when pressed & basic fundamental principle of UTZ
A
Piezoelectric Effect
24
Q
Piezen means
A
to press
25
Heart of UTZ
Transducer
26
1st piezoelectric material used in transducer
Quartz
27
SONAR
Sound Navigation & Ranging
Used in WW1, to know if there are enemies
28
1980s
1st UTZ machine
as big as iron
29
Biologic Effects
Thermal Effects
Mechanical Effects
30
Tissue absorb ultrasound energy and convert it to heat
Thermal Effects
31
Thermal effect is dependent on the rate of these..
Heat deposition
Heat dissipation
32
movement of particles in the medium
define torque on tissue structures
Radiation pressure
33
known as pulser
provide electrical voltage for exciting the piezoelectric elements
Transmitter
34
produces and detexts ultrasound
converts electric energy to mechanical sonic energy and vice versa
Transducer/ Probe
35
Most expensive part of UTS unit
Transducer
36
Major components of Transducer
Acoustic Lens
Backing Material/ Damping Material
Electrical Connectors
Matching Layer
Physical Housing
Piezoelectric Elements
37
provides structural support
acts as an electrical and acoustic insulator
Physical Housing
38
made of thin film of gold or silver
formed in front and back of the crystal
Electrical Connectors
39
- reduces vibration (ring down time)
- control length of vibration from the front phase
- dampens vibration to create and ultrasound pulse with short spatial pulse length to preserve axial resolution
Backing Material/ Damping Material
40
range of frequencies
Bandwidth
41
reduce beam width of transducer
improves lateral/axial resolution
aluminum, perspex, polystyrene
Acoustic Lens
42
- interface between transducer and tissue/ patient
- minimizes the acoustic impedance differences between the transducer and patient
- improve transmission into the body
Matching Layer
43
- used to eliminate air pockets that could attenuate and reflect the ultrasound beam
- hypoallergenic
Acoustic Coupling Gel
44
How piezoelectric material act..
Electricity (AC) is applied to the piezoelectric material which vibrates (thru expansion & contraction) to produce mechanical sound or pressure waves
45
- converts electrical energy into mechanical energy by expansion & contraction of the crystal structure
- converts mechanical energy to electrical energy by applying mechanical pressure to its surface
Piezoelectric Material
46
Wide/ Broad Bandwidth
shorter SPL
reduce speckle
improved resolution
47
Narrow Bandwidth
longer SPL
narrow frequency
48
Piezoelectric Elements Composition
Synthetic & Natural
49
synthetic:
PZT (Lead Zirconate Titranate)
Barium Titanate
Lead Metaniobate
50
natural:
Quartz
Tourmaline
Rochelle Salt (Sodium Potassium Tartrate Tetrahydrate)
51
black mineral/ prism crystals in granites and rocks
Tourmaline
52
used as laxative, process od silvering mirror
Rochelle Salt
53
best sterilization material
ethyline oxide
54
used in ceramic capacitors
PZT
55
for microphones and transducer
Barium Titanate
56
ceramics
Lead Metaniobate
57
Thicker piezoelectric element
low frequency oscillation
58
Thinner piezoelectric element
high frequency oscillation
59
element will lose its effect at what temperature
300°c
60
rectangular FOV
parallel scan lines
256 to 512 elements
freq: above 4 MHz
for vascular small parts & musculoskeletal
Linear Array (sequential)
61
freq: 3.5 MHz
wide FOV (trapezoidal FOV)
useful in abdominal and obstetrics scanning
Curvilinear Array (sector)
62
small 'sector' FOV
useful in cardiac and cranial ultrasound
Phased Array
63
adjacent to the transducer face
region used for ultrasound imaging
Fresnel Zone or Near Field
64
diverging beam profile
UTS imaging does not extend into this area
Fraunhofer Zone or Far Field
65
region which beam is focused
Focus Zone or Focal
66
resolution in space
Spatial reso
67
resolution of gray shades
contrast reso
68
resolution in time
temporal resolution
69
narrow beam width
better spatial resolution
70
SPATIAL
High Frequency:
better resolution
lower penetrability
higher absorption
71
SPATIAL
Low Frequency:
poor resolution
higher penetrability
lower absorption
72
Components of Spatial Resolution
Axial/ Longitudinal resolution
Lateral/ Azimuthal resolution
Elevation/ Azimuth resolution
73
longitudinal, linear, depth or range
determined by: pulse length
short SPL
Axial resolution
74
transverse, angular, horizontal
determined by: width of UTS beam, depth of object, mechanical and electronic focusing
Lateral resolution
75
determined by slice thickness, dimension of the transducer aperture
Elevation resolution
76
higher frame rate
better temporal resolution
77
Operational Modes
Static Imaging
Real time Imaging
Doppler Modes
78
can be seen in distances between tissue bleeps
reliable in axial resolution
A (Amplitude) Mode
79
shows all tissue traverse by the UTS scan
showm in a series of dots in CRT monitor
B (Brightness) Mode
80
display motion
cardiac valves and chamber walls
M (Motion) Mode/ Ultrasonic Cardiography/ Time Motion Mode
81
DOPPLER EFFECT
Reflected or transmitted frequency is the same amd equal
= 0
Stationary target
82
DOPPLER EFFECT
Differences on reflected and transmitted frequency is lesser than 0
Target motion away from transducer
83
DOPPLER MODE
Use color map to display information based on the detection of frequency shifts from moving targets
determine vessel if artery or vein
Color Flow Doppler Imaging (CD)
84
BART
Blue - Away
Red - Towards
85
DOPPLER MODE
Uses color map to show distribution of the power/amplitude of the Doppler signal
Power Mode Doppler (PD)
86
Other Modes:
Tissue Harmonic Imaging
Spatial Compounding
3D Ultrasound
87
reduces the effect of phase abberations
reduces noise and clutter in image
improves spatial resolution
Tissue Harmonic Imaging
88
combines images obtained by isonating the target from multiple angles
reduces speckle noise
improves contrast
Spatial Confounding
89
Ultrasound Factoring
Gain
Time Gain Compensation TGC
Mode Display
Depth
Resolution Expansion Selection
90
controls the inward incline of the TGC
used to display an even texture throughout the organ or structure under study
Slope
91
control used to delay the start of the slope
delay
92
intensity of returning echoes is amplified to produce a clearer image
Gain
93
too deep:
superficial/ too shallow:
minify image
magnify image
94
zoom box
magnifies part of the image
displaying or measuring small structures (CBD)
Resolution Expansion Selection
95
Image Display
Digital Flat Panel Display
Analog Monitor Display
96
Image Recoding & Storage
Flash Drive
PACS
Photographic Paper
Thermal Paper
VCD
Video Tape Recorder
97
1st image recorder
1990s
simple emulsion film
photographic paper
98
thermal paper
type 1: cheapest, image disappears in a month
type 5: expensive, better, glossy
99
errors in image
does not directly correlate with the actual tissue being scanned
can enhance or degrade the diagnostic value of the ultrasound image
Artifact
100
Interaction of Ultrasound with Tissue
Absorption
Diffraction
Reflection
Refraction
Scaterring
101
propagation velocity
air: 330
lung: 600
fat: 1450
water: 1480
soft tissue: 1540
kidney: 1565
liver: 1555
muscle: 1600
bone: 4080
102
wave interference patterns
Constructive - 2 waves same freq results in a higher amplitude output wave
Destructive - waves out of phase result in a lower amplitude output wave
Complex - waves of different frequencies interacting
103
time from the beginning until the end
period x no. of cycles in the pulse
pulse duration
104
physical length of the pulse
wavelength x no. of cycles in the pulse
spatial pulse length SPL
105
time from the onset of a pulse to the start of the next pulse
pulse duration + listening time
pulse repetition period PRP
106
percentage of the time that the transducer is emttinf soundwaves
duty factor DF
107
first to use sonography for medical
diagnoses
brain tumor
Karl Dussik 1942
108
developed an ophthalmic scanner
Baun
mid 1950s
109
1st successful echocardiogram
Inge Edler
C. Hellmuth Hertz
110
uts in water bath
1MHz
Lym
Putnam
