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71 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Measures signal strength & how far signal travels in peaks.
-single beam -amplitude -time |
A MODE
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What is the term for the roundtrip time of a sound beam?
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ECHO
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Anything fluid filled
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CYST
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-signals are converted into dots
-basis of real time imaging -displays INTENSITY of echo |
B MODE
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how much energy is in one space
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I
NTENSITY |
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-B Mode dots displayed in a moving time base
-displays TIME and DEPTH -basis of echocardiography |
M-MODE
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-Images are manually realigned and reconstructed into a 3 format
-DEPTH -X,Y,Z axis |
3 DIMENSIONAL(3D)
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-pulsed doppler
-peaks & valleys -change of FREQUENCY -motion of flow detected -sound wave bouncing off a moving RBC -cells moving away & towards inducer -ARTERIAL |
DOPPLER IMAGING
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-place over vessel to test velocity
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GATE
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-first generation scanner
-one dimentional -water |
WATER PATH SCANNER
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-1st generation scanner
-articulating arm |
STATIC B-SCAN
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-still imaging
-used to build 2 D view of tissue -single slice information |
STATIC IMAGING
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-large field of view
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ADVANTAGES TO
STATIC IMAGING |
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-limitied scanning motion
-limited scanning planes -time consuming -requires pt cooperation -very large -can't display movement -high skill of operator required |
DISADVANTAGES TO
STATIC IMAGING |
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-provides cinomatic view of a specific region by displaying a rapid series of images SEQUENTIALLY
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REAL TIME
(DYNAMIC IMAGING) |
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-area of interest easily located
-rapid exam -extended structures can be followed -observation of movements aids in dx -uncooperative pts can be done -portability -pulsed &color flow doppler -can hold probe & move it where needed |
ADVANTAGES OF
REAL TIME IMAGING |
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-term meaning movement
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DYNAMIC
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-soundwaves greater than 20,000 hertz or cycles per second
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ULTRASOUND
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-less than 20Hz
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INFRASOUND
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-the use of high frequency sound to aid in diagnosis & treatment of pts
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DIAGNOSTIC U/S
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-a general unit of frequency
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HERTZ
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-ranges used in medical u/s imaging are 2-15 Hz
-number of complete cyles in any given space |
FREQUENCY
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-use lower frequency for
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PENETRATION
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-use higher frequency
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DETAIL/SUPERFICIAL
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-converting energy by applying pressure to a crystal.
-based ob pulse echo principle |
PIESOELECTRIC
EFFECT |
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-produced by soft tissue
-tissue interacts with the sound -echoes received by transducer crystals interpreted & processed by machine |
ECHO
(TARGET PULSE HITS) |
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-converts one form of energy to another
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TRANSDUCERS
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-sound sent into soft tissues
-sound interacts with soft tissue -pulsing is dertermeined by the dtransducer, not operator controlled |
PULSE FROM
TRANSDUCER |
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-number of times a vave is repeated per second, measured in Hz
-the time it takes a pulse to travel back to the transducer |
FREQUENCY
(THE BETTER DEF) |
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-the upswing of waves;highest pressure as crystals are vibrating
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COMPRESSION
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-soundwaves at the lowest pressure (crystals are relaxed)
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RAREFACTION
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-the principle at which u/s operates
-pulse emitted;echoes return |
PULSE ECHO PRINCIPLE
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-1.54 mm/us
-1540 m/s |
PROPAGATION SPEED
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-contains several piezeoelectric elements (crystals)
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TRANSDUCER
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-single beam
-contains 1 transducer element -manually sweeping of a sound beam thru the tissues |
AUTOMATIC SCANNING
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-contains several transducer elements called ARRAYS(multiple crystals)
-arranged in straight line-linear array -a curved line - curved array |
ELECTRONIC SCANNING
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-2.25mHz-large or pregnant
-3.5mHz- average -5.0mHz- thin adults, peds -7.5mHz- superficial, thyroid,breast, testes -10.0-14.0MhZ + - latest advancements for superficial |
TRANSDUCER
SELECTION |
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-endovaginal(transducer)
-rectal -biopsy -intraoperative -endoluminal -transcranial(baby heads) |
OTHER TRANDUCERS
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-linear
-vector -sector(phased array) -curved array(convex array) |
4 TYPES OF
TRANSDUCERS |
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-made of many vertical paraell scan lines
-rectangular image -used for OB,small parts, vascular |
LINEAR TRANSDUCERS
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-larger field of view
-put pics side by side -easy to measure large mass |
ADVANTAGES OF
LINEAR TRANSDUCER |
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-big
-cant see between ribs -hard to manipulate |
DISADVANTAGES OF
LINEAR TRANSDUCER |
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-compacted crystals that diverge causing small fov
-pie shaped image -used in all types -sound beams do not come out paraell |
VECTOR
TRANSDUCER |
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-smaller
-manipulate thru ribs -for baby heads |
ADVANTAGES OF
VECTOR TRANSDUCER |
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-limited NEAR field of view
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DISADVANTAGES OF
VECTOR TRANSDUCER |
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-pie shaped image
-all types of imaging, commonly cardiac -time delay- elements are fired out with delays |
SECTOR TRANSDUCER
(aka PHASED ARRAY) |
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-echocardiology
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ADVANTAGES TO
SECTOR TRANSDUCER |
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-limited NEAR field of view, misses alot of information
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DISADVANTAGES TO
SECTOR TRANSDUCER |
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-pie shaped
-convex @ near field -used in all types -diverged sound beams |
CURVED ARRAY
TRANSDUCER (aka CONVES ARRAY) |
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-more dpth
-a lil wider than vector in near field & far field -good for larger structures |
ADVANTAGES TO
CURVED ARRAY TRANSDUCER |
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-hard to see between the ribs
-limited FOV |
DISADVANTAGES TO
CURVED ARRAY TRANSDUCER |
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-uses curved array transducers
-goes inside vagina |
ENDOVAGINAL
TRANSDUCER |
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-empty bladder
-better resolution -see fetal heartbeats early @ 5 weeks |
ADVANTAGES
ENDOVAGINAL TRANSDUCER |
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-uncomfortable
-invasive -move probe alot -small FOV -large mass hard to measure -stool and gas in way |
DISADVANTAGES
ENDOVAGINAL TRANSDUCER |
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1. examine each organ seperately, sat & trans on each organ
2. examine each organ throughly 3.formulate your diagnostic impression 4.document your diagnostic impression |
FOUR STEPS TO
ORGAN SCANNING |
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-scans are organ oriented
-perpendicular to organ -angled to organ -subcostal -intercostal -rotated |
SCANNING
METHODS |
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1.reflection
2.absorption 3.scatter |
3 WAYS SOUNDWAVES
REACT |
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-strong back wall enhancement
-anechoic/sonolucent -smooth contours -well defined borders -sound wave speeds up after passing thru |
CYSTIC
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-weak or no back wall
-possible shadowing -not homogenous -irregular borders -internal echoes -decreases thru-transmission -soundwaves scatters - |
SOLID
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-masses
-tumors -smooth and irregular borders -segmented -both cystic and solid |
COMPLEX
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-producing echoes
-reflects sound with bright intensity -lots of echoes stones,bone,fat aka hyperechoic or echo-rich |
ECHOGENIC
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-produces no echoes
-fluid filled -transmits sound easily -vascular,bladder aka sonolucent,echolucent,HYPOechoic |
ANECHOIC
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-uniform compostion
-same echo intensity through out liver,thyroid,testes,pancreas,spleen |
HOMOGENOUS
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-MIXED echoes
-not uniform -different echo intensities tumors,normal kidneys |
HETEROGENEOUS
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-absorbtion or reduction in sound strength as it travels thru tissue
-caused by reflection,absorption,scatter |
ATTENUATION
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-through transmission
-opposite attenuation -sound travels thru anechoic structure and is not attenuated |
ENHANCEMENT
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-sound does not pass thru object
-sound beam is absorbed by a solid stones,dense tumors |
SHADOWING
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-echos delineate(pass thru) the boundry of an organ
-diaphragm -strong reflectors -best seen when probe is perpendicular to organ aka boundry |
INTERFACE
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THE INCREASE OF ECHO AMPLITUDE FROM AN INTERFACE THAT LIES BEHIND A WEAKLY ATTENUATING STRUCTURE
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BOOK DEFINITON
OF ENHANCEMENT |
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DECREASED AMPLITUDE FROM REFLECTORS (INTERFACE) LIE BEHIND A STRONGLY REFLECTED STRUCTURE
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BOOK DEFINITION
OF SHADOWING |
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1. Border of structure
2.Texture of structure 3.Sound transmission of structure 4.Characteristics of the structure |
CRITERIA TO EVALUATE ABNORMAILITES
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