Sonography

Question 1

sound waves beyond audible range use frequency of

Answer 1

1-10 MHz

Question 2

transmission of high frequency mechanical vibrations

Answer 2

greater than 20 kHz

Question 3

desciribed by the Curie brothers in 1880
principle by which the ultrasound beam is produced
states that when certain crystals undergo mechanical deformation, a potential difference develops across the two surfaces of the crystals

Answer 3

piezoelectric effect

Question 4

descibes the property of certain crystals such as quartz, expading and contracting in response to the application of electircal filed

Answer 4

pressure electric

Question 5

device that converts energy from one form ot another

converts electrical energy fo ultrasonic energy

Answer 5

ultrasound transducer

Question 6

measures the ability to distinguish between adjacent structures

Answer 6

resolution

Question 7

a propgation of energy that moves back and forth or vibrates at a steady rate

Answer 7

acoustice wave

Question 8

ultrasonic wave can be focused, refracted, reflected, or scattered between different media
a factor in determing what happens to an ultrasound beam at interfaces with different media

Answer 8

acoutic imedance

Question 9

reduction of acoustic amplitude along propagation pathway as a result of diffraction, absorption, scattering, reflections or any other process that redirects the signal away from the receiver

Answer 9

attenuation

Question 10

sound waves that reflected by internal structures back to the transducer

Answer 10

echoes

Question 11

is a propagation of energy that moves back and forth or vibrates in a steady rate

Answer 11

acoutic wave

Question 12

are mechanical oscillation that are transmitted by particles in gas, liquid, or solid medium

Answer 12

sound waves

Question 13

referes to sound waves beyond the audible range of 16,000 - 20,000 hz

Answer 13

ultrasound

Question 14

diagnostic ultrasound uses

Answer 14

1-10 MHz

Question 15

bending wave fronts

Answer 15

refraction

Question 16

acoutic energy relected from a structure that interferes with the expected path

Answer 16

reflection

Question 17

diffusion or redirection of sound in different directions

Answer 17

scattered

Question 18

to concentrate the sound beam into a smaller beam area than would exist without focusing

Answer 18

focused

Question 19

determined by the density and elastic properties of the medium

Answer 19

velocity of sound

Question 20

impedes sound transmission (lungs, stomach, bowel)

Answer 20

air

Question 21

attenuates sound

Answer 21

bone

Question 22

sound varies slightly from one tissue to another

Answer 22

soft tissue

Question 23

multiple frames per second over selected areas of the body
ability to visualize structures as they change position such as peristalsis in the bowel and stomach & pulsatile vascular and cardiac structures

Answer 23

real time imaging

Question 24

a change in frequency when the motion of laminar or turblent flow is detected within a vascular structure
makes possible the determination of velocity and direction of flow of blood

Answer 24

doppler effect

Question 25

techinique that assings a color scale to the change in frequency or dopple shift

Answer 25

color-flow doppler

Question 26

signifies direction of flow towards the tranducer

Answer 26

red

Question 27

shift away from the transducer

Answer 27

blue

Question 28

is used inside transducer, behind the piezoelectic element to absorb useless vibration

Answer 28

damping material or backing