Ultrasound

Question 1

Diagnostic ultrasound also called ?

Answer 1

Diagnostic Medical Sonography , Sonography
and Ultrasonography

Question 2

Diagnostic uses ?

Answer 2

Cardiology , GIT , Gynecology , Obstetrics
Ophthalmology , Urology

Question 3

What are Obstetric ultrasound used for ?

Answer 3

Date the pregnancy (gestational age)
Confirm fetal viability
Determine location of fetus, intrauterine or ectopic
Check for the number of fetuses (multiple pregnancy)
Check for major physical abnormalities
Assess fetal growth

Question 4

Sound ?

Answer 4

Sound energy is mechanical which exist from physical movement of molecules and particle in medium
Sound waves cannot travel propagate on vacuum

Question 5

What is physical movement of molecules and particle in medium is called ?

Answer 5

Sound

Question 6

What is Diagnostic ultrasound ?

Answer 6

Imaging using non-ionizing, high frequency sound to generate images of tissues in the body

Question 7

what is procedure of diagnostic ultrasound ?

Answer 7

Sound waves are transmitted into body
structures as a small transducer is passed over the patient’s skin

Question 8

Difference between sound and ultrasound ?

Answer 8

Is a mechanical wave that travels in a straight line (which can be heard by humans is 20 -20,000 Hz )

Ultrasound: Is a wave with a frequency greater than the upper limit of human hearing
(2 – 20 MHz)

Question 9

What sound is ?

Answer 9

Is mechanical wave , Is longitudinal wave , Is type of pressure and form of energy

Is NOT ionizing radiation , Is NOT transverse wave and Is NOT an electromagnetic wave

Question 10

Doppler and color doppler introduce ?

Answer 10

In 1980s

Question 11

Real time scanner used ?

Answer 11

In late 1970s

Question 12

Uses of 2D US made in ?

Answer 12

In early mid of 1970s

Question 13

Properties of sound waves ?

Answer 13

Velocity , Frequency , Wavelength
and Amplitude

Question 14

Velocity ?

Answer 14

The speed of a sound wave through a medium
Units of measure are distance/time
cm/sec

Question 15

Speed of sound is determined by what ?

Answer 15

Density and stiffness of the medium in which it travels (slowest in air/gasses)

Question 16

What velocity depends on ?

Answer 16

On the medium it’s traveling through
speed of sound in ?
air = 300 meters/second
water = 1,480 meters/second
bone = 4,080 meters/second

Question 17

Frequency ?

Answer 17

The number of cycles occurring in one sec of times
( cycles per sec)

Question 18

Units to describe frequency ?

Answer 18

Hertz = 1 cycle in one second
Kilohertz (kHz) = 1,000 cycles per second (or 1,000 Hertz)
Megahertz (MHz) = 1,000,000 cycles per second (or 1,000,000 Hertz)

Ultrasound imaging frequency range is 2-13 MHz

Question 19

Wavelength ?

Answer 19

Length OR space over one cycle (distance)

Question 20

Amplitude ?

Answer 20

The strength/intensity of the sound wave at any given point in time

Represented by the height point in the wave

Question 21

Ultrasound machine consist of what ?

Answer 21

An important part which is Probe OR transducer OR Scan head probe which produces “pulses” of ultrasound waves

Question 22

The reflected waves return to the probe and processed by ?

Answer 22

ultrasound machine – image processing

Question 23

An image which represents these reflections is formed ?

Answer 23

Monitor

Question 24

Reflection ?

Answer 24

occurs at interface between two adjacent tissues

The difference in acoustic impedance (z) between the two tissues causes reflection of the sound wave

The greater the difference in acoustic impedance between two adjacent tissues, the greater the reflection

Question 25

What ultrasound image is formed from ?

Answer 25

Reflected echoes

Question 26

Scattering ?

Answer 26

Redirection of the sound wave in several directions
Caused by interaction with a very small reflector or a very rough interface

Question 27

Transmission ?

Answer 27

Not all of the sound wave is reflected, therefore some of the wave continues deeper into the body
These waves will reflect from deeper tissue structure

Question 28

What is Attenuation ?

Answer 28

The deeper the wave travels in the body, the weaker it becomes

The amplitude/strength of the wave decreases with increasing depth

Question 29

What are basic US instrument ?

Answer 29

Beam generation
Reception of the retaining echo
Image processing
Image display

Question 30

Transducer ?

Answer 30

It is (probe) which made of Piezoelectric crystal

Emit sound after electric charge applied
Sound reflected from patient

Is a device that can convert one form of energy into another form Electrical energy to US (vice versa)

Question 31

Depth of penetration ?

Answer 31

The HIGHER the frequency, the LESS it can penetrate into the body
The LOWER the frequency, the DEEPER the penetration

Question 32

Image display ?

Answer 32

Four different modes of ultrasound are used in medical imaging. These are:
A-mode (amplitude)
M-mode (time-motion)
B-mode (real time)
Doppler ( measure blood flow)

Question 33

Allows assessment of dynamics ?

Answer 33

Real time imaging

Question 34

Used in 1950s , and considered one of the safest modalities ?

Answer 34

Non - ionizing radiation

Question 35

Coupling Gel ?

Answer 35

A gel is used on the skin

Question 36

Has low acoustic impedance and high reflectivity is ?

Answer 36

Air

If there is air between the transducer and the skin then the U/S is reflected