General

Question 1

If you increase the frequency 2 times, how much will the axial resolution improve?

Frequency =

Axial resolution =

Spatial Pulse Length =

Answer 1

Frequency = C/wavelength
Axial resolution = Spatial Pulse Length/2
Spatial Pulse Length = n x wavelength

Question 2

So increasing frequency 2 x will cut the ________ by ½….reducing the ______ by ½ ….improving the _______ by reducing it to ½ of what is previously was

Answer 2

wavelength

SPL

axial resolution

Question 3

what are the units for:

Spatial Pulse Length = n x wavelength
Attenuation = Coefficient x depth

Answer 3

(mm) = (mm)

(dB) = (dB/cm) x (cm)

Question 4

What is the wavelength of a 2 MHz transducer in soft tissue?

Given
F = 2 MHz
C = 1.5 mm/us
Wavelength = ?

Answer 4

C mm/us = F (MHz) x wavelength (mm)

Question 5

What is the ratio of 50 to 100?
What is the value in decimals?
What is the value in a percentage?

Answer 5

50: 100 or 50/100
0. 5

.5 x 100 = 50%

Question 6

Change 100 meters to kilometers.

Change 1,000 micrometers to millimeters.

Change 1 millimeter to meters.

Answer 6

100 m = .1 km

1,000 um = 1 mm

1 mm = .001 m

Question 7

Force per unit area is the definition of ________. what is it measured in?

Change in velocity divided by the time over which the change occurs is the definition of _________.what is it measured in?

Answer 7

pressure. Measured in Newtons per meter squared (N/m2).

acceleration. Measured in meters per seconds squared (m/s2).

Question 8

If the frequency is increased 2 times, what happens to wavelength?

If the Intensity reflection coefficient (IRC) is 0.1 and the reflected intensity (Ir) is 5 mW/cm2, what is the incident intensity?

If the Intensity reflection coefficient (IRC) is 0.1, what percentage of the incident ultrasound is reflected?

The Doppler shift frequency is 100 kHz, what is it in megahertz?

Pressure, density and volume are acoustic variables. What happens to each of them during compression?
Pressure:
Density:
Volume:

Question 9

Which of the following is the angle of transmission?

Question 10

_____ is similar to echolocation used by bats, whales and dolphins.

it was first used to detect ____ (1906) and then in the military to detect ____ (1915)

Answer 10

ultrasound

icebergs, submarines

Question 11

what does SONAR stand for?

when did ultrasound become recognized s a medical tool?

Answer 11

Sound Navigation and Ranging

1950’s

Question 12

what method of us began in 1970’s and is method used today. Allows visualization of motion, which is advantageous for:

Patients that can not hold still or hold breath
Visualizing moving structures (bowel/hernias, diaphragm, fetus, heart, infant hips)

Answer 12

real time dynamic imaging

Question 13

____ is used to evaluation blood flow in vessels. First used clinically in 1980’s.

Answer 13

doppler

it Provided a spectral waveform. Early 1990’s brought color Doppler.

Question 14

what do digital systems allow for?

Answer 14

manipulation of data, digital storage and sending

Question 15

Ultrasound – frequency above audible range, _____ Hz

Diagnostic range ____MHz.

Answer 15

>20,000 Hz.

1-17

Question 16

___________ technique is US sent into body, reflects off structures and returns to the transducer. Instrument/computer processes the reflections into an image.

Answer 16

Pulse-echo technique

Question 17

To create a real-time image the beam must be moved through the patient _______

_______ scan lines (lines of site) make up one image (frame)

Multiple frames in rapid sequence make a _________

Answer 17

“rapidly and repeatedly.”

A series of

“real- time” image.

Question 18

High frequency = _____ resolution, _____ penetration

Low frequency = _____ resolution, _______ penetration

Answer 18

better, less

poorer, better

Question 19

Instrument displays reflections on the image at a depth based on _________, a position based on ___________ and brightness based on ______________.

Answer 19

echo return time, scan beam direction, amplitude of the reflection

Question 20

If you increase the frequency 2 times, how much will the axial resolution improve?

Answer 20

Frequency = C/wavelength
Axial resolution = Spatial Pulse Length/2
Spatial Pulse Length = n x wavelength

So increasing frequency 2 x will cut the wavelength by ½….reducing the SPL by ½ ….improving the axial resolution by reducing it to ½ of what is previously was

Question 21

Spatial Pulse Length (mm) =

Answer 21

n x wavelength (mm)

Question 22

Attenuation (dB) =

Answer 22

Coefficient (dB/cm) x depth (cm)

Question 23

What is the wavelength of a 2 MHz transducer in soft tissue?

Given
F = 2 MHz
C = 1.5 mm/us
Wavelength = ?

Answer 23

C mm/us = F (MHz) x wavelength (mm)

Question 24

Force per unit area is the definition of ______

Change in velocity divided by the time over which the change occurs is the definition of _______

Answer 24

pressure. -Measured in Newtons per meter squared (N/m2).
acceleration. Measured in meters per seconds squared (m/s2).

Question 25

If the frequency is increased 2 times, what happens to wavelength?

If the Intensity reflection coefficient (IRC) is 0.1 and the reflected intensity (Ir) is 5 mW/cm2, what is the incident intensity?

If the Intensity reflection coefficient (IRC) is 0.1, what percentage of the incident ultrasound is reflected?

The Doppler shift frequency is 100 kHz, what is it in megahertz?

Question 26

Pressure, density and volume are acoustic variables. What happens to each of them during compression?

Pressure:
Density:
Volume:

Question 27

Which of the following is the angle of transmission?

Answer 27

Question 28

formula symbols and units

Answer 28

Question 29

what are their #s in 10’s?

Answer 29

Question 30

what do you multiply by for the following?

Answer 30

Question 31

what do you multiply by for the following?

Answer 31

Question 32

If units are getting smaller, # must get _________

Answer 32

larger. And vise versa