Relationships
How are period and frequency related?
Inversely
Which number matches the following: 2.56 x 10 -5
a. 25,600
b. 0.000256
c. 0.0000256
d. 256,000
c. 0.0000256
Which of the following describes an angle with a measure of 100 degrees?
a. orthogonal
b. acute
c. obtuse
d. perpendicular
C. obtuse
The area that starts at the beam's smallest diameter and extends deeper is:
a. the distant zone
b. the Fresnel zone
c. the Fraunhofer zone
d. the focus
c. the Fraunhofer zone
A video display that is limited to black and white only, with no shades of gray, is called:
a. binary
b. bistable
c. monochrome
d. inchworm
b. Bistable
only black and white
How are pulse repetition period and imaging depth related?
Directly
What are the units for impedance?
a. Pascals
b. Hertz
c. mm
d. Rayls
d. Rayls
A sound pulse travels in Medium 1 and strikes an interface with another tissue, Medium 2, at 45 degrees. The angle of transmission is 15 degrees. Which medium does sound travel slowest?
a. Medium 1
b. Medium 2
c. They are the same speed
d. Cannot tell
b. Medium 2
It will be slowest
If you change transducers from a 2 MHz to a 7 MHz, what will happen to the focus?
a. It will be shallower
b. It will be deeper
c. The focus will not change
d. You will have more divergence
b. The focus will get deeper as the frequency increase
The process of eliminating low amplitude signals from further processing is called all of the following except:
a. Threshold
b. Reject
c. Subordination
d. Suppression
c. Subordination
Reject can also be called threshold or suppression
How are frequency and attenuation related?
Directly
The higher the frequency the more attenuation
What is the reciprocal of 0.05?
a. 2
b. 20
c. 1/2
d. 1/20
b. 20
What is the propagation speed of a 5 MHz sound wave in soft tissue?
a. 0.22mm
b. 1.54 m/s
c. 0.308 mm
d. 1540 m/s
d. 1540 m/s
Bonus Question for all Teams!!!!
First team to draw and label the 7 components of a transducer wins these points!
7 components:
Case
Wire
PZT
Matching layer
Damping material/ Backing layer
Acoustic insulator (inner)
Electrical shield (outer)
Which transducer has the best axial resolution?
A. 4MHz
B. 8 MHz
C. 10 kHz
D. 2 MHz
B. 8 MHz
Highest frequency will give the best axial resolution.
How are imaging depth and frame rate related?
Inversely
The deeper it goes the less frames we get
Which of the following cannot be considered a unit of frequency?
A. per day
B. cycles/sec
C. Hz
D. cycles
d. cycles
The term does not inform us of the duration of these events, this choice is incomplete and not a unit of frequency.
For refraction to occur which two incidence must occur?
Oblique angle
Different speed of two media
Huygens' Principle is based on: ______
a. refraction
b. Bernoulli's Law
c. transverse waves
d. interference
d. interference
The hourglass-shaped beam is caused by the interference of waves
All of the following are true of write magnification except:
a. It is a preprocessing function
b. The same number of pixels are in the original ROI and the zoomed image
c. The pixel size in the zoomed image and the ROI are the same
d. In comparison to the zoomed image, fewer ultrasound pulses are used to create the original ROI
b. There will be more pixels than the original ROI
With write magnification the image is rescanned
Which of the following PRFs would give you the lowest PRP?
a. 2 MHz
b. 25 kHz
c. 30 nHz
d. 28 GHz
d. 28 GHz
Attenuation has what units?
a. Decibels
b. Distance
c. Hertz
d. Pascals
a. dB
A sound beam with an intensity of 45 W/cm2 strikes a boundary and 70% of the wave's intensity is reflected. How much is transmitted?
A. 45 W/cm2
B. 25 W/cm2
C. 30%
D. 100%
C. 30%
reflected + transmitted = incident
70% + ____ = 100%
Which of the following techniques is external focusing?
a. lens
b. curved crystal
c. electronic
a. lens
focusing with a lens is external
focusing with a curved PZT is internal
electronic focusing is done with phased array
What are the 5 requirements a contrast agent must meet?
Safe
Metabolically inert
Long lasting
Strong reflector of ultrasound
Small enough to pass through the capillaries