UPDATE COMPREHENSIVE
QUESTIONS AND CORRECT
ANSWERS ALREADY GRADED A+
PASSED 100%
Example of nonspecular reflector CORRECT ANSWER - red blood cells
What happens to spatial pulse length when frequency increases? CORRECT ANSWER -
decreases
Axial resolution is dependent on? CORRECT ANSWER - wavelength
Lateral resolution is dependent on? CORRECT ANSWER - beam diameter
Where does the beam of an unfocused transducer diverge? CORRECT ANSWER - Fraunhofer
zone
Reverberation artifacts are a result of CORRECT ANSWER - two or more strong reflecting
surfaces
True/False: Grating lobes are essential for the proper operation of a linear phased array.
CORRECT ANSWER - False
True/False: Electronically steered scanners always produce higher resolution images than do
mechanically steered scanners. CORRECT ANSWER - False
,True/False: An annular array scanner uses mechanical beam steering. CORRECT ANSWER - True
True/False: A linear sequenced array cannot be dynamically focused. CORRECT ANSWER - False
registration or B-mode alignment CORRECT ANSWER - Which AIUM test object function utilizes
all the groups of wires in the AIUM 100 mm test object?
axial resolution CORRECT ANSWER - Which AIUM test object function utilizes the A group of
wires in the AIUM 100 mm test object?
lateral resolution CORRECT ANSWER - Which AIUM test object function utilizes the B group of
wires in the AIUM 100 mm test object?
dead zone CORRECT ANSWER - Which AIUM test object function utilizes the D group of wires in
the AIUM 100 mm test object?
depth calibration CORRECT ANSWER - Which AIUM test object function utilizes the C or E
groups of wires in the AIUM 100 mm test object?
What happens to axial resolution when spatial pulse length is decreased? CORRECT ANSWER -
improves
How much will a 3.5 MHz pulse be attenuated after passing through 2 cm of soft tissue?
CORRECT ANSWER - 3.5 dB
Propagation speed errors result in CORRECT ANSWER - improper axial position
,Enhancement is caused by CORRECT ANSWER - weakly attenuating structures
The Doppler shift frequency is CORRECT ANSWER - directly proportional to the velocity of the
reflector
The number of frames per second necessary for a real-time image to be flicker free is CORRECT
ANSWER - more than 15
True/False: The SPTA intensity will always be larger than the SATA intensity. CORRECT ANSWER -
True
The intensity of the ultrasound beam is usually greater at the focal zone because of CORRECT
ANSWER - the smaller beam diameter
If the amplitude is doubled, the intensity is CORRECT ANSWER - quadrupled
The attenuation for soft tissue is CORRECT ANSWER - increased with tissue thickness
The acoustic impedance of the matching layer CORRECT ANSWER - can be chosen to improve
transmission into the body
True/False: In a pulse-echo system, the quality factor should be made as large as possible.
CORRECT ANSWER - False
True/False: The beam diameter is constant in the near zone. CORRECT ANSWER - False
The operating frequency is dependent on CORRECT ANSWER - thickness of the crystal
, The period of an ultrasound wave is CORRECT ANSWER - the time of one wavelength
The dynamic range of a system is CORRECT ANSWER - the ratio of smallest to largest power
level that the system can handle
True/False: The intensity of an ultrasonic beam can be measured with radiation force balance.
CORRECT ANSWER - True
Increasing the pulse repetition period CORRECT ANSWER - increases the maximum depth that
can be imaged
Ultrasound bioeffects CORRECT ANSWER - are not confirmed below 100 mW/cm² SPTA
True/False: No refraction can occur at an interface if the media impedances are equal.
CORRECT ANSWER - False
True/False: Smaller transducers always produce smaller beam diameters. CORRECT ANSWER -
False
True/False: The ultrasound beam profile can be measured with a hydrophone. CORRECT
ANSWER - True
True/False: The pulsed-Doppler system yields better depth resolution than the continuous wave
(CW) system. CORRECT ANSWER - True
True/False: The gray-scale display was made possible when digital scan converters replaced
analog scan converters. CORRECT ANSWER - False