#1
What is the typical frequency range of diagnostic ultrasound?
1 - 10 MHz
ExplanationCommon diagnostic ultrasound frequencies range from 1 to 10 MHz.
#2
Which unit is used to measure the intensity of ultrasound waves?
Watt per square meter (W/m²)
ExplanationUltrasound intensity is measured in watts per square meter.
#3
Which of the following is a unit of ultrasound frequency?
Hertz (Hz)
ExplanationUltrasound frequency is measured in Hertz.
#4
What is the term for the number of ultrasound cycles per unit time?
Frequency
ExplanationFrequency measures the number of ultrasound cycles per unit time.
#5
Which of the following materials is commonly used as a coupling medium in ultrasound imaging?
Water
ExplanationWater is frequently used as a coupling medium in ultrasound.
#6
Which property of ultrasound waves determines penetration depth in tissues?
Frequency
ExplanationHigher frequency allows shallower penetration.
#7
What is the main advantage of using a higher frequency ultrasound probe?
Higher spatial resolution
ExplanationHigher frequencies provide finer detail in imaging.
#8
Which of the following is true regarding Doppler ultrasound?
It measures blood flow velocity.
ExplanationDoppler ultrasound detects blood flow velocities.
#9
What is the term for the phenomenon where ultrasound waves scatter and reflect off structures?
Reflection
ExplanationUltrasound waves bounce off tissue interfaces.
#10
What is the main limitation of ultrasound imaging in comparison to other imaging modalities like CT or MRI?
Limited penetration depth
ExplanationUltrasound's depth penetration is shallower than CT or MRI.
#11
Which statement accurately describes the piezoelectric effect in ultrasound transducers?
It converts mechanical energy into electrical energy.
ExplanationPiezoelectric effect transforms mechanical stress into electrical signals.
#12
In ultrasound imaging, what does A-mode represent?
Amplitude of echoes along depth
ExplanationA-mode displays echo amplitude versus depth.
#13
What is the relationship between ultrasound frequency and resolution?
Higher frequency improves spatial resolution.
ExplanationIncreasing frequency enhances image sharpness.
#14
Which of the following is a characteristic of acoustic impedance?
It is inversely proportional to density.
ExplanationAcoustic impedance decreases with increasing density.
#15
What is the term for the range of frequencies present in an ultrasound pulse?
Bandwidth
ExplanationBandwidth represents the span of frequencies in an ultrasound pulse.