Ultrasound - Clinical Science Questions and Answers
Ultrasound - Clinical Science Questions and Answers
Ultrasound - Clinical Science Questions and Answers
This set of Clinical Science Multiple Choice Questions & Answers (MCQs) focuses on “Ultrasound”.
Answer: a
Explanation: The ultrasound works on the principle of reflection and refraction. While it is necessary that sound waves need
a medium to travel, so we can say propagation is important but it is only because the sound wave gets refracted when the
medium changes and are reflected back that the image is formed. Thus, the principle for ultrasound is reflection and
refraction.
Answer: c
Explanation: Ultrasound is used for detecting the fault in metal sheets, imaging marine depths and detecting distances. If
the metal sheets have faults like cracks or deformity, the reflected sound waves will not be uniform. SONAR and RADAR are
used to detect distances and work on the principle of ultrasound.
3. Which of the following medical imaging modality other than ultrasound does not use any form of radiation?
a) PET Scan
b) SPECT Scan
c) CT Scan
d) MRI
View Answer
Answer: d
Explanation: MRI uses the electromagnetism of the atoms present in the body to get the images while all the other imaging
modalities use some sort of radioactivity in order to take the images. Ultrasound relies on the sound waves while MRI relies
on the electromagnetic waves. Thus, they are both non radioactive imaging modalities.
4. For which of these areas can the ultrasound be taken for an infant but not for an adult?
a) Cranium
b) Chest
c) Arms
d) Legs
View Answer
Answer: a
Explanation: Bones are natural impedance providers to ultrasound and so if any organ is covered or surrounded by bones, it
is not possible or very difficult to take their ultrasound. For an infant, their bones are soft and do not provide so much of a
resistance to the passage of the ultrasound waves. Thus, it is possible to take an ultrasound of the brain at an infant stage but
not at an adult stage.
5. A piezoelectric crystal is used to produce the ultrasound waves. What kind of ultrasound is produced?
a) Pressure wave ultrasound
b) Electrical wave ultrasound
c) Sound wave ultrasound
d) Simple ultrasound
View Answer
Answer: a
Explanation: A piezoelectric crystal is a special transducer which converts mechanical energy into electrical energy and vice-
versa. Thus, when the electrical impulses are given to the transducer, it is converted into mechanical energy. The transducer
starts vibrating causing a pressure difference and the ultrasound waves are produced.
Answer: b
Explanation: Acoustic impedance is the resistance that a sound wave faces when it propagates from one medium to another
in the body. Thickness, density and water content (for a living body) are all factors that are taken into account when
measuring the acoustic impedance. Thus the medium is characterized by its acoustic impedance. The impedance offered by
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7. The wave velocity of ultrasound in soft tissues is 1540m/s and the impedance offered by it is 1.63 X 106 kg/m2s. What is
the density of the soft tissue?
a) 0.1058441 kg/m3
b) 10.58441 kg/m3
c) 1058.441kg/m3
d) 105844.1 kg/m3
View Answer
Answer: c
Explanation: The impedance is given by z = ρc where z = impedance, ρ = density and c = velocity of the ultrasound. Since the
wave velocity and the impedance offered are given, ρ = z/c. This results in 1058.441 kg/m3 of density for the soft tissue.
Answer: a
Explanation: When the frequency (γ) of the sound waves increases, it gains more energy to overcome the impedance barrier
and so is able to penetrate deeper. However, the penetration may not be uniform in all places and reflection may be uneven
thus it affects the resolution of the image.
Answer: a
Explanation: Acoustic window is a small opening through which the sound waves can pass and can help image the structures
beyond. When the bladder is full, it is properly stretched and the folds of the bladder do not provide any impedance. The
water helps in the better propagation of the sound and visualization of the structures beyond the bladder.
10. What does the red dot on the probe help within the produced image?
a) To check if the correct probe was used
b) To check the probe orientation
c) To check the depth of the probe that was used
d) To check the plane of the image.
View Answer
Answer: b
Explanation: When the probe is being used, it can move in various ways but the image being formed is a horizontal image.
Thus, the red dot at the head of the probe appears to the left of the image and helps in working out the orientation of the
organ or the foetus.
To practice all areas of Clinical Science, here is complete set of 1000+ Multiple Choice Questions and Answers.
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