Free Practice Quiz Question List

8 Radiation and Medical Imaging Online Quiz Questions

Use this free practice quiz with 20 questions to review 8 Radiation and Medical Imaging, test your knowledge, and prepare for your next test or exam.

20 questions

Choose one

1 point

Which statement correctly describes MRI in relation to ionizing radiation?

A
MRI uses X-rays to form images.
B
MRI uses non-ionizing energy and does not use X-rays.
C
MRI detects gamma rays emitted by a radiopharmaceutical.
D
MRI displays X-ray images continuously to guide procedures.

True or false

1 point

True or false: A patient's effective dose precisely predicts that individual's risk from an imaging examination.

A
True
B
False

Fill in the blank

1 point

SPECT forms images by detecting emitted from a radiopharmaceutical inside the body.

Choose one

1 point

A clinician needs cross-sectional images reconstructed from X-ray measurements taken around a patient. Which imaging method fits this description?

A
It detects radiation emitted by a radiopharmaceutical and displays the emissions directly.
B
It sends one X-ray beam through the body and records a single projection.
C
It collects X-ray transmission measurements from many angles and reconstructs cross-sectional images.
D
It uses sound waves to create continuous images during a procedure.

Choose all

1 point

Select all correct statements about X-ray interactions in diagnostic imaging.

A
Photoelectric absorption can contribute to image contrast.
B
Coherent scattering usually deposits substantial energy in tissue.
C
Compton scattering can reduce image contrast when scattered photons reach the detector.
D
Photoelectric absorption changes a photon's direction while leaving its energy essentially unchanged.

Fill in the blank

1 point

For imaging staff, increasing from the radiation source helps reduce occupational exposure.

Choose one

1 point

Why can an iodine- or barium-based contrast agent make a selected structure easier to see on an X-ray image?

A
They emit paired photons after positrons annihilate with electrons.
B
They attenuate X-rays strongly, making selected structures easier to see.
C
They make the X-ray beam non-ionizing.
D
They prevent all X-rays from interacting with tissue.

Choose all

1 point

Select all statements that correctly describe the two central radiation-protection principles in medical imaging.

A
Justification weighs the expected benefit of an examination against its potential harm.
B
Optimization uses the lowest dose that provides image quality adequate for the clinical task.
C
Optimization requires repeating images until every detail is visible, regardless of dose.
D
Justification means selecting the test with the highest dose available.

Written response

1 point

Which X-ray interaction can send photons to the detector from the wrong direction and thereby reduce image contrast?

True or false

1 point

True or false: Ultrasound and MRI use non-ionizing energy rather than X-rays.

A
True
B
False

Written response

1 point

For the model $I = I_0 e^{-\mu x}$ , let the initial intensity be 100 intensity units, the attenuation coefficient be $0.2\ \text{cm}^{-1}$ , and the material thickness be $5\ \text{cm}$ . What is the predicted transmitted intensity, rounded to one decimal place? Answers within 0.1 intensity units are accepted.

Choose one

1 point

During a procedure, a clinician needs X-ray images displayed continuously or in rapid succession to guide actions. Which method is most appropriate?

A
Radiography, because it reconstructs cross-sectional images from many angles.
B
PET, because it detects paired photons from tracer annihilation.
C
Fluoroscopy, because it displays X-ray images continuously or in rapid succession.
D
SPECT, because it detects gamma rays emitted from a radiopharmaceutical.

Open ended

1 point

Explain how absorbed dose differs from effective dose. Include what each quantity represents, its unit, and one limitation on how effective dose should be interpreted.

True or false

1 point

True or false: Skin injury is the main radiation-protection concern at the relatively low doses typical of routine diagnostic imaging.

A
True
B
False

Choose one

1 point

A patient may be pregnant and needs imaging to answer a clinical question. Which response best reflects the recommended approach?

A
Avoid all medically necessary imaging because any radiation exposure is unacceptable.
B
Tell the care team, so it can consider the situation and choose an appropriate approach, including a suitable non-ionizing test when appropriate.
C
Proceed without telling the care team because dose is independent of the patient and imaging settings.
D
Request repeated images to ensure that the exposure is justified.

Choose one

1 point

A radiograph shows contrast between bone and an air-filled region. Which explanation best accounts for this contrast?

A
Air-filled regions attenuate more X-rays than bone.
B
Bone attenuates more X-rays than air-filled regions.
C
Bone and air-filled regions attenuate the same fraction of X-rays.
D
Bone creates contrast by emitting X-rays toward the detector.

Choose one

1 point

A clinician wants a selected structure to stand out more clearly on an X-ray image. Why might an iodine- or barium-based contrast agent help?

A
They emit paired photons that a detector uses to form an image.
B
They reduce attenuation so more X-rays reach the detector.
C
They attenuate X-rays strongly, making selected structures easier to see.
D
They prevent X-rays from interacting with tissue.

Choose one

1 point

A scan collects X-ray transmission measurements from many angles around a patient and then produces cross-sectional images. Which imaging method is being used?

A
It measures X-ray transmission from many angles and reconstructs cross-sectional images.
B
It detects only radiation emitted by a radiopharmaceutical inside the body.
C
It displays a single X-ray projection continuously without reconstruction.
D
It uses sound waves to construct images from reflected echoes.

Written response

1 point

A clinician decides whether to perform an ionizing-radiation examination by weighing its expected clinical benefit against its potential harm. What is the name of this radiation-protection principle?

Written response

1 point

For a narrow, monoenergetic beam passing through a uniform material, use $I=I_0e^{-\mu x}$ . If $I_0=100$ intensity units, $\mu=0.20\,\text{cm}^{-1}$ , and $x=5\,\text{cm}$ , calculate $I$ . Enter the result in the same units as $I_0$ ; answers within 0.2 intensity units are accepted.