Free Diagnostic Radiography Qualifying Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Diagnostic Radiography Qualifying Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1A radiographer notices that a requested lumbar radiograph duplicates an adequate recent examination and asks the referrer whether it will change management. What is the main radiation-protection question being addressed?

   1. A.Whether the expected clinical benefit outweighs the radiation detrimentCorrect answer: A
   2. B.Whether the selected exposure factors produce the required image contrast
   3. C.Whether the measured staff dose remains below its investigation level
   4. D.Whether the detector exposure falls within its calibrated working range

   Explanation: The IAEA states: "Any decision that alters the radiation exposure situation should do more good than harm." The query addresses justification of this patient's exposure. The other checks concern technique, monitoring or detector response after an examination has been justified.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — 24.2.2, p. 617

2. 2After a prolonged image-guided intervention, a patient develops a radiation skin reaction. Once the reaction threshold has been exceeded, what does increasing absorbed dose generally do?

   1. A.The severity increases as dose rises above the thresholdCorrect answer: A
   2. B.The severity remains fixed once the threshold is exceeded
   3. C.The severity decreases as dose rises above the threshold
   4. D.The severity depends on dose only below the threshold

   Explanation: The IAEA states: "Above a particular level of dose, the so-called threshold dose, the severity of the effect necessarily increases with increasing dose." This skin tissue reaction becomes more severe above threshold. The alternative dose–severity relationships reverse or remove that dependence.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — 20.1.1, p. 499

3. 3After assisting a patient with a bleeding wound onto the X-ray table, a radiographer removes gloves and notices visible blood on one hand. Which hand-hygiene method is indicated?

   1. A.Wash with soap and waterCorrect answer: A
   2. B.Apply an alcohol hand rub
   3. C.Wipe with surface disinfectant
   4. D.Rinse with sterile saline

   Explanation: The CDC states: "perform hand hygiene with soap and water when hands are visibly soiled." Visible soil requires washing with soap and water. Alcohol hand rub is preferred in many other clinical situations, but not as a substitute for this washing step.

   Reference: CDC Core Infection Prevention and Control Practices — 5a. Hand Hygiene

4. 4A radiographer must maintain detector air kerma when increasing source–image distance from 100 cm to 150 cm. The original manual setting is 8 mAs. Ignoring attenuation changes, what new setting is required?

   1. A.12 mAs
   2. B.18 mAsCorrect answer: B
   3. C.5.3 mAs
   4. D.3.6 mAs

   Explanation: The IAEA states: "The ISL results in the need for an increase in the mAs as the FID is increased in order to maintain the same air kerma at the image plane." Use mAs₂ = 8 × (150/100)² = 18 mAs. The 12 mAs choice uses a linear distance ratio; 5.3 mAs reverses that linear ratio; 3.6 mAs reverses the squared ratio. No rounding of the correct value is needed.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — p. 122, Inverse square law, equation (6.6)

5. 5A radiographer reviews a technetium radionuclide with mass number 99 and atomic number 43. How many neutrons are present in each nucleus?

   1. A.43
   2. B.56Correct answer: B
   3. C.99
   4. D.142

   Explanation: The IAEA defines: "Atomic mass number A: number of protons Z plus number of neutrons N in an atom (A = Z + N)." Atomic number Z is the proton count. Therefore N = A − Z = 99 − 43 = 56 neutrons. The 43 choice uses proton count; 99 uses the entire nucleon count; 142 adds the two inputs instead of subtracting. No rounding is required.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — 1.3.1, p. 4

6. 6On a sagittal cranial MR image, the radiographer identifies the pituitary gland within the hypophyseal fossa. Which bone forms this fossa?

   1. A.SphenoidCorrect answer: A
   2. B.Ethmoid
   3. C.Occipital
   4. D.Temporal

   Explanation: OpenStax identifies the sella as a "bony region of the sphenoid bone" and states: "The rounded depression in the floor of the sella turcica is the hypophyseal (pituitary) fossa, which houses the pea-sized pituitary (hypophyseal) gland." Thus the pituitary fossa belongs to the sphenoid, rather than the adjacent ethmoid, occipital or temporal bones.

   Reference: OpenStax Anatomy and Physiology 2e — 7.2 > Sphenoid Bone

7. 7The radiographer increases the heating current in an X-ray tube's low-voltage filament circuit. Which component supplies the emitted electrons?

   1. A.The tungsten target
   2. B.The cathode filamentCorrect answer: B
   3. C.The anode rotor
   4. D.The focusing cup wall

   Explanation: The IAEA states: "The filament is heated by a current that controls the thermionic emission of electrons" Heating the cathode filament produces thermionic electrons. The focusing cup directs them; the target receives them and the rotor drives anode rotation.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — p. 93, Components of the X ray tube

8. 8During a CT quality check, a homogeneous water phantom is measured. What is its nominal CT number on the standard Hounsfield scale?

   1. A.−1000 HU
   2. B.+40 HU
   3. C.+100 HU
   4. D.0 HUCorrect answer: D

   Explanation: The IAEA states: "It can be seen that HUwater = 0" Water defines zero on the Hounsfield scale. Air is approximately −1000 HU; +40 HU and +100 HU represent greater attenuation relative to water, rather than its reference value.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — 11.2.2, p. 260

9. 9A radiographer needs the system that archives acquired images and makes them available to multiple review workstations. Which system provides that core function?

   1. A.PACSCorrect answer: A
   2. B.RIS
   3. C.CPOE
   4. D.LIS

   Explanation: The IAEA states: "Grouping such devices together to form a system that manages these tasks produces a picture archiving and communications system (PACS)." PACS manages image distribution, archival and display. RIS manages radiology information/workflow, CPOE handles orders, and LIS manages laboratory information.

   Reference: IAEA Diagnostic Radiology Physics: A Handbook for Teachers and Students — 16.3.1.1, p. 397

10. 10A trauma patient's CT shows gas between the lung surface and chest wall, with partial collapse of the adjacent lung. Which pathological process does this describe?

    1. A.Pleural effusion
    2. B.Pulmonary edema
    3. C.PneumothoraxCorrect answer: C
    4. D.Lobar pneumonia

    Explanation: The source states: "A pneumothorax is a collection of air or gas in the pleural space." The specified gas is in the pleural compartment. Effusion is fluid in that compartment, edema is fluid in lung tissue, and pneumonia is an inflammatory/infective parenchymal process.

    Reference: NHLBI Pleural Disorders — What is pneumothorax?