Fluoroscopy and contrast studies

40 Gulf Prometric Radiographer (DHA, DOH, MOH, SCFHS, QCHP) practice questions on Fluoroscopy and contrast studies, part of Angiography and Fluoroscopy. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Medium

   On an HSG, contrast is seen spilling freely from the fimbrial ends into the pelvis. This finding indicates:

   1. APatent fallopian tubes
   2. BNormal ovulation
   3. CComplete tubal blockage
   4. DPregnancy

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   Answer: A · Patent fallopian tubes

   Free peritoneal spill means that the contrast has passed along the tube and out of its open fimbrial end, which shows patency. Failure to see spill, or a dilated blocked tube, suggests occlusion or hydrosalpinx.

   • B: Ovulation cannot be assessed on HSG.
   • C: Blockage would show no spill, or a dilated tube ending blindly.
   • D: HSG is not a pregnancy test and is avoided in pregnancy.

   Remember this

   Free spill of contrast into the peritoneal cavity demonstrates tubal patency.

2. Question 2 · Medium

   A fluoroscopy timer sounds after 5 minutes of cumulative beam-on time. Its purpose is to:

   1. AStop the procedure automatically and switch the beam off
   2. BSwitch the unit into magnification mode for safety
   3. CPrompt the operator to review the accumulated exposure
   4. DReset the dose area product meter back to zero

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   Answer: C · Prompt the operator to review the accumulated exposure

   The audible alarm reminds the operator and the team that significant exposure has accrued, so they can check whether the procedure remains justified and whether dose-saving steps can be applied. It does not terminate the exposure, and the operator can reset it.

   • A: The timer sounds an alert and does not end the exposure.
   • B: It has no effect on field of view.
   • D: It does not reset any dose meter.

   Remember this

   The 5-minute alarm prompts a review of exposure; it does not stop the beam.

3. Question 3 · Medium

   An image intensifier fluoroscope is switched to a magnification mode with a smaller field of view. The effect on patient dose is that it:

   1. ADecreases, because the beam covers a smaller area
   2. BIncreases, as the system raises output to hold brightness
   3. CFalls to almost zero while the magnified mode is active
   4. DRemains unchanged, because only the display is altered

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   Answer: B · Increases, as the system raises output to hold brightness

   In a smaller field of view the image is produced from fewer collected photons per output area, so the automatic brightness control raises the exposure rate to maintain brightness. Magnification modes therefore give a higher dose and are used only when needed.

   • A: A smaller field does not lower the dose; output rises to keep brightness.
   • C: Dose never falls to zero while the beam is on.
   • D: The dose rate changes with the mode chosen.

   Remember this

   Magnified fields increase the dose rate, so use them only when detail demands it.

4. Question 4 · Medium

   A dose area product (DAP) meter on a fluoroscopy unit measures:

   1. AThe gonadal dose only
   2. BThe skin dose at one point on the patient
   3. CAir kerma multiplied by the area of the x-ray beam
   4. DThe scatter dose at the operator's position

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   Answer: C · Air kerma multiplied by the area of the x-ray beam

   DAP, in Gy.cm2, is the air kerma integrated over the beam cross-section, and it stays almost constant at different distances from the tube. It correlates with total energy delivered to the patient, and is used for audit and diagnostic reference levels.

   • A: DAP does not estimate gonadal dose specifically.
   • B: A point skin dose is given by reference air kerma, not DAP.
   • D: Scatter at the operator needs a separate dosimeter.

   Remember this

   DAP combines air kerma and field area, and reflects total radiation delivered.

5. Question 5 · Easy

   Compared with continuous fluoroscopy, pulsed fluoroscopy mainly:

   1. AReduces patient dose by producing fewer exposures per second
   2. BIncreases patient dose to improve image sharpness
   3. CRemoves the need for collimation
   4. DRaises the tube current during each frame

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   Answer: A · Reduces patient dose by producing fewer exposures per second

   In pulsed mode the tube emits short bursts at a set rate, for example 15 or 7.5 per second, instead of exposing continuously. Fewer pulses per second give less dose, which suits procedures where fast motion does not need to be captured.

   • B: Pulsing is a dose-saving tool, not a dose-adding one.
   • C: Collimation remains essential in every fluoroscopic mode.
   • D: The aim is to reduce, not raise, exposure per frame.

   Remember this

   Lower pulse rates reduce patient dose, so choose the lowest rate that shows the anatomy.

6. Question 6 · Hard

   A patient on metformin with an eGFR of 24 mL/min/1.73 m2 must have an intravenous contrast CT urgently. Following ACR guidance, the best approach is to:

   1. AGive the contrast, then restart metformin at once with the next meal
   2. BProceed if justified, hold metformin 48 hours, recheck renal function
   3. CGive double-dose metformin to protect the kidneys during the study
   4. DCancel, because eGFR below 30 is an absolute contraindication to contrast

   Answer and explanation in LearnFree account

7. Question 7 · Easy

   Barium sulfate is used as a positive contrast agent in gastrointestinal studies mainly because it:

   1. AIs absorbed into the bloodstream
   2. BDissolves completely in water
   3. CHas a lower atomic number than soft tissue
   4. DHas a high atomic number and absorbs x-rays strongly

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8. Question 8 · Hard

   Which of the following contrast agents is iso-osmolar to blood?

   1. AIohexol
   2. BIopamidol
   3. CIoversol
   4. DIodixanol

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9. Question 9 · Easy

   A hysterosalpingogram is best scheduled:

   1. AOn the first day of the period, at the start of bleeding
   2. BAround the expected day of ovulation in mid-cycle
   3. CAny time in the luteal phase after ovulation has occurred
   4. DAfter menstrual bleeding stops and before ovulation

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10. Question 10 · Medium

    A modified barium swallow (videofluoroscopic swallow study) is done to assess swallowing function. Which projection is routine, with the patient seated?

    1. ALateral, to show the airway and aspiration
    2. BAxial through the skull base with the mouth open
    3. CAP supine only, with the head held still
    4. DProne oblique only, with the patient lying down

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11. Question 11 · Hard

    On an intravenous urogram, no contrast has appeared in the collecting system of the left kidney at 15 minutes, though the kidney shows a persistent nephrogram. The most appropriate next step is to:

    1. ARepeat the full contrast injection immediately
    2. BTake delayed films until contrast appears, according to protocol
    3. CEnd the study and report a normal result
    4. DApply abdominal compression to force contrast through

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12. Question 12 · Easy

    Low-osmolar non-ionic contrast agents are generally preferred over high-osmolar ionic agents for intravascular use because they:

    1. ACause fewer adverse reactions and less pain
    2. BAlways give lower radiographic density on images
    3. CContain no iodine, so allergy cannot occur
    4. DAre cheaper to produce than ionic agents

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13. Question 13 · Hard

    A fluoroscopic examination is run at 30 pulses per second and the operator changes to 7.5 pulses per second, with unchanged dose per pulse and the same beam-on time. The dose rate falls by:

    1. A87.5%
    2. B25%
    3. C50%
    4. D75%

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14. Question 14 · Medium

    During fluoroscopy, a radiographer who must stay in the room will receive the lowest scatter exposure by standing:

    1. AOn the detector side, behind a shield or lead apron
    2. BAt the patient's head, close to the beam entry point
    3. CDirectly beside the x-ray tube
    4. DOn the tube side, close to the patient

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15. Question 15 · Hard

    A fluoroscopy tube delivers 20 mGy per minute at the skin when the source-to-skin distance is 40 cm. With the same exposure factors, and treating the tube as a point source, what is the rate at 60 cm?

    1. AAbout 30 mGy per minute
    2. BAbout 13.3 mGy per minute
    3. CAbout 45 mGy per minute
    4. DAbout 8.9 mGy per minute

    Answer and explanation in LearnFree account

16. Question 16 · Medium

    Under US FDA regulations, the minimum source-to-skin distance for a fixed fluoroscopic unit is:

    1. A10 cm
    2. B50 cm
    3. C38 cm
    4. D20 cm

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17. Question 17 · Medium

    A fluoroscopy unit is changed from 30 to 15 pulses per second with the same dose per pulse. The approximate effect on patient dose rate is a:

    1. A50% reduction
    2. BDoubling
    3. CNo change
    4. D25% reduction

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18. Question 18 · Medium

    Under US FDA regulations, the maximum entrance air kerma rate in normal-mode fluoroscopy is about:

    1. A880 mGy per minute
    2. B88 mGy per minute
    3. C10 mGy per minute
    4. D8.8 mGy per minute

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19. Question 19 · Medium

    After a barium enema, the patient should be advised to:

    1. ADrink extra fluids and expect pale stools briefly
    2. BAvoid all fluids for the next 24 hours to rest the bowel
    3. CTake no laxative under any circumstance afterwards
    4. DExpect black stools for a whole week afterwards

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20. Question 20 · Easy

    Before an intravenous urogram, the radiographer should check the patient's:

    1. ABlood glucose only
    2. BBlood pressure in the opposite arm only
    3. CHaemoglobin only
    4. DRenal function and history of contrast reactions

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21. Question 21 · Medium

    An intravenous urogram is requested in a patient with a known abdominal aortic aneurysm. The radiographer should:

    1. ACancel the study without telling anyone
    2. BOmit abdominal compression and tell the radiologist
    3. CApply firm compression to improve filling
    4. DDouble the contrast dose

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22. Question 22 · Hard

    At a fixed entrance air kerma of 20 mGy, the beam is collimated from 10 cm x 10 cm to 5 cm x 5 cm. The dose area product changes from:

    1. A2.0 Gy.cm2 to 1.0 Gy.cm2
    2. B20 Gy.cm2 to 5 Gy.cm2
    3. C2.0 Gy.cm2 to 0.5 Gy.cm2
    4. D0.2 Gy.cm2 to 0.05 Gy.cm2

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23. Question 23 · Medium

    Before a double-contrast barium enema, bowel cleansing is done because retained faeces can:

    1. AMimic polyps and mask real lesions
    2. BIncrease the barium density
    3. CAbsorb the barium into the blood
    4. DReduce patient dose

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24. Question 24 · Medium

    During a power-injected contrast study, the patient reports sudden pain and swelling at the cannula site. The radiographer should:

    1. AContinue the injection and mention it afterwards
    2. BApply a hot pack and continue the injection
    3. CIncrease the flow rate to finish the study quickly
    4. DStop the injection, elevate the arm and assess the site

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25. Question 25 · Medium

    As a larger patient is imaged during fluoroscopy, the automatic brightness control raises the kVp and mA. The consequence for the patient is:

    1. AA lower entrance skin dose rate
    2. BA higher entrance skin dose rate
    3. CA shorter fluoroscopy time
    4. DNo change in dose rate

    Answer and explanation in LearnFree account