VIR Radiation Safety & Protection 2

Question 1

Where should the primary monitoring dosimeter badge be worn when a lead apron is used in the VIR suite?

Accepted Answer

At the collar level, outside the lead apron

Answer

The primary dosimeter is worn at the collar level outside the apron to estimate dose to the unshielded head, neck, and thyroid—the highest-exposure unprotected regions.

Question 2

The lead equivalency of a standard full wrap-around lead apron used in interventional radiology is typically:

Accepted Answer

0.5 mm Pb equivalent

Answer

Standard lead aprons provide 0.5 mm Pb equivalent protection, which attenuates approximately 90–95% of scatter radiation at typical fluoroscopic energies.

Question 3

Which action most effectively reduces patient entrance skin dose during fluoroscopy?

Accepted Answer

Placing the image receptor close to the patient

Answer

Placing the image receptor close to the patient prompts the automatic exposure control (AEC) to reduce X-ray output, thereby lowering patient entrance skin dose.

Question 4

Pulsed fluoroscopy reduces radiation dose compared to continuous fluoroscopy primarily because:

Accepted Answer

Radiation is only emitted during discrete pulses rather than continuously

Answer

Pulsed fluoroscopy delivers X-rays only during brief intervals rather than continuously, reducing total dose proportional to the duty cycle and the selected frame rate.

Question 5

The recommended annual occupational dose limit for the lens of the eye according to NCRP Report 116 is:

Accepted Answer

150 mSv (15 rem)

Answer

NCRP Report 116 recommends an annual occupational dose limit of 150 mSv (15 rem) for the lens of the eye, reflecting its sensitivity to radiation-induced cataract formation.

VIR - Vascular-Interventional Radiology Practice Test

VIR - Vascular-Interventional Radiology Practice Test

VIR Radiation Safety & Protection 2