X-Ray Certification Patient Protection 3 — Questions and Answers
Question 1: Which type of radiation interaction deposits the most dose in superficial skin tissue during diagnostic x-ray imaging?
- Compton scatter
- Coherent scatter
- Photoelectric absorption (Correct answer)
- Pair production
Correct answer: Photoelectric absorption
Photoelectric absorption involves complete absorption of the photon by tissue atoms, depositing all its energy locally and contributing the most to skin dose.
Question 2: A flat contact shield placed directly on the patient's skin is most effective for protecting:
- Deep abdominal organs
- The lens of the eye
- Superficial radiosensitive gonads in males (Correct answer)
- The thyroid gland
Correct answer: Superficial radiosensitive gonads in males
Flat contact (shadow) shields placed directly over the testes are highly effective because the gonads are superficial and close to the surface.
Question 3: What does the term 'effective dose' measure in radiation protection?
- The total energy absorbed by the patient
- The entrance skin exposure in roentgens
- The whole-body equivalent dose that accounts for tissue radiosensitivity (Correct answer)
- The dose rate at a fixed distance from the tube
Correct answer: The whole-body equivalent dose that accounts for tissue radiosensitivity
Effective dose incorporates tissue weighting factors to express the overall risk from partial-body irradiation as an equivalent whole-body dose.
Question 4: Which pediatric patient factor requires the radiographer to reduce technique compared to an adult of similar size?
- Higher bone density in children
- Greater tissue radiosensitivity and smaller body part thickness (Correct answer)
- Children's faster movement requiring shorter exposure times
- Pediatric patients require more kVp for adequate penetration
Correct answer: Greater tissue radiosensitivity and smaller body part thickness
Children have more radiosensitive tissues and thinner body parts, requiring lower technique to avoid over-exposure and minimize dose.
Question 5: The 10-day rule in radiography historically referred to scheduling elective pelvic/abdominal exams on female patients during which period?
- The first 10 days of pregnancy
- The first 10 days following the last menstrual period (Correct answer)
- Within 10 days of a previous exposure
- Any time the patient is under age 10
Correct answer: The first 10 days following the last menstrual period
The 10-day rule recommended scheduling non-urgent pelvic/abdominal x-rays during the first 10 days of the menstrual cycle when pregnancy is least likely.
Question 6: Which of the following is the most radiosensitive organ in the human body?
- Brain
- Muscle tissue
- Bone marrow (Correct answer)
- Kidney
Correct answer: Bone marrow
Active bone marrow (red bone marrow) is one of the most radiosensitive tissues due to its rapidly dividing hematopoietic cells.
Question 7: Using a faster (higher speed) image receptor system primarily benefits patient protection by:
- Improving spatial resolution of the image
- Requiring less radiation exposure to form the image (Correct answer)
- Increasing contrast of the image
- Reducing the need for repeat exposures
Correct answer: Requiring less radiation exposure to form the image
Faster receptor systems require less radiation to produce a diagnostic image, directly reducing patient dose.
X-Ray Certification Patient Protection 3
Which type of radiation interaction deposits the most dose in superficial skin tissue during diagnostic x-ray imaging?