RADT 146 COMPREHENSIVE EXAM
QUESTIONS AND CORRECT ANSWERS
STUDY GUIDE
●● What are common causes of repeat radiographs?
Answer: Motion, positioning errors, incorrect exposure factors, artifacts,
clipping anatomy, equipment errors
●● Causes of adult repeats in screen/film errors
Answer: 1. Error in exposure factors: over or under exposure
2. Patient (part) positioning
●● CR/DR errors in adults
Answer: 1. Patient (part) positioning
• Exposure errors no longer exist
●● Variables in producing a high-quality radiograph
Answer: - Proper patient positioning
- Proper selection of exposure factors
- Proper use of collimation
●● Poor radiograph
,Answer: - Repeat radiograph, patient re-exposed
- Patient exposure is doubled, receiving unnecessary exposure
●● How do repeat radiographs affect patient exposure?
Answer: They increase radiation dose to the patient
●● Why are repeat rates generally higher in pediatrics?
Answer: Children move more and may not cooperate during imaging
●● What are the risks and benefits of medical radiation?
Answer: Risks: Biological and genetic effects
Benefits: However, it has been proven that the benefits of receiving x-
rays outweigh
those risks. One x-ray can pinpoint a medical problem that otherwise
might be missed by the human eye
●● >30% could be eliminated without compromising the benefits
Answer: - Improvements in modern x-ray equipment
- Accessories
- Radiation safety precautions
●● What are benefits of keeping repeat rates low?
Answer: - Decreases patient exposure
, - Reduce wear and tear of x-ray tube
- Decrease the cost of processing chemicals (for film)
- Increase productivity by decreasing patient time in exam room
●● Pediatric Radiography
Answer: Radiation doses generally less than those received by adults for
the same study
●● Why are pediatric doses generally less than adults?
Answer: Children are smaller and require less radiation
●● Why are pediatric patients more radiosensitive?
Answer: Higher mitotic activity and more immature cells
●● What does the Law of Bergonie and Tribondeau state?
Answer: The radiosensitivity of tissues depends on the numbers of
undifferentiated (immature) cells which the tissue contains, the degree of
mitotic activity in the tissue,
and the length of time the cells of the tissue stays in active proliferation.
●● What 3 criteria increase radiosensitivity according to Bergonie and
Tribondeau?
Answer: 1. Immature/undifferentiated cells
QUESTIONS AND CORRECT ANSWERS
STUDY GUIDE
●● What are common causes of repeat radiographs?
Answer: Motion, positioning errors, incorrect exposure factors, artifacts,
clipping anatomy, equipment errors
●● Causes of adult repeats in screen/film errors
Answer: 1. Error in exposure factors: over or under exposure
2. Patient (part) positioning
●● CR/DR errors in adults
Answer: 1. Patient (part) positioning
• Exposure errors no longer exist
●● Variables in producing a high-quality radiograph
Answer: - Proper patient positioning
- Proper selection of exposure factors
- Proper use of collimation
●● Poor radiograph
,Answer: - Repeat radiograph, patient re-exposed
- Patient exposure is doubled, receiving unnecessary exposure
●● How do repeat radiographs affect patient exposure?
Answer: They increase radiation dose to the patient
●● Why are repeat rates generally higher in pediatrics?
Answer: Children move more and may not cooperate during imaging
●● What are the risks and benefits of medical radiation?
Answer: Risks: Biological and genetic effects
Benefits: However, it has been proven that the benefits of receiving x-
rays outweigh
those risks. One x-ray can pinpoint a medical problem that otherwise
might be missed by the human eye
●● >30% could be eliminated without compromising the benefits
Answer: - Improvements in modern x-ray equipment
- Accessories
- Radiation safety precautions
●● What are benefits of keeping repeat rates low?
Answer: - Decreases patient exposure
, - Reduce wear and tear of x-ray tube
- Decrease the cost of processing chemicals (for film)
- Increase productivity by decreasing patient time in exam room
●● Pediatric Radiography
Answer: Radiation doses generally less than those received by adults for
the same study
●● Why are pediatric doses generally less than adults?
Answer: Children are smaller and require less radiation
●● Why are pediatric patients more radiosensitive?
Answer: Higher mitotic activity and more immature cells
●● What does the Law of Bergonie and Tribondeau state?
Answer: The radiosensitivity of tissues depends on the numbers of
undifferentiated (immature) cells which the tissue contains, the degree of
mitotic activity in the tissue,
and the length of time the cells of the tissue stays in active proliferation.
●● What 3 criteria increase radiosensitivity according to Bergonie and
Tribondeau?
Answer: 1. Immature/undifferentiated cells
