LMRT-Radiography Essentials 209 Questions and Answers Which of the following changes in (KVP) will result in the greatest reduction of patient dose, when (MAS) is adjusted to compensate for the change? - Correct Answer Increase kVp by 30% Which of the following (IR) system speeds will result in the lowest patient dose? - Correct Answer Faster speed IR system What is the primary purpose of using gonad shields during radiography? - Correct Answer Reduce the likelihood of genetic effects Contact & shadow are two types of gonad shield - Correct Answer TRUE When should gonad shields be used? - Correct Answer When the gonads are within 5cm of the radiation field The greatest cause of unnecessary radiation to patients that can be controlled by the limited operator
are: - Correct Answer repeat exposures
The limited operator can reduce repeat exposures by: - Correct Answer clearly instructing patients How does x-ray beam restriction minimize patient exposure - Correct Answer It limits the radiation field to the area of interest What is the device that allows the limited operator to vary the size of the radiation field - Correct Answer Collimator How does filtration reduce patient exposure - Correct Answer Removes longer wavelength photons What is the National Council on Radiation Protection and Measurements (NCRP) recommendation for the amount of total filtration - Correct Answer 2.5mm Al Equivalent 1 / 3
What are the three principal methods used to protect limited operators from unnecessary radiation exposure? - Correct Answer 1. Time
- Distance
- Shielding
- Glove
- Thyroid shield
- Shadow******** CORRECT
Which of the following is NOT a type of personnel radiation shielding? - Correct Answer a. Apron
Personnel shielding must be worn on the rare occasion during which the limited operator may need to remain in the radiographic room during an exposure to assist the patient in maintaining the proper position. What is the source of the greatest radiation hazard under this circumstance? - Correct Answer Scattered radiation from the patient What is the term from radiation that escapes from the x-ray tube housing? - Correct Answer leakage radiation Why are limited operators prohibited from activities that result in direct exposure to the primary x-ray beam? - Correct Answer They are considered occupationally exposed individuals Distance, as a method used to limit operator exposure, means that: - Correct Answer the operator should maximize the distance from the source during an exposure.Shielding worn for personnel protection is designed to attenuate what source of exposure - Correct Answer scatter radiation Which of the following is an acronym for a common type of personnel dosimeter - Correct Answer TLD 2 / 3
What is the recommended placement for a personnel dosimeter on the body of the limited operator - Correct Answer The badge should be worn in the region of the collar on the anterior surface of the body and outside the lead apron if worn.What is the NCRP recommended annual effective dose limit for occupational exposure - Correct Answer 5.0 rem (0.05 severt) What is the NCRP recommended monthly effective (or equivalent) dose limit to the fetus for a prego worker? - Correct Answer 0.05 rem (0.0005 Sv) Radiation monitoring of personnel is required when what percentage of the annual occupational effective dose limit is likely to be received - Correct Answer 10% What is the conventional (British system) radiation unit to express radiation intensity in air? - Correct Answer Roentgen The conventional unit commonly used to report occupational dose to radiation workers in the U.S. is
the: - Correct Answer rem
What is the conventional (British system) radiation unit of absorbed dose - Correct Answer Rad According to the Bergonie Tribondeau law, which of the following types of cells are most radiosensitive?
- Correct Answer Embryonic tissue cells
- / 3
Which type of x-ray photon interaction with the body is primarily responsible for the radiation dose absorbed by the pt? - Correct Answer Photoelectric What is the (NCRP) recommendation for lead equivalency of aprons used for personnel protection? - Correct Answer 0.5 mm What is erythema, as it relates to radiation exposure? - Correct Answer reddening of the skin caused by a high radiation dose