Self Test: Part G
What is the SI unit of radiation measurement for absorbed dose?
Gray
Which term is replacing "exposure" to describe skin dose?
Air kerma
What is the annual whole body effective dose (ED) for a technologist?
50 mSv or 5 rem
What is the cumulative lifetime ED for a 25 year old technologist?
250 mSv
What is the annual ED limit for an individual younger than 18 years of age?
1 mSv or 0.1 rem
The federal set maximum limit on exposure rates for intensified fluoroscopy units is:
10 R/minutes
For most modern equipment, the average fluoroscopy tabletop exposure rate is:
1 and 3 R/minutes
What is the primary purpose of x-ray tube filtration?
Absorb lower (unusable) energy x-rays
Which of the following results in the highest ED for females (assuming no specific area shields are used)?
AP thoracic spine (14 X 17 inch collimation)
The use of a 1-mm lead equivalent gonadal shield reduces the gonadal dose by _________ if the gonads are within the primary x-ray field.
50% - 90%
Which type of shield is ideal when the affected tissue is part of a sterile field?
Shadow shield
True/False:
Low kV and high mAs techniques greatly reduce patient dose compared with high kV and low mAs techniques.
False
True/False:
The total ED for females on an AP chest projection is more than double for that of a PA chest.
True
True/False:
The use of a positive beam limiting (PBL) collimator is no longer required by the FDA for new x-ray equipment manufactured after 1994.
True
True/False:
Collimators must be accurate within 5% of the selected SID.
False
Which of the following is not one of the cardinal principles of radiation protection?
Distance
Time
Shielding
Collimation
Collimation
Which one of the following changes will best reduce patient dose?
Decrease kV and increase mAs
Increase kV and lower mAs
Using a grid
Increase mAs and lower kV
Increase kV and lower mAs
Where is the safest place for the technologist to stand during a fluoroscopic procedure?
behind the radiologist
Which of the following protection devices must be employed during a fluoroscopic procedure?
Bucky slot shield
Lead gloves
Compensating filter
Restraining devices
Bucky slot shield
The ED for a pregnant technologist per month is:
0.5 mSv (0.05 rem)
True/False:
A fetal personnel dosimeter is worn at the level of the waist by a pregnant technologist during fluoroscopy.
True
True/False:
All administrative staff in the radiology department must wear a personnel dosimeter even if not involved with patient care directly.
False
True/False:
The ICRP and ARC have determined that the "10-day rule" is obsolete for procedures of the abdomen and pelvis.
True
True/False:
ALARA does not apply to digital imaging.
False
True/False:
Using a different algorithm to process an overexposed CR image is an acceptable and ethical practice.
False