Final exam Flashcards
How does one view a lateral projection?
Lateral projections, which are marked by R or L by side of patient closest to the IR, are viewed from the same perspective as the x-ray tube or by the radiologist’s preference.
How does one view a PA or AP oblique projection?
The same way a true PA or AP is viewed: with the patient’s right to the viewer’s left.
How does one view a decubitus chest and/or abdomens?
The way the x-ray tube “sees” them.
How does one view upper and lower limbs?
As if you were looking from the x-ray tube. Images that include digits placed with digits up. Other images of limbs viewed in the anatomical position.
How are CT or MRI images viewed?
Axial images are generally viewed so the patient’s right side is to the viewer’s left.
What are exposure factors (technique)?
The three exposure variables that are set on the control panel of the x-ray machine by the radiographer each time an image is produced. (kV, mA, seconds)
ALARA
As low as reasonably achievable
What is the name of the measurement of radiation in the air?
Roentgen (R)
What is the name of the measurement of radiation used for patient dose purposes?
Rad
What is the measurement term used for worker protection purposes?
Rem
What is the SI unit corresponding to Roentgen?
Coulombs/kg of air
What is the SI unit corresponding to Rad?
Gray (Gy)
What is the SI unit corresponding to Rem?
Sievert (Sv)
What are precautions taken for pregnant technologists?
A second monitoring device is issued for fetal monitoring. The mother does not have to alter her work schedule.
What is the recommended maximum equivalent does to the fetus of a pregnant technologist?
0.05 rem (50 mrem, .5 mSv) per month and .5 rem (500 mrem, 5 mSv) for the gestational period.
Types of personnel monitoring:
film badge, TLD (thermoluminescent dosimeter), & OSL (optically stimulated luminescence).
Where are dosimeters worn?
At waist or chest level or on collar during fluoroscopy.
What are ALARA principles?
Always wear a personnel monitor, radiology personnel should not restrain patients, Use sound radiographic exposure factors, and follow the cardinal rules of radiation protection, which are Time, distance and shielding.
Fluoroscopy safety practices are:
Bucky slot cover, lead drape, .5 mm lead apron, exposure limit of 10 R/min.
Ways to protect the patient during exam:
Minimum repeat radiographs, give clear instructions, use proper positioning and exposure factors, including correct filtration and close four sided collimation, specific area shielding, protection for pregnancies.
Types of collimators
Manual and Positive-beam limitation (PBL)
Types of shielding:
Shadow shields and contact shields.
Properties of Gonadal contact shields:
1mm lead equivalent, reduces dose 50% to 90%.
Center for Devices of Radiologic Health guidelines for gonadal shielding:
- If the gonads lie within or close to the primary x-ray field (about 5 cm from) despite proper beam limitation.
- If the clinical objective of the exam is not compromised.
- If the patient has a reasonable reproductive potential.