Solutions
"whole body dose" for the purposes of external exposure Correct
Answers head, trunk, arms above elbow, legs above knee
24 hour notification is required if an an indiv has received
within 24hours Correct Answers - a total effective dose equiv
exceeding 5rems
- an eye equiv exceeding 15 rems
-a shallow dose of equiv to the skin or extremities exceeding 50
rems
25% of retakes Correct Answers positioning errors
50% of retakes are from Correct Answers error in exposure
factors
absorbed dose in rad Correct Answers is equal to 1 rem
absorded dose = Correct Answers rad (or gray -SI units)
advantages of high kVp technique Correct Answers -reduced
skin entrance dose
-shorter exposures, which lessen the chance for motion blurring
of the image
-increased radiographic latitude
-improved control of radiographic contrast
-less heat impressed into the x-ray tube because of greater x-ray
production efficiency at higher voltages
,ALARA Correct Answers as low as reasonably achievable
an artifact Correct Answers is any density on a radiograph that
is caused by something not belonging to the part being x-rayed
any other person holding a patient Correct Answers -must be
protected with appropriate shielding
-must not be struck by the useful beam
-must be wearing a monitoring device
-should not be occupationally exposed
as distance from x-ray source is doubled Correct Answers the
radiation intensity is reduced to 1/4 at original distance
at higher energies the prob of Compton interaction Correct
Answers is greater
at least once a day Correct Answers a sensitometric strip should
be passed through the film processor to allow measurement of
fog, speed and contrast
avoid film fogging Correct Answers -use proper safelight
-not exposing film to ionizing radiation in film storage area
-not processing films in a contaminated dev'lper
bone characteristics Correct Answers effective # 13.8
density 1.85
abundance in % 10
bone has the density Correct Answers nearly twice that of water
, carcinogenic effects Correct Answers ---
cassettes may become bent or warped if they are dropped or
improperly stored. Correct Answers the use of such warped
cassettes will produce localized unsharpness on the finished
radiographs
even a small fingernail solution or cigarette ashes on the screens
will def produce artifacts
cataractogenic effects Correct Answers --
cells in order of diminishing sensitivity Correct Answers -
lymphocytes or WBC
-erthrocytes or RBC, granunocytes
-epithelial cells
-endothelial cells
-connective tissue
-bone
-muscle
-nerve
-brain
Collimation Correct Answers (X-ray beam restriction/area
exposed field size). Collimation of the useful or primary X-ray
beam to the area of clinical interest is required by law.
**Collimation is one of the most important actions X-ray
personnel can take in order to avoid unnecessary radiation dose
to the patient**
compton scattering Correct Answers interaction of a photon of
x-rad with an orbital electron of an absorber atom producing a