Ch11-12 Flashcards
A diagnostic type tube housing protects the patient from
Off focus and leakage radiation
The radiographic table should be uniform thickness and radiolucent; most are made of
Carbon fiber
The patients skin surface should be ___cm away from the collimator.
15cm
PBL dimensions require not to exceed __%
2%
Total filtration is what 2 factors together?
Added and inherent
X-ray equipment operating over 70kvp should have a filtration of aluminum thickness to
2.5mm aluminum
Compensating filters are used such as:
The trough =chest
He wedge=femur , foot
Exposure linearity and Kvp setting should be within the___%
10% range of selected kvp
The use of a grid increases patient dose but improves
Contrast and visible detail
For mobile radiography, the SSD should be no less than
12 inches
Sheets of aluminum
Added filtration
The brightness
Luminance
The distance from anode focal spot to IR
SID
The glass envelope encasing the tube, the insulating oil, and the glass window of the tube housing
Inherent filtration
A term used for candelas per square meter
Nit
The photoconductor used to convert X-rays to electrical signals
Amorphous selenium
When is the use of a grid required??
Anything over 70kvp
10cm thickness
To reduce patient dose in flouro, the distance to the image intensifier should be
As short as possible
The sharper the image, the ______ the pixels
Smaller
Height/distance =
For lead lines on a grid
Grid ratio
Is generally located outside the glass window of X-ray tube housing above collimator shutters
Added filtration
Placing the 1st pair of shutters in the collimator as close to the X-ray tube window will
Reduce patient dose from off focus radiation
Th genetically significant dose (GSD) for US is
.20mSv
Air gap can be used in alternative to a
Grid
Correctly placed gonadal shilding will protect women by _____ and men by _____
50%
90-95%
To accomadate involuntary motion; a shorter exposure time and increased____ May be used
mA
A _______ _________ program should ensure that standardization in postprocessing of digital images is done.
Quality control
The goal of image gently is to make awareness of
Lower radiation doses for pediatric patients
A blotchy image causes by insuffient quantity of X-ray photons is called
Quantum noise/mottle
The use of air gap can compensate there what type of grid ?
8:1 grid
The dosimeter That measures the skin directly
TLD
Which uses LiF crystals
_____ _____ shields are not recommended for PA projections bcuz of anterior and lateral surfaces are not covered
Shaped contact
Bone marrow dose may also be referred to as
Mean marrow dose
For safety of female organs, the shield should be approximately _____ medial to palpable ASIS
1inch
4 types of shields
Flat, shaped, shadow, clear
3 ways to specify radiation received by a patient
ESE, bone marrow, gonadal dose
What can facilities and radiographers do with image gently ??
They can “Pledge” to follow them in their dept.
What type of shield is used for the lens of the eye??
A contact shield
What percent of lead of weight should a clear shield have??
30%
The female reproductive organs receive _____ times more then men during radiographic procedures
3x
Filtration increases the ________ of the X-ray bean.
Quality !!
As it removes low energy X-rays
Aluminum has the atomic # of
Z=13
The numeric values of a digital image are aligned in rows an d columns called
An array
A scintillator =
A photoconductor=
Amorphous silicon
Amorphous selenium
Common image matrix are
1024x1024
CR uses ________ in its image receptor using Eu as th activator.
Photostimulable phosphor
The most effective protective shield are the
Flat contact shields
1mm lead thickness
The mean marrow dose is 25% of what the ____________ dose is bcuz the radiation is spread all over the body it is not accurately calculated.
Bone marrow dose
To follow ASRT and ARRT code of ethics, the —
FGP(flourospocally guided positioning)
*Used to locate CR
Damage is unlikely to occur to newborn babies if the exposure is under
0.2Gy
