Transcript Chapter 10, (6th ed)

Chapter 11,
th
(7
ed)
Equipment Design for Radiation
Protection
Radiographic equipment which is
designed to protect the Rt and the
patient
Collimation is always important for the
Pt. as well as the RT
This is known as a diaphragm
Seldom used currently due to
computerized imaging systems
Filter (The best thing ever invented to
reduce Pt. dose)
Moly anodes used in Mammo to
create a more monochromatic beam
Are grids radiation dose reduction
devices?
CR VS Film
Pt. and Rt. protection
Image intensification
Dose reduction—What do you do?
Fluoro dose reduction
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Time
Collimate
Where do you stand?
Last image hold
Pulsed fluoro
High-level control VERY high dose to Pt & RT
See p. 236-8 box & table
List of dose reduction measures
X-ray housing/tube assembly:
3 phase & high frequency generators
Stable high voltage generators
Collimator on tube housing window to stop off focus radiation
Filtration & heavy metal filters
Adequate collimation
Image Receptor:
CR / DR systems allow for higher KVP & total dose reduction
Reduction of repeats
Windowing and leveling allow for less images being produced.
Fluoro
Image ingtensifier, 5 minute timer, dead man switch, filter on fluoro tube, lead in table to protect Rad.
Last image hold
Pulsed fluoro
CT
Protocols that reduce dose
THERE IS GREAT INTEREST IN DOSE REDUCTION IN ALL AREAS OF DIAGNOSTIC IMAGING TODAY.
(THERE ARE MORE. WHAT CAN YOU THINK OF?)
End Ch. 11 (7th ed.)
For an x-ray photon to be of any diagnostic
value, what three things must happen to it?
Originate for close to a point source
Travel in a straight line
Stop in the pt. or continue on to the IR