CH 8 Flashcards
Diagnostic yield versus diagnostic efficacy
Yield: amount of useful information produced by image
Efficacy: accuracy of information on image
X-ray machine design features
Tube
Tube support
Collimator
Radiographic table
X-ray generator/control
Upright image receptor
Radiographic table
Fixed or variable height
“Floating” table top
Radiolucent
May have tilting capability (wont have height capabilities)
X-ray tube supports
floor mounted or ceiling suspended
- facilitate easy and efficient positioning around patient
- Moves, transverse, longitudinal, vertical, rotates
Types of IR
Cassette based systems
- film screen
- CR
Digital radiography systems
- Flat panel technology
- thin film transistors (TFTs)
The only radiation that is of any clinical value is ____________
Remnant
- converted to signal then sent to computer
PSP Tech (CR)
- latent image consists of electron traps on plate
- housed in light tight cassette
- inserted into CR reader
- CR reader opens cassette and scans with low energy laser beam
- Plate that has been scanned is exposed to intense white light
- Clean plate is reinserted into cassette for reuse and ejected from reader
Important CR considerations
- CR plates are extra sensitive to low energy radiation after they have been exposed
- Electron traps can dissolve with lengthy delays in processing
- spatial resolution difference among cassette sizes
Mobile fluoroscopy
Used in surgery
C– arm design
Fixed SID and center to x-ray tube
Limited power
Video monitors and digital enhancement included in monitor cart
Digital tomosynthesis
-flat panel digital detector
-multiple images during single “sweep”
-view images in scrolling fashion
Dual energy subtraction
- flat panel digital detector
- Two rapid exposures, back to back, high kVp and low kVp
- Data points analyzed and similar data removed from file which causes final image to reveal selected subtracted anatomy
DXA
Dual emission X-ray absorptiometry
- Used to assess bone health
Mammography
Study of breast tissue
CT
Acquires images of patients in axial plane
Sonography
Ultra high frequency sound waves
MR
Nuclear magnetic fields in radiofrequency emissions from select nuclei
Radionuclide imaging
Nuclear medicine
Employees radiopharmaceuticals
Detected by a GammaRay camera
Radiation oncology
Use a very high x-ray energy for therapeutic purposes, which are intended to destroy cancers tissues
