QCP For Radiographic Units Flashcards
Quality control program for rad units
Visual inspection
Environmental inspection
Performance testing
Includes checking the main components of the equipment for the proper function
Visual inspection
Visual isnpection should be done
Annually
Contain all selector for the production of xray
Control panel
Visual inspection
Control panel
Overhead tube crane
Radiographic table
Protective lead apparel
Control panel inspection
Tube heat sensor
Overload protector indicator
Panel light
Mounting braket that holds the xray tube over the xray table
Overhead tube crane
Items to inspect include surface condition and cleanliness , angulation switches , angulation indicator, footboard and shoulder braces
Radiographic Table
Protective apparel should be radiographed or viewed fluoroscopically every
Six months
Miscellaneous Equipment
Calliper presence
Technique chart
Positioning accessories
Intravenous stands
Mechanical and electrical safety
Includes evaluation of electrical cables and xray tube
Environmental Inspection
Environmental inspection should be done
Annually
Evaluates the performance of the xray generator and xray tube
Performance testing
Data obtained in performance testing includes radiation measurements
Radiation measurements
Most common type of detector
Geiger-Mueller Counter
Value obtained from radiation detector is also the
Radiation intensity (roentgen/coulomb per kg)
Produce tge same intensity of radiation each time the same sets of technical factors are used
Reproducibility
Max variability allowed in reproducibility is
+- 5 %
Evaluation of reproducibility requires
Dosimeter
Reproducibility variance
(mRmax-mRmin)/(mRmax +mRmin)
Emit a specific amount of radiation per unit of xray tube current and time
Radiation output
Amount of radiation
mR
uC/kg
Unit of xray tube current
mAs
Radiation output testing original acceptance value should be
10 %
Necessary to remove low energy photons
Proper filtration
Method to determine presence of adequate filtration
Half value layer
Taking half the maximum dosimeter reading and drawing a line from this point to the absorbed thickness
Filtration check (hvl)
Hvl should be
> 2.3mm at 8kvp , 50mAs
Has asignificant effect on the image contrast
Tube voltage
Kvp accuracy should be
5%
Directly affects thetotal quantity of radiation
Exposure time
Used to regulate tube temperature
mA selector
Same mAs selected but with different combination of mA and exposure time
Reciprocity
Reciprocity variation
10%
Raciprocity variance
= ((mR/mAs max - mR/mAs min) / mE/mAs ave) / 2
Sequencial increase in mAs
Linearity
Linearity variance is
10%
Linearity variance =
(( mR/mAs max - mR/mAs min) / mR /mAs ave ) /2
Area of the anode that is being bombarded
Focal spot
Focal spot size increase w/ age
Blooming
Used to evaluate blooming
Pinhole camera
Responsible for regulating size of xray field
Beam restricting system
BRS should be done
Twice a year
How well the collimator regulates field size
Light field - Radiation Field Congruence
LF Congruence within
2%
Equipment with positive beam limiting device
Image receptor - radiation field alignment
IR congruence
3%
Collimator dials to the size of x and y
Accuracy of x-y scale
Light source should be ______ at 100 cm distance
15 ft - c (160 lux)
Used for evaluation of illuminator bulb brightness
Photometer
Xray beam should mounted properly in metal housing
Beam alignmet
