1. RAD 354 Chapt. 16 Image QUALITY
“Finite” Radiographic quality
Noise
Resolution
Spatial resolution
Contrast resoultion

2. Film/Screen Factors Speed of the “system” Characteristic Curve
Digital vs Film/screen
Optical Density
Factors directly and indirectly effecting density
Log Relative Exposure
sensitivity of the human eye

3. Contrast Image contrast Subject contrast
How to compensate for subject contrast
Film/screen contrast
Image receptor/film screen contrast
Film/receptor processing

4. Geometric factors Magnification Distortion Focal spot blur
Direct vs distortion
Mag factor vs mag ratio
Distortion
Focal spot blur
Sid – Oid relationships
Heel effect

5. RAD 354 Chapt. 17 Image Artifacts
Usually TECHNOLOGIST dependant
Patient Preparation
Clothes left on (zippers, jewelry, dentures)
Positioning errors (patient, tube, bucky, receptor)
Wrong screen-film combination
Upside down film casstte/receptor

6. Processing Artifacts Roller marks Cascading (curtain effect/run down)
Guide shoe lines
Pi lines
Dirty rollers
Chemical fog
“Wet-pressure sensation” varied amount of pressure on the rollers = uneven film “splotches”

7. Handling Artifacts Light/Radiation Fog Kink marks
Sensitivity prior and after exposure
Kink marks
Static (Tree, smudge are the most common)
Hypo retention (test is mandatory for mammo)

8. RAD 354 Chapt. 18 Quality Control
Quality Assurance is a JCAHO required 10 step PEOPLE process
Quality Control is an imaging intrumentation and equipment process

9. QC- 3 Step Process Acceptance testing Routine performance monitoring
Maintenance

10. Radiography QC Filtration – annually
Collimation – semiannually (+/-2% of the SID)
F.S. size Annually (+/-50%) Frequently MISSED parameter!
kVp calibration – annually (+/-10%)
Exp. Timer Accuracy – annually (based on ms used – more leeway with longer exposures)
Linearity – annually (+/-10%) of same mAs with differing mA/times – but SAME mAs
Exp. Reproducibility – Same cont./Dens., etc when exposures are repeated

11. Focal Spot Check Tools/Frequency
Annually
Pin hole camera (somewhat hard to use)
Star Pattern (down to .3 mm sizes)
Slit camera – easiest to use/preferred method

12. Other RAD QC Filtration Collimation (PBL) kVp/Timer
Exposure Linearity (same mAs with varied mA and times)
Intensifying screens
Protective apparel
Film illuminators
Computer station monitors

13. Fluoro QC Exposure rate Spot film exposures
Automatic Exposure System (ABS – AEC)

14. Tomo QC
Tube travel/Arc
Fulcrum level
Pt. Expossure

15. Processor QC
See table 18-8 (p. 313) for QC for RAD Processor items/intervals
Processor Maintenance
Scheduled maintenance
Preventative maintenance
Non-scheduled maintenance

16. Processor Monitoring Temperatures Replenishment
Sensitometry/Densitometry