1. Quality Control

2. HIGH QUALITY FILMS REPRODUCES ANATOMICAL IMAGE EXACTLY FILM HAS:
CORRECT TECHNICAL FACTORS
NO MOTION
NO ARTIFACTS
PROCESSED CORRECTLY

3. RESOLUTION ABLE TO VISUALLY SEPARATE OBJECTS
BONE VS. TISSUE-- IE: SPATIAL RESOLUTION
CR VS CONVENTIONAL FILM
DIFFERENCES BETWEEN DIFFERENT TISSUES-- IE: CONTRAST RESOLUTION
CR VS. CONVENTIONAL FILM

4. NOISE FILM GRAININESS (INHERENT) SIZE OF FILM CRYSTALS
STRUCTURE MOTTLE (INHERENT), PHOSPHOR IN SCREEN
QUANTUM MOTTLE

5. QUANTUM MOTTLE
LOW NUMBER OF X-RAY PHOTONS INTERACTING WITH SCREEN. INSUFFICIENT AMOUNT OF PHOTONS STRIKING INTENSIFYING SCREEN CAUSING AN INSUFFICIENT LIGHT TO EMIT FROM PHOSPHOR CRYSTALS.
How do we adjust technique for this?
CR and Quantum Mottle

6. SPEED A FILM’S ABILITY TO RESPOND TO X-RAY EXPOSURE
IF FILM “A” RECORDS MORE DENSITY SOONER THAN FILM “B”, WHICH FILM HAS A HIGHER SPEED? A

7. SENSITOMETRY
MEASUREMENT OF SENSITIVITY TO LIGHT AND THE FILM’S RESPONSE TO CHANGES IN TECHNIQUE AND PROCESSING.

8. DENSITOMETRY
MEASUREMENT OF THE DENSITY OF THE FILM BASED ON THE PERCENTAGE OF LIGHT TRANSMITTED THROUGH THE FILM.

9. ANATOMY OF A CHARACTERISTIC (H & D CURVE)

11. OVERHEADS!!!!!!!

13. RECIPROCITY LAW OD REMAINS THE SAME NO MATTER THE LENGTH OF EXPOSURE
100 mA X 1 sec = 100 mAs ↓↓
200 mA X .5 sec= 100mAs ↓↓
400 mA X .25 sec =100mAs →→same OD
500 mA X .2 sec = 100mAs ↑↑
Applicable to direct screen exposures

14. RECIPROCITY LAW FAILURE
FILM/SCREEN RADIOGRAPHY
EXPOSURE TIMES LESS THAT 10 MILLISECONDS
EXPOSURE TIMES GREATER THAN 5 SECONDS
INTERVENTIONAL STUDIES
MAMMOGRAPHY

15. RADIOGRAPHIC CONTRAST
IMAGE RECEPTOR CONTRAST
PLUS
SUBJECT CONTRAST

16. IMAGE RECEPTOR CONTRAST
Formerly known as film contrast. Why the change in name?
Inherent to film
Affected by processing

17. SUBJECT CONTRAST SIZE SHAPE
X-RAY ATTENUATION OF THE ANATOMY AND ENERGY OF BEAM

18. REVIEW L ATITUDE (REMEMBER THIS IN REFERENCE TO THE FILM)
W I D E LATITUDE = LOOOOONNNNG GRAY AKA LOW OR LONG SCALE CONTRAST
NARROW LATITUDE = SHORT SCALE =HIGH CONTRAST

19. WIDE LATITUDE FILM, BECAUSE OF LONG GRAY SCALE ALLOWS AS MUCH AT 15% ERROR BY RADIOLGRAPHER

20. MAGNIFICATION FACTORS
MOST IMAGES ARE LARGER ON RADIOGRAPH THEN IN ACTUALITY DUE TO SID AND SOD!
FOR EVERY 1” INCREASE IN OID, SID MUST BE INCREASED BY 7” TO COMPENSATE FOR MAGNIFICATION

21. SID AND SOD? SID: SOURCE TO IMAGE DISTANCE
SOD: SOURCE TO OBJECT DISTANCE
MAG. FACTOR IMAGE SIZE OR SID
OBJECT SIZE SOD
TO FIND SOD SUBTRACT THE OID FROM THE SID

22. IF YOU COULD MEASURE A HEART AND IT MEASURED 12
IF YOU COULD MEASURE A HEART AND IT MEASURED 12.5 CM BUT ON THE RADIOGRAPH IT MEASURED 14.7 CM, THE MAGNIFICATION FACTOR WOULD BE CALCULATED AS 14.7 DIVIDED BY 12.5 WHICH EQUALS A MAGNIFICATION FACTOR OF 1.17.

23. WAYS TO DECREASE MAGNIFICATION
IF OID IS INCREASED?
INCREASE SID!
CHEST
LATERAL AND OBLIQUE C-SPINE

24. DISTORTION Foreshortening
Object at an angle and CR is perpendicular to the part that is angled-trauma elbow
Spatial
Tube is angled to separate body parts
Clavicle
Elongation
object is parallel but tube is angled
sigmoid

25. FOG LEVEL/CONTRAST AND THE PROCESSOR
As time extends in the developing process the fog level____(toe of the characteristic curve) and the contrast____
increases
decreases

26. 90 seconds is the optimal developer time
A variation of 5 seconds either way can affect quality of film.

27. Developer temperature
As the temperature increases the fog level______
increases
optimum temperature is usually 90 degrees F.

28. SUBJECT CONTRAST Review:
Rad. Contrast=film contrast plus subject contrast
film contrast is controlled latitude of film, and processing factors

29. Subject contrast Patient (Size) Tissue (KUB)
Atomic # ( higher produces high contrast)
object shape

30. MOTION
PATIENT
TUBE MOVEMENT
TOMOGRAPHY

31. MOTION LARGE SID = LESS FOCAL SPOT BLUR
SMALL SID = MORE FOCAL SPOT BLUR

32. FOCAL SPOT BLUR

33. KVP GIVES ELECTRONS ENERGY TO HIT THE ANODE
HIGH AMOUNT OF KINECTIC ENERGY IN AN ELECTRON PRODUCES A HIGHLY ENERGIZED X-RAY PHOTON
BETTER PENETRATION=LOTS OF GRAYS

34. KVP LOW KVP PRODUCES A BLACK AND WHITE IMAGE.
TO PRODUCE AN ADEQUATE OD MUST USE HIGHER MAS
HIGHER MAS MEANS MORE EXPOSURE TO THE PATIENT

35. HIGH KVP HIGH MAS +Greater margin of error +Reduction in patient dose
+Wider latitude
-increase scatter
-increase fog
+Higher OD
+Lower Rad noise
-increased pt. Exposure
-less margin of error

36. The Radiographer controls
kVp
mAs
focal spot size
distance
added filtration
screen speed

37. REMEMBER
200 mA increased to 300mA is a 50% increase in electrons being produced
As mA increases, time must decrease to maintain same density
Distance Maintenance formula--New Sid over Old Sid Squared

38. REMEMBER Small mA station uses smaller focal spot
smaller focal spot = more detail
Inherent = .5 mm
additional 2 mm of aluminum between housing and collimator
collimator adds 1 mm