Image Processing and Quality Assurance
Class 2
Gurney Mott Theory
•	Developed in 1938 and remains unchallenged today
•	Incident photon frees electrons that deposit at the sensitivity speck then attract silver ions
•	At least 3 ions must be deposited for visible blackness to be seen after processing
•	The more silver ions that are collected at the sensitivity speck = the darker the film
Film Storage and Handling
•	Attention given to age, heat, humidity, light, radiation and handling
•	Expiration date on box- use older film first
•	Storage temperature should be 68O or lower. Cold temperatures keep film longer 
•	Humidity should be maintained between 30-60%
•	Keep in lead lined area to prevent radiation exposure
•	Films should be stored on end like a book to prevent pressure artifacts
•	Abrasion artifacts occur from fast movement under pressure
•	Quick movement causes static on films
•	Chemical fumes can cause film fog
Cassette Loading
•	Grab only by the corner
•	Gently place it in the cassette
•	Touch film as little as possible

Image Identification
•	1. methods 
–	Lead markers 
–	Film flashers
–	Film punches
–	Data input on computer
•	2. legal considerations
–	Name 
–	Facility
–	Date
–	Physician 
–	MR number
–	Exam ordered
–	Tech’s initials are used with lead letters on film and indicate L R  or upright
–	Info written with “sharpie” or a sticker covering wrong information will not hold up in court.

The correct way to fix a film with the wrong ID is to repeat the film BOARD ANSWER

Real world?????????

Automatic Film Processor
Components
•	Developer 
–	develops film
–	Temperature is 95O

•	Fixer 
–	Stops development and prepares for archiving

•	Wash 
–	Removes chemicals
–	Water

•	Dryer
–	Dries film
–	Uses hot air 120O

5 Processor Systems
•	Transport
•	Dryer 
•	Replenishment
•	Circulation
•	Temperature

Transport System
•	Moves film through processor
•	Controls length of time the film is in the chemicals
•	Agitates chemicals
 
•	3 sub-systems of transport
–	Transport racks
–	Crossover networks
–	Drive system
Transport racks (1)
•	Rollers move films through
•	The turnaround turns films at the bottom of the tank
–	Made of three parts
–	Master roller (solar roller)
–	Planetary rollers
–	Guide shoes (ribbed to prevent sticking)
Crossover Network (2)
•	Moves film from one tank to the next
Drive System (3)
•	Made up of mechanical device with pulleys and gears to move the rollers

•	Entrance rollers- special rollers. Designed to grip film. This is also where the micro switch for replenishment is located.
•	Tray has guides on side to align film. You should alternate sides to prevent wear on one side
•	****** short edge of film against guides to save on chemicals
Replenishment
•	Replaces chemicals that are used or evaporate
•	It is activated when a film enters the processor
•	The entrance rollers activate a micro switch that controls replenishment
•	Replenishment is dependent on the size of film. Ex 14x17 replenishes more than a 8x10
•	Stand by switch will put processor to sleep when it has not been used for a period of time
Circulation
•	Stabilize temperature 
•	Agitate solutions
•	Mix chemistry
•	Separate circulation system for each tank but powered by same motor
Temperature System
•	Maintains all solutions
•	Developer temperature is 92-96o (95o for 90 second processor)
•	Changes of .5o can show visible change = dark
•	An increase in temperature will result in a decrease in time

Maintenance
•	Start up and shut down procedure
–	 Close lid, turn on processor, turn on water, run film through

•	Removal and cleaning of crossover assembly 
–	Mostly done by maintenance, must not contaminate developer with fixer. Developer can go in fixer but not the other way. 

•	Sensitometric monitoring
–	 the films response to exposure. 

System Malfunction
•	Observable effects and possible causes 
•	Film stuck makes noise
•	Film artifacts can be caused by rollers, guide shoes, ect
•	Density and contrast changes are caused by chemicals and temp

Curtain Effect –solution dripping down
Guide shoe marks

Hyporetention

Crown static
Smudge static
Processing Digital/Electronic Images
•	Exposure indicator	- S number range

•	Acquisition- acquiring image in digital format

•	Data manipulation window level/ width and patient info
Image Archiving
•	(PACS) picture archival and communication system 
–	The ability to send images to offices, other hospitals, ect

•	Films- 
–	Archived for 5-7 years
–	Pediatric films till 18 y/o 
–	Mammo films forever!

Safelights
•	Radiographic film is NOT sensitive to specific wavelengths of orange-red light (laser film is)
•	Must indirectly illuminate work area. Reflect form the ceiling to work area. Mounted at 4 feet away
•	Bulbs will be 7-15 watts 
•	Switch for white light should be up high so it is not mistakenly turned on

Densitometer- An instrument that provides a read out of the amount of blackening on a film.  Read by the amount of light that gets through the film.
Sensitometer – designed to expose a reproducible uniform optical step wedge on film using light.