Darkroom and Film Processing Rad Tech A Week

Darkroom and Film Processing Rad Tech A – Week 9 Fall 2010

Darkroom

Darkrooms – Still Necessary? • Darkrooms are necessary for manually fed processors and daylight processors. -Loading automatic film processor magazines. • Necessary for conducting certain quality control tests (daily sensitometric strip).

Darkroom

Darkrooms 4 Basic Functions • Number 1 Function • Storage – Unexposed film

Film Bin

DARKROOM FUNCTION # 2 Purpose of Film Processing • Change silver halide crystals from film emulsion (after exposure to x-ray or light photons) to black metallic silver. • Latent image (invisible until processed) is developed into a Manifest image. • Improper or careless processing can cause poor diagnostic quality.

Manual Feed Processor

Hand Processing in the Early years • Strong smell of chemicals • Messy • Time consuming

1956 – first roller transport 6 minute processing time

Processing Time 3 minutes 90 seconds

Processing Film Table top Processors Can process as fast as 60 seconds TABLE TOP PROCESSOR

PROCSSING CHEMICALS n n Solutions are PRE- MIXED Outside Company usually provides servicel Weekly or monthly Solutions should be replenished as necessary & changed regularly Solutions must be monitored (Daily QC strip).

Replenishment tanks

TABLE TOP FILM DUPLICATOR to MAKE COPIES OF FILMS

WILL THIS WORK ? ?

Daylight Processor

Function # 3: Handling of Film

UNLOAD EXPOSED FILM

Function # 4: Film Identification • • • Pt name Exam date & time Pt x-ray number Pt Birthday/DOB Rt or Lt marker Optional – Exam type – Dr. Name

FILM ID PRINTER Name of patient place on top Cassette is “flashed” with name – can be done before or after image is taken Should be done BEFORE PROCESSING FILM

AUTOMATIC PROCESSING • TRANSPORTATION SYSTEM • DEVELOPER • FIXER • WASHER • DRYER • REPLENISHMENT SYSTEM

Automatic Processor

• http: //www. coursewareobjects. com/objects /mroimaging_v 1/mod 08 i/0845 a. htm

Processor Chemistry Overview • Developer – converts latent image into manifest image • Fixer – clear the film of unexposed, undeveloped silver bromide crystals, promotes archival quality • Wash – rid the film of residual chemicals

Wash • Rid the film of residual chemicals for developer and fixer • Residual chemicals on the film will discolor radiograph over time. • Cold water processors are less efficient in removing chemicals – Warm water processors much better. • Agitation during wash process is essential

Fixer Retention (Not Washed Off)

Transport System Components • Feed Tray • Rollers (Different Assemblies): 1. Entrance 2. Deep Racks 3. Turnaround 4. Crossover 5. Squeegee 6. Dryer • Receiving Bin

Transport System (Rollers) Feed Tray Entrance Deep Racks Turnarou nd Crossover Squeegee Dryer

Processor (Top View)

Replenishment System • Main function: Keep solution tanks full and assure proper solution concentration. • As film is introduced into processor, sensor initiates solution replenishment • Right & wrong way to feed in film -Feed in along short edge

Transport System in Automatic Processors • Conveys the film through different solutions (sections) by a series of rollers driven by gears, chains & sprockets. • Done at a prescribed speed – determines length of time the film is in each solution

Temperature Regulation • Main function: To control the temperature of each section of the processor. • Developer – most important solution to regulate • Usually between 92 degrees and 95 degrees • Thermostatically controlled

Recirculation System • Provides agitation necessary for uniform solution concentration

Wash & Dryer Systems • Wash: Provide thorough removal of chemical solutions from the film. -Archival film quality • Dryer: Removes water from film by blowing warm, dry air -Between 120 degrees & 130 degrees F.

Silver Recovery • About ½ of the film’s silver remains in the emulsion after exposure & processing. • Other ½ (unexposed silver) is removed from the film during fixing process. • Silver is toxic to public water supply – must have proper disposal.

What is in the Darkroom?

Darkroom Contents Loading Bench Film Bin Film I. D. Printer Safelights Pass Box Light-tight Room Ample ventilation Warning Light outside room Lockable Door Wall Shielding if adjacent to x-ray room Walls painted with light color to reflect safelight

Darkroom Equipment

Darkroom Equipment

Safe Light • 15 Watts • Red filter • Must be 3 -6 feet from counter top or feed tray of processor • Used to be amber or orange filter

Darkroom Summary

Summary & Questions