Panoramic Corporation - Panoramic X-Ray Machines and Accessories

IMAGING PHYSICS
Panoramic and cephalometric X-ray units use cassettes with intensifying screens to expose images on X-ray film. The film is extremely light sensitive and the intensifying screens are made of a phosphorescent material that emits light when struck by radiation. The amount of dense matter the X-ray beam strikes as it passes through the patient’s head determines the level of light produced by the intensifying screens.

The film and intensifying screens must match so the spectrum of light the screens produce is the same spectrum of light the film is sensitive to. There are two primary types of film and screen combinations - blue and green (or rare earth).

Blue sensitive film/screen combinations have a system speed of 200. The blue intensifying screens are X-Omat by Kodak. These screens require blue sensitive film, such as Kodak DF-76.

Green film/screen combinations have a system speed of 400. The advantage of a 400 speed combination is that it requires half as much radiation to produce light picked up by the film. This is twice as fast as the 200 speed film. These intensifying screens are Lanex and require Kodak T-Mat G film.

X-ray units that have the 200 speed film/screen combination can be upgraded to the 400 speed system by adding a beam filter kit, Lanex screens and T-Mat G film. The beam filter kit reduces the amount of radiation emitted to the screens by half. Please refer to the following chart for proper film/screen combinations.

Size	Intensifying Screens	Film	Speed	Results
Panoramic	Kodak X-Omat Regular (blue sensitive)	X-Omat RP DF-76	200	High Contrast Manual & Automatic Processing
Panoramic	Kodak Lanex Regular	T-Mat G (green sensitive)	400	Excellent Detail, High Contrast
Panoramic	Kodak Lanex Regular (green sensitive)	T-Mat H	800	Very Good Detail, High Contrast, Two Sheets Can Be Exposed At Once To Produce Two Originals
Cephalometric	Kodak Lanex Regular	T-Mat G (green sensitive)	400	Excellent Detail, High Contrast
Cephalometric	Kodak Lanex Regular (green sensitive)	T-Mat H	800	Very Good Detail, High Contrast, Two Sheets Can Be Exposed At Once To Produce Two Originals

STATIC/CLEANING/CARE
Intensifying screens have a life expectancy of approximately five years. The amount of light that the phosphorescent material produces decreases over time and with use. If your films are becoming slightly lighter or have lost their definition, it could be a result of the screens not being able to produce sufficient light to expose the film. If your machine has been installed for more than five years, it may be time to purchase new screens.

Intensifying screens have a life expectancy of approximately five years. Dirty or cracked screens also produce a poorer radiographs. Cleansing periodically with Kodak Antistatic and Screen Cleaner or mild soapy water should take care of most dirt that may accumulate on the screens. Because the screens are porous, some stains such as developer solution cannot be removed and will result in areas that are lighter on the developed film. Cracked screens cannot be repaired and should be replaced.

In a climate where dryer conditions are present or in the wintertime when there is less moisture in the air, static can become a problem. Clean the screens with a Kodak Antistatic and Screen Cleaner or mild soapy water to add moisture to the screens. If static is still present, wiping the inside of the cassette sleeve with a damp towel also decreases the static within the cassette sleeve. Depending on the office climate, this procedure may have to be done more than once a week.