What is the single most important thing you can do to improve image quality on radiographs? Collimate! This is by far the simplest, cheapest, and perhaps most important thing you can do to improve x-ray quality and reduce patient exposure.
The most prevalent mistake I see doctors make in radiography is either failure to collimate at all, or failure to collimate enough. In almost all instances the size of the x-ray field should be less than the size of the film by one inch or more, in some instances, much more.
Reducing the body area being radiographed, by tighter collimation, reduces the amount of x-ray photons that interact with, and thus ionize, body tissues and organs. A reduced number of x-ray photons interacting with matter means less scatter radiation, and this in turn means a truer image with higher contrast. Even large patients can be radiographed with good results. One thing that is very important to remember is that because you have reduced the scatter (which normally accounts for a good deal of the blackness of the film), your films will turn out lighter unless you increase the mAs to compensate. Remember, longer exposure times can result in recorded patient motion (blurring artifact). Another important tip along these lines is: never change the kVp to modify density.
On to another subject: how should you care for your cassettes and screens? Rare earth intensifying screens are the only type of screen that should be in use today. If you are still using par speed screens made of calcium tungstate, you need new screens.
The projected life span of well-cared-for radiographic screens is about seven years. Failure to take care of them can result in damage that renders them worthless in a matter of months. I see screens in use that are 10 to 15 years old. They are usually scratched, chipped, warped, some have stains on them from spilled chemicals, and a surprising number have mold growing on them. Intensifying screens are very expensive. Thus, their proper care is paramount.
Screens should be cleaned according to manufacturer's specifications. Some can be cleaned with a mild solution of soap and water, others ethyl alcohol, others require anti-static preparations. If you don’t know which of these solutions to use, contact the screen maker (just look at the edge of one of your x-rays to determine who made the screen).
Once you know what to use to clean them, you should know that screens are very easily scratched. Use a soft cloth and a small amount of cleaning solution with care to avoid getting liquid over the edge of the screen where it can seep into the backing material and cause damage to the screen itself. Cassettes should be placed upright, like a book standing on its end, slightly open, in a dust free area until dry.
What do you do if your screens are old, moldy, and damaged? As I said, screens are very expensive. There are, however, ways around the expense. Some x-ray film companies will make a deal with you to supply your office with new screens and cassettes at reduced and sometimes no cost if you will enter into a film contract with them. In this contract, you agree to buy [good quality] film at a reasonable price over a period of three years or more. The discounted screens are a perk for entering into this contract. You should contact the company (i.e., DuPont, Kodak, etc.) directly first, not one of their resellers, to inquire about a deal.
Another option is to buy well-cared-for used screens from a hospital or imaging center. These facilities usually rotate equipment out on a regular basis, regardless of in how good condition they are. Prices are usually significantly lower than those for new merchandise.