How To Make Sure Your Receptors Fit, the First Time and Every Time
Ever bought a big-screen TV, only to get it home and realize it’s not as big as you expected? TV screens, unlike almost everything else in the world, are measured diagonally, which is the biggest measurement on a rectangle. It’s a sales gimmick.
There’s a similar situation in the imaging receptor field. It’s not quite a gimmick, but it can be the source of costly errors and a lot of lost time. Mistakes happen because some products are sometimes named by their image-field size, and some by their true external dimension, which includes the image receptor. It’s important that end-users are speaking the same language as manufacturers.
Medical devices are one of many highly regulated products sold on the global market.
Every major-market country has some regulatory group or agency tasked to oversee pre-market and post-market aspects of medical devices, like the U.S. Food and Drug Administration. Many regulators use standards as a key part of their regulatory approval process.
Regulations are essentially the “what.” They define using such terms as “safe and effective.” Regulations are required.
Standards are the “how.” That is, how a manufacturer demonstrates that they meet the “what” of the regulations. Standards are (mostly) voluntary.
Is there overlap? Yes, no question. There is not always a clear line between “what” and “how.” There are always some local conventions to be accommodated.
In this country, the American National Standards Institute (ANSI) is the administrator and coordinator of the private sector voluntary standardization system. Founded in 1918 by five engineering societies and three government agencies, the Institute remains a private, nonprofit membership organization. ANSI standards are considered among the highest in the world.
When it comes to image receptors, ANSI standards relate to the size of the image. So some manufacturers name their products by image size.
But imaging devices require a receptor. An image receptor captures the latent image after it passes through the body part. It’s contained in a frame or holder. Examples of image receptors are conventional cassettes, fluoroscopy, CR cassettes or DR panels. DR panel imaging receptors are expensive. End users do their best to find a balance between having a large imaging area and keeping weight and cost to a minimum.
Again, imaging receptors have a frame, like a cassette. Some use film for the latent image, while the most recent technology (DR) allows the image to be viewed quickly on a monitor right after the x-ray is done. In either case, the portable image receptor should be lightweight and rigid enough not to bend under a patient’s weight, all while allowing the maximum amount of primary radiation to reach the IR.
Captured images are then transmitted for reading or processing.
Because the size of the imaging area varies from the size of the device used to hold the image field, problems can arise when manufacturers list receptors for purchase by their imaging size, instead of their outside dimensions. The FDA regulations, and ANSI standards, refer to the outside dimensions of the imaging receptors. But the advertising of a product for sale by receptor size can fool an unwary buyer, if the outside dimensions do not follow the ANSI standards.
It’s like that big-screen TV.
External dimension measurements are not the same as the imaging area, and this can have an impact on the use of standard IR trays, as they may not fit without major changes to some of your most expensive equipment. There can also be problems translating between metric and English measurements.
Are you sure you are buying the right size? This is just one of the many reasons we at Reina prefer to talk to you before you purchase. We are available at all times, to help you make sure you order the right-sized parts, the first time.