Once you've made the decision to convert your analog X-ray system into a fully digital X-ray system, you'll find yourself looking out across a wide field of options to make that choice happen. The number of companies manufacturing digital X-ray detector panels has increased dramatically in the last few years and, as you might suspect, each of them goes about it in their own way and leverages their product's strengths against those of their competitors.
To help you "decode" some of the jargon on what is likely your first purchase of this type of product and narrow down the field of options, we've put together a briefing on the aspects of DR panels that make the biggest practical differences. Our hope is that you can hit the panel market better informed and, maybe, a little less hung up on some of the minutiae.
Panel Size and Configuration
DR Panel manufacturers offer panels in 14" x 17" for the table bucky and 17" x 17" for the wall-mounted bucky. In high-volume facilities, a fixed panel in the wall bucky used in combination with a wireless panel in the table is a sound way to maximize efficiency. In a lower-volume setting, a single tethered panel can be easily moved from the wall bucky to the table and still have a dramatic impact on workflow over film or CR processing.
Initially, DR panels were charge coupling device (CCD) technology. CCD was a big first step forward from film in image quality and processing speed. CCD has since given way to amorphous silicon with thin film transistors (TFTs). These detectors are lighter than CCD models with even higher image quality and are more frequently available in portable, wireless configurations. CCD panels are still available and cheap, but have been far surpassed in quality and convenience.
Amorphous silicon DR detectors use either CsI (cesium iodide) or GOS (gadolinium oxysulfide/ gadox) as their scintillators- the material layer that converts X-ray energy into perceptible light. Both types of scintillators are currently offered by several manufacturers. CsI allows for a lower exposure during image acquisition. Because of this, CsI panels were initially offered at significantly higher prices. Over the past few years, however, the price gap between CsI and Gadox has narrowed.
Manufacturers have responded to the need for automatic exposure detection (AED) by introducing automatic trigger modes on many panels. This allows the DR panel to capture an image without integration with the generator. This significantly reduces the work, time, and overall fuss of installing a DR panel as an upgrade from film or CR as the panel will detect incoming X-ray and turn itself on instead of receiving instructions from the generator. AED cycle time is a function of how fast the panel can be ready to capture another image. There are panels currently available that are ready to capture images every half second.
Pixel Pitch and Resolution
Pixel Pitch is a measurement of the distance between the individual pixels in an X-ray grid. Generally speaking, a lower number equates to a better picture, however, with imaging detectors there is a possibility that pixel receptors can be crowded too closely. This results in lower image quality due to light bleed. For example, a pixel that should be dark might appear as faint white due to light bleeding over from an adjacent pixel. The best thing to do is to look at real images from any panel you consider and find the "happy medium".
Resolution is the term that refers to the number of line pairs per millimeter (LP/mm), that is, how close lines can be to one another and still be visibly distinguishable. As the LP/mm increases, so does the image quality.
DR panels have two main battery types: fixed and removable. A fixed battery is built into the panel. When it needs a charge, the panel is either taken to the charger and plugged in, or a charging cable is stretched out to meet the panel as it sits in the bucky tray.
Removable batteries can be used more like those you'd find on a cordless drill. When a battery is in need of a charge, you can pull it out of the panel, place it on the charger, and rotate in a fresh battery.
You probably won't find a single panel that's the "best" in all of these areas AND for your budget, but there are plenty of options out there that strike a reasonable balance. Besides, they're all improvements over the film and CR technology of the past.
If you have still more questions about DR panels, we have more resources for you below. You can also contact us to talk to an X-ray Product Specialist about your project.