Purchasing a digital radiography system can be a daunting task. Considerations such as service and support, detector technology, image quality, software functionality, PACS, DICOM, backup and practice management integration are topics that must be considered at some point in the purchase. The trick is to avoid becoming overwhelmed and to approach the purchase systematically. In my pre-purchase consultation service with veterinarians, the starting point for discussion is which type of detector technology is appropriate for their practices. The two main types of detector technology are computed radiography [CR] and direct digital radiography [DR]. Step 1: Is CR appropriate for your practice? CR uses imaging plates to generate a digital image. These imaging plates are placed in a CR reader, which generates a digital image. The workflow has a similar feel to film-based systems. Despite claims to the contrary made by some DR vendors, most veterinarians choosing CR will see some degree of time savings and increased efficiency in radiology. The image quality from CR systems is equal to or superior to many DR systems. It is this author’s opinion that for pocket pets and exotics, CR systems may perform better than many DR systems. CR is a mature technology and large corporations make many of the CR scanners. The same systems are used in the human health space. One side benefit of this crossover is that these companies guarantee support of the software and hardware for at least seven years if the companies stop production of a given model of CR machine. CR offers these benefits at a cost lower than DR systems. Top-quality CR systems can be installed for under $40,000 to $45,000. The mature technology, image quality and hedge against the future provided by the large companies backing these systems make CR a no-brainer for any smaller veterinary practice, particularly if it does not need a new X-ray machine. CR machines are sold by national corporations, national veterinary supply distributors and local X-ray distributors. Prices, packages and support vary with the distributor. It is our experience and the experience of our clients that when purchasing a CR system, the support provided by the local or national distributor is as important as the CR system that is purchased. Step 2: If CR is inappropriate for your situation, what type of direct digital radiography will you purchase? DR systems have a feel like the digital camera on your cell phone. As soon as you take the image, it appears on the computer monitor—there is no processing step. The main benefit of DR, therefore, is the speed of image generation and the potential for increased throughput through the radiology room. There are two competing types of DR systems in the veterinary market: charge couple device [CCD] cameras and flat-panel detectors [FPD]. CCD-based DR: CCD is the newest player on the veterinary digital landscape. In the past, CCD systems were of poor quality. As such, CCD has gotten a bad rap in veterinary digital radiography. In the past, complaints about older CCD systems and low-end systems dealt with image quality, dose and exposure latitude. Low-end CCD cameras now sold on the veterinary market continue to suffer from these limitations. Conversely, as was demonstrated at this year’s Digital Showdown (see AnimalInsides.com), the image quality and doses used to obtain these images from modern CCD cameras can rival flat-panel detector systems. Many veterinarians in the market for a digital system are buying digital radiography systems because they need a new X-ray machine. These veterinarians find CCD attractive because most CCD cameras are sold as a detector/CCD camera combination that is just a bit more expensive than a CR machine plus a new X-ray machine. CCD systems are sold through local X-ray distributors, national distributors and national veterinary equipment distributors. The long-term costs of a CCD system may be less than a flat-panel DR because these CCD systems are sold with attractively priced service contracts. As with all digital systems, local service and remote service will become important eventually and a service contact is only as good as the service provided with the contract. Be sure you are buying from a company with a proven track record. Companies selling CCD systems seem to come and go these days. Flat-panel DR: Flat panel DR is the type of DR system most commonly found in human hospitals and large veterinary institutions. The image quality from flat-panel DR systems varies between vendors but is generally considered to be of high quality throughout this class of detector. Flat-panel detectors are easily retrofit to existing X-ray tables and are often the DR system of choice for veterinarians who do not need a new X-ray table. Traditionally, flat-panel detectors have been out of the price range for many veterinarians. Recently, however, we have seen an influx of new panels on the market and the price likely will soon rival many CCD-based systems. Veterinarians considering an FPD DR should consider the long-term costs of ownership. Many of these panels require expensive service contracts. The service contract is strongly recommended with all FPD DR systems as these plates do fail and must be replaced. Without a service contract you will be purchasing a new system. FPD DR systems are generally sold directly by national veterinary companies. In the near future, however, we expect to see flat-panel detectors sold through local X-ray distributors. As I have recommended previously, the local service is as important as the DR system you purchase. The bottom line in this discussion is that no single technology is correct in every situation. Most veterinary hospitals that do not need an X-ray machine will find that CR is a great value. For veterinarians who “need the speed,” DR systems are more appropriate. CCD can be a great value for clinics that need a new X-ray machine in addition to a DR system. Flat-panel detectors use a proven technology that is also commonly used in human hospitals and many large veterinary institutions. Matthew Wright, DVM, MS, Dipl. ACVR, is a veterinary radiologist working with AnimalInsides.com. This article first appeared in the January 2010 issue of Veterinary Practice News.
