The fundamental question facing most imaging departments is: How do I include General Radiography in my transition to a filmless future? Determining whether Storage Phosphor Imaging or future flat panels is the best alternative to take your department digital requires a thorough understanding of the technology behind the process, their respective advantages and disadvantages, and, importantly, the costs to delivering the quality and efficiency you demand.

Computed Radiography (CR) describes the process of bringing X-Ray technology into an enterprise-wide digital future. CR is a process, NOT a product. CR is an entire modality, not simply an acquisition device. CR should not be considered equal to flat panels. Computed radiography describes an entire process of creating a digital image. This includes the ability to Acquire, Process, Present and Manage the image data. Flat panels describe a developing image acquisition technology. Each acquisition technology has its own unique characteristics such as receptor properties, physical implementation and results.

Acquisition Technologies
Several technologies currently exist to acquire digital images in a General X-ray Environment.

• Storage Phosphor is a photostimulable phosphor plate that emits retained X-ray energy when stimulated by light.
• Amorphous Selenium plates create a charge pattern in the selenium layer from an exposure. This pattern is read out by a thin film transistor array or electrometer probes.
• Amorphous Silicon photodiodes read an electrical signal that is read out by a thin film transistor array. A scintillator must convert X-ray to light which then must be converted again to become an electrical signal for readout.

UNDERSTANDING THE TECHNOLOGY

With current acquisition technologies, taking your department to a filmless environment can provide better workflow than film, regardless of the acquisition technology. Utilizing Storage Phosphor as an acquisition technology provides several advantages to users.

Validation Advantage
Storage Phosphor has over 18 years of application experience and has been rigorously studied for its suitability. This experience allows Storage Phosphor to offer a wide range of validated exam protocols. Both Amorphous Selenium and Amorphous Silicon acquisition technologies still require established processing protocols as well as wide scale use for validation. One of the biggest hurdles facing flat panel technology is the issue of “dead pixels”. These are pixels that are dead and produce no imaging information. Manufacturers of these panels take imaging information from surrounding pixels and basically clone this information into the dead pixel area. Pixels on these panels can be “dead” when the panel is new, or may die throughout the life of the panel. It is conceivable that the panel could be bumped, jarred, or otherwise damaged, thereby killing the various pixels.

Portability Advantage
CR Readers can be used in conjunction with general X-ray equipment already in place. Storage Phosphor IP’s replace X-ray film so that remote equipment can still be utilized. CR Readers are durable, can be centrally located for increased access and can cover a broad range of applications: Amorphous Selenium/Silicon acquisition technologies are currently contained within radiographic equipment as a flat panel with fragile pieces that may be difficult to use in portable applications. Moving equipment presents a risk of breakage that can range in replacement costs from $50,000 -$70,000.

Cost Per X-ray Cabinet Advantage
Because Storage Phosphor IP’s can be used with an imaging department’s existing equipment, taking an entire department digital can be attained with the purchase of one CR Reader. Flat panel receptors using Amorphous Selenium (aSe) or Amorphous Silicon (aSi) equipment must be purchased for every X-ray room to make an imaging department filmless. Flat panels may be difficult to add to existing equipment. Creating a filmless department using flat panel acquisition technologies will require a substantially higher initial investment that current throughput predictions will not be able to cost justify. For a quantitative analysis, Storage Phosphor permits a lower cost when implementing a filmless environment.

Disadvantages exist for every form of digital acquisition technology
Taking an imaging department digital will require a user to realistically consider some compromises. Storage Phosphor, while increasing the efficiency of radiographic processing, requires one incremental workflow step in the delivery of an IP to the CR Reader but still improves efficiency over traditional X-ray film processing. Flat Panels eliminate that workflow step but create a higher cost per x-ray cabinet and makes portable imaging problematic. The user must determine whether the additional expense is worth eliminating one workflow step.

FUTURE OF DIGITAL ACQUISITION TECHNOLOGY?

Storage Phosphor will be the predominant acquisition method of digital x-ray for the next decade. Future imaging departments will likely utilize several different technologies together. The nature of flat panels will encourage continued use of Storage Phosphor in all applications.

Rates of Growth
Storage Phosphor is currently the only viable total departmental solution to take X-ray to a digital future. Amorphous Selenium and Amorphous Silicon will play a role only when the imaging department has a need for a new radiography or x-ray cabinet. In this respect, flat panels will be implemented only when there is an equipment replacement demand. With significant growth of the Digital market, Storage Phosphor demand will grow at a rapid parallel rate as institutions reach a total digital solution for the 70% of its radiographic exams

QUANTITATIVE ANALYSIS

Digital X-Ray Cost Per X-ray cabinet
It is anticipated that cost of CR and flat panels will decrease over the next five years. In 2001, a flat panel detector is priced at approximately $200,000 per cabinet, serving only this cabinet. By 2003, one might see the price as low as $150,000. In 2001, a Fuji CR is priced at approximately $100,000 per cabinet, with the capability to service 2-3 cabinets. Five years later, the expected price of acquisition might be $75,000.

$185,600 Incremental Expenditure Per Room

Typical Amoritization Schedule for Imaging Capital Equipment is 5 Years.