Digital Imaging in the Hospital

Digital Imaging in the Hospital Radiology Department

The Evolution of Digital Imaging

Digital imaging in hospital radiology departments came about for several reasons. The most important of these, however, was the idea that the digital images could be viewed by any authorized person at any time, thus making it much easier and faster for those that needed to see them to have access to these images (Gillespie, 1999). These digital images eliminate the need for films and film libraries, thus freeing up space, as well. However, there are still problems with this issue that have stopped digital imaging in hospital radiology departments from progressing and growing as fast as was hoped. The major concern for these departments is the cost that is incurred when it comes to the digital imaging equipment, which is much more expensive than the older methods that were previously used to take x-rays and perform other functions (Gillespie, 1999).

The hoped-for return on investment has not been seen in many of these departments, and this makes these same departments slow to transfer over to a filmless system. When coupled with the cost of the technology, digital imaging has been relatively slow to evolve, but its importance for the future should not be discounted. Despite its slower-than-expected start, however, studies and other evidence show that the use of digital imaging in radiology departments and other areas of medical practice is growing (Zesearch, 2001; Newman, 2003; Revolution, 2003). Naturally, larger hospitals and departments are able to more easily afford this kind of technology, and therefore they are usually the ones that expand more quickly and use the latest technology, but other, smaller hospitals are also showing interest in digital imaging for their radiology departments if they are able to find funding for the initial purchase of the equipment that they need.

There are two main types of systems - computed radiography (CR) and digital radiography (DR). The rest of the paper will devote itself to a discussion of these two types of digital imaging systems as they relate to hospital radiology departments, followed by a discussion of image quality and its significance.

Computed Radiography (CR)

Both computed radiography and digital radiography are significant to this field, but there are differences between the two that need to be discussed. One of the main issues with CR is that the density and other issues that are necessary to get a high-quality image are not the same as they were with other systems in the past (Cesar, 1997). This can leave radiographers feeling frustrated, and some hospitals are already having difficulty keeping enough radiographers and getting people interested in this field. Some of this reluctance on the part of others comes from the issues related to CR.

Individuals who are trained in diagnostic radiography and other issues such as CT scans or mammograms are typically paid more and find employment easier than individuals who know only one of these skills. It is becoming increasing important to keep up with new technology as much as possible when working in the radiology field. Despite the need for more radiologists, however, few people turn to this career path. Some of this is thought to be because of the lack of funding for the quality equipment that is often needed and therefore the frustration that is felt by those that are simply trying to do their jobs and finding little satisfaction in them.

Prototypes of today's machines used for CR were installed in some hospitals in the early 1980s, but there have been many changes since then, most notably the portability of the machines (Moehring, 1997). There are also many different companies that make CR equipment, including Fuji (Fujifilm, 2002) and Kodak (Kodak, 2003). These two companies are among the top competitors and marketers when it comes to CR technology, and they are generally considered to be among the best where quality is concerned, as well. For example, Kodak (2003) made the following announcements, reproduced here verbatim, about what their new imaging technology could do:

Here is a summary of Kodak's announcements:

Kodak DirectView PACS System 5 architecture, which is currently under development, will expedite the efficient storage, reading and review of radiology reports and imaging studies. It will scale to support a small hospital, one or more imaging centers or a large health care facility. The Kodak DirectView Web Distribution System provides a foundation for the transition to the new Kodak DirectView PACS System 5 architecture. Kodak's well-developed migration path includes a series of upgrades designed to leverage customers' existing PACS equipment.

Kodak DirectView Web Distribution System, which distributes imaging studies and radiology reports to referring physicians using the Internet, includes the new database that will be used with PACS System 5 architecture and presents new and existing customers with the opportunity to begin migration. The Web system supports clinical review by physicians on dual-monitor, high-resolution workstations; provides both lossless and lossy (wavelet) compression; and supports both Macintosh and PC platforms using an Internet Explorer or Netscape browser.

Kodak DirectView CR 950 system, being demonstrated for the first time at ECR, supports the productivity needs of busy radiology departments and clinics by processing up to 81 plates (35 x 43 cm) per hour and accepting eight cassettes at a time. In addition to faster processing speeds, the start/pause button is located on the device, so that a technologist can load cassettes while another technologist is entering information at the workstation.

Kodak DirectView CR 850 System is a single-cassette system that offers throughput of up to 103 cassettes an hour. In addition to offering exceptional image quality and ease of use, the speed of the CR 850 system can improve technologists' productivity and patient throughput in a variety of environments. The CR 850 system's all-in-one design offers a footprint of just 63 x 73 cm, which is ideal for ER, ICU and other areas with limited floor space.

Kodak DirectView CR Long-Length Imaging System, a digital image capture system that includes a wall-mounted vertical cassette holder, provides hospitals and diagnostic imaging centers with digital image capture of full leg and full spine images. Kodak's fully automatic stitching software delivers images of up to 43 x 129 cm that can be viewed in softcopy or printed onto radiographic film. This system significantly reduces the most frequent causes of exam retakes, which are poor stitching, incorrect alignment or images that are not in the right order.

Kodak DryView 8900 Laser Imager, the new flagship product in Kodak's dry laser imaging line, produces more than 180 films per hour at 650 dpi (dots per inch) laser resolution. This exceptional resolution applies to all film sizes, including 35 x 43 cm and 35 x 35 cm. This is a significant advantage over other imagers that print at high resolution only on smaller film sizes, and at slower speeds. The imager contains three film drawers and supports five film sizes. The imager's ability to place any film size in any drawer makes it an excellent choice for centralized printing in busy multi-modality areas.

Kodak DirectView DR 5100 System, a digital radiography system for the direct digital capture of images. The system is built on a compact platform that includes: a new integrated touch-screen operator console, a new generator, bucky and tube stand, and Kodak DirectView PTS software (Kodak, 2003).

It is clearly amazing what Kodak (2003) has accomplished, but other companies are also doing amazing things when it comes to what direction digital imaging is taking in the radiology departments of hospitals. While CR is important, digital radiography, or DR, is also very significant, and must be discussed as well.

Digital Radiography (DR)

Digital Radiography (DR) is even more cutting-edge than CR, since it allows for the digitized enhancement and adjustment of images, for issues such as density, contrast, and others (Daniels, 1998). In some fields, such as dentistry, there is DR technology that is also wireless (Schick, 2003). This is the next big step for DR, and it seems as though this type of wireless technology will soon make its way into many hospitals and their radiology departments, simply because of the fact that it is so much more convenient. Another important advantage of DR, whether wireless or not, is that the patient is not exposed to as much radiation, thereby lessening the chances that the exposure could cause damage or health problems of any kind (West, 1997). Naturally, this is very significant for the patients that are treated in radiology departments in hospitals throughout the world.

Even veterinarians are using the technology to help with their larger animals, such as horses (World, 2004). This would indicate a growing interest in DR in many different fields of medicine, which would help to brighten its future considerably and put it on the road to total acceptance in the future. This acceptance may not come that quickly, however, but not because of any kind of quality problems with DR. Instead, the lack of acceptance, or at least the lack of use, may come from the fact that DR is very expensive. It uses a great deal of expensive and cutting-edge technology, and none of this is cheap. While DR can do a great deal for a hospital radiology department, that department also must have the funds available to support what needs to be purchased and accomplished where DR is concerned if the department chooses to use this technology.

Image Quality

Image quality, other than cost, is quite probably the largest issue that is faced by those that wish to use this new technology. Therefore, it is important to discuss and compare the differences between the image quality of CR and the image quality of DR, so that more can be understood regarding the differences between them. One study looked at the plate readers that are used for CR images, and found that there were enough statistically significant differences between different plate readers as to indicate that there may be problems with the accuracy of the data and the quality of the image at times (Quinn, 2002). Digital radiography (DR), without question, has the better images, but it is also much more expensive than traditional film, so many companies are going for a compromise of quality and cost, which leads them to CR, since the images are still good quality and the technology is significantly less costly than DR (Demonstrated, 2004).