Evaluate Two Current Imaging Methods for Chest Radiography - Essay Example

Running Head: EVALUATE TWO CURRENT IMAGING METHODS FOR CHEST RADIOGRAPHY Evaluate two current Imaging Methods for Chest Radiography [The of the writer appears here] [The name of the institution appears here] Evaluate two current Imaging Methods for Chest Radiography Digital radiography was introduced in the Royal Adelaide Hospital in September 1997 to the Emergency and general areas of the hospital, and extended into the Intensive Care Unit (ICU) in October 1998. The images are viewed on a picture archiving and communication system (PACS) workstation where available, or a personal computer monitor. This research compares the latest digital radiography with the more conventional film-based counterpart in the clinical context. Digital radiography for X-rays and other forms of imaging has been shown to result in improved turnaround times to the requesting clinician. (Langlois, Le, Vytialingam & Aziz 1999) This usually results in more efficient patient management and better patient outcomes. The term "picture archiving and communication systems" (PACS) is used to describe the technologies that are eliminating film. Other terms that may reflect the PACS concept more accurately include "the film-less radiology department" and the "all-digital radiology department." The PACS concept is not new and, in fact, dates back to the 1950s, when Albert Jutras, MD, first conceived the idea of teleradiology . (Bronson 1998) The US government led the development of this technology, and the first film-less radiology departments in the United States were at military hospitals and the Veterans Administration Medical Centre in Baltimore. A decade ago, imaging studies performed by the military in the Middle East during Operation Desert Storm were transmitted digitally and interpreted by radiologists stationed in the United States. When used for radiology services, PACS must have images in digital format, be able to store them, and provide access for interpretation by radiologists and review by other physicians. (Huda & Szeverenyi 1999) Images often can be directly acquired in a digital format, but sometimes they must be converted to such a format. Familiar radiographic studies already available as digital data include computed tomography, magnetic resonance imaging, and ultrasound. In recent years, some traditionally film-based imaging techniques (eg, angiography, fluoroscopy, nuclear radiology) have also moved to digital image acquisition. One of the largest radiology components to convert to digital data is plain radiographs, such as traditional chest and bone films. Conversion can currently be accomplished through one of three technologies--use of a film digitizer, computed radiography, or digital radiography. The conventional radiography system involves cassettes, containing film, which are exposed to X-Rays at varying exposure levels. The cassette is fed into a daylight developing processor where the film is removed from the cassette and developed. The radiographers then check this developed image (The Hard copy), and if satisfactory the films are labelled, collated and then pigeon-holed for the clerical staff. The clerical staff retrieve old films for the patient, packet the combined films and manually deliver them to the reporting radiologists. The digital radiology system employs a cassette; similar to conventional radiography, but that is where the similarity ends. The digital cassette contains a reusable intensifying screen that uses photo-stimulable storage phosphors that can retain a latent image. The cassette is electronically tagged with the patient's information and is then processed in a digitizer. There is an observation monitor by the digitizer for the radiographers to check the image acquired. The image is then sent to the radiographer's workstation when post-processing of the image can be undertaken if required. This may involve adjustment of contrast or labelling of the image or, more usually, nothing at all, due to the software of the system which automatically optimizes the density of the image. (Blurne & Kurniya 1987) Once satisfied the radiographer sends the image over the network to the local workstation present in the radiologist's reporting room. Once the imaging data are acquired, they must be archived in a secure and easily accessible system. Storage procedures depend on the amount of data stored and on how rapidly information must be retrieved. For data that are needed quickly, such as studies that were recently performed or have not been interpreted, conventional hard drives or collections of magnetic storage disks can be used for rapid access. Optical disks and tape and digital tape work well for more permanent storage. Technology in this area is advancing at such a rapid pace that storage media are likely to change often. (Marchese 1998) A local digital network capable of handling large volumes of data quickly and securely is also required. Because the amount of data being transferred is so large (eg, 10 megabytes for a typical chest radiograph), the radiology network should be separate from the main institutional network to ensure reliability and performance of both systems. A computerized information system is needed to track and manage imaging studies, reports, and related demographic information. Such systems are already in place in many institutions under such names as "hospital information systems" or "radiology information systems." In the film-less radiology department, review of images takes place at viewing stations that provide various levels of radiograph quality, depending on the needs of the viewer. Images available at diagnostic workstations are of the highest quality and are used for final and official interpretation. By comparison, clinical workstations located in convenient areas throughout the clinic, hospital, and emergency department provide images that are not of diagnostic quality but are valuable for review and comparison. Depending on the needs of the institution, images may also be viewed through an organization's intranet services, using a Web browser. These images are of lower quality technically but can be made available on any network computer in the institution. They are particularly useful for patient education and consultation; differences in quality between diagnostic workstation and Web browser formats are not readily apparent to most observers. As with all changes in the delivery of healthcare, PACS have advantages and disadvantages. Advantages are both tangible and intangible and revolve around cost, increased efficiency, and improved patient care. The tangible benefits are most easily understood by accountants and hospital administrators. However, in the long run the intangible benefits probably represent the greatest advantage and are most easily understood by busy practicing physicians. Tangible benefits of a film-less radiology department include cost savings related to decreased use of film and less money spent for processing, storage, and handling. Some institutions have found that PACS have led to increased productivity of both technologists and radiologists. These factors could lead to substantially lower expense. Intangible benefits primarily involve increased efficiency and improved patient care. PACS allow immediate access to imaging studies by attending physicians, consultants, and radiologists--simultaneously. With this system, images can be available at the patient's bedside, in the physician's office, or even at the physician's home. This greatly reduces the amount of time needed to track down imaging studies. Theoretically, at least, lost imaging studies can be eliminated. Patient care is improved by avoiding the well-known problems of misplaced films in emergent and critical care settings and the inability of several patient care teams to review images at the same time. Some centres have found that PACS improve the quality of image interpretation and reporting. With large archives of images readily accessible, radiologists more often compare a current study with previous ones. These factors are prompting many institutions to consider moving from a film-based radiology system to PACS. First among the disadvantages of PACS is equipment cost. Although the initial investment is daunting, it often can be justified in the long term because of increases in productivity and other benefits. Up-front costs of PACS have fallen considerably over the past few years and are likely to continue to decline as advances are made in computer technology. The initial expense can be minimized through a phased approach that involves replacing the older, conventional radiographic equipment that breaks down or becomes obsolete with PACS-compatible equipment. As with any major systems change, the transition period may be difficult. During the shift, both conventional and digital techniques must operate simultaneously. Workload is likely to increase because of the need to digitize plain films for archiving and comparison and to review plain films at a traditional view box but interpret digital studies at a PACS computer monitor. Another inevitable disadvantage involves the potential for system failure. No system, including conventional methods, is flawless or immune to malfunctions. Although PACS problems may be more apparent to the user, conventional radiology departments also face many opportunities for breakdowns in systems, albeit less visible ones. A tendency for less interaction among radiologists and other physicians in institutions using PACS is another potential disadvantage. This decline may arise because multiple viewing stations around a clinic or hospital reduce the likelihood that physicians will visit the radiology department. In turn, this reduces the opportunities for one-on-one consultation. Change is also a disadvantage and is always difficult. Many physicians and radiologists are reluctant to give up the "feel" of film. In general, younger generations seem to be more at ease with and more accepting of the digital format. There is a consistent trend for much more rapid availability to the requesting clinician of digital images compared to conventional images. This can be extrapolated to total cost savings due to more rapid implementation of treatment or discharge of patients. In his study on digital X-ray systems, Strickland (1999) felt PACS allowed 'real-time radiology', enabling significant cost benefit. As soon as images are archived, they appear on the monitor stationed in the requesting department. This means that the requesting clinician need not even leave their department in order to view the radiographs of their patients, whereas they must view conventional films in the X-ray department, or await their arrival in their own department, a further time consideration. Watkins et al. (2000) described time advantages where PACS significantly reduced the time between request and image availability in ICU for routine X-rays. It has been noted that a significantly higher number of repeated images are required for the conventional radiography patients compared to the digital patients (7:1). The digital image intensity modifying options, as well as the automatic adjustment for exposure of the digitizer seem to result in a greatly reduced requirement for repeated images in digital radiography. It is still current protocol to produce an 18 24 cm hard-copy film of all archived digital images, which the radiologists use to report. Lai and Langlois (1999) found there was a 30% reduction in reporting time for digital images compared to conventional methods. The results of clinicians' comparison of digital and conventional radiography are of great interest. Anecdotally, one finds many clinicians who are either avid proponents or opponents of digital radiography, mostly proponents. The reality is that PACS is now seen as part of a full Electronic Patient Record system. (Foord 1999) The Intensive Care staff responds more favourably towards digital radiography than the Emergency staff. Two studies dealing specifically with pulmonary abnormalities revealed no significant difference between digital chest radiographs and conventional film-screen chest radiographs, except for a lesser ability to detect subtle pneumothoraces when viewing digital examinations on electronic viewing consoles (Elam et al. 1992; Thaete et al. 1994) Opinion is still proffered by emergency physicians. It was expected that the image modifying options would prove useful to clinicians. In a similar study by Watkins, all staff said that they preferred PACS to the previous, conventional radiology service. (Watkins 1999) This is an often remarked feature of the digital system, especially the ability to magnify sections of images with great clarity. The image inversion feature seems especially valued for rib lesions or fractures. Conclusion Clinician satisfaction with the digital and conventional X-ray groups are comparable, but with the image modification options available with digital images being particularly valued. Comforting as it may be to hold an x-ray film in your hand and snap it smartly onto a view box, film technology seems destined to soon fade away. Films are already being replaced by digital images that are processed and stored electronically and retrieved and viewed on computer monitors. As with many systems changes, the conversion process is going to take time, but it is definitely coming. Film has been the traditional medium used to capture, store, and display imaging studies for about 80 years. The technology has evolved to a high level, and many imaging modalities are now digital and can be accessed by computers. As more and more radiology departments move to systems that are almost entirely digital, it is only a matter of time before film disappears as the viewing medium. (Huda & Szeverenyi 1999) Technical advances over the past few years have rapidly increased the possibilities for film-less radiology services provided by PACS. Such systems are also financially feasible for many healthcare practices, primarily because of the goals achieved through increased efficiency and improved patient care. In coming years, most medical facilities are likely to either convert or begin to convert to PACS as conventional film-based systems fade into the annals of medical history. Without the government blazing the trail, this technology certainly would not be where it is today. In recent years, improvements in the speed of computer processing, in networking technology, and in electronic storage devices have encouraged proliferation of film-less radiology departments in nongovernmental settings. References Blurne H, Kurniya K. (1987) Autoranging and normalization versus histogram analysis for automatic image processing of digital radiographs. Proc SPIE 1987; 767: 371-83 Bronson JG. (1998) Teleradiology reaches out. Imaging Econ 1998;11(5):62-6 Elam et al. (1992) Efficacy of digital radiography for the detection of pneumothoraces: Comparison with conventional chest radiography. AJR 1992; 158: 509-14. Foord K. (1999) PACS: the second time around. Eur J Radiol 1999; 32: 96-100. Huda W, Szeverenyi NM. (1999) The filmless radiology department: a primer. Appl Radiol 1999;28(2):30-4 Lai KW-S, Langlois S, Le P. (1999) A comparative study of a digital radiography system.Austral Radiol 1999; 43: 197-200. Langlois S, Le P, Vytialingam RC, Aziz NA. (1999) A time motion study of digital radiography at implementation. Austral Radiol 1999; 43: 201-5. Marchese B. (1998) Archiving: a piece of the PACS. Med Imaging 1998;13(3):43-8 Strickland NH. (1999) Can PACS make a radiology department more competitive Eur J Radiol 1999; 32: 113-15. Thaete et al. (1994) Digital radiography and conventional imaging of the chest: a comparison of observer performance. AJR 1994; 162: 575-81. Watkins J, Weatherburn G, Bryan S. (2000) The impact of a picture archiving and communication system (PACS) upon an intensive care unit. Eur J Radiol 2000; 34: 3-8. Watkins J. (1999) A hospital-wide picture archiving and communication system (PACS): the views of users and providers of the radiology service at Hammersmith Hospital. Eur J Radiol 1999; 32:106-12. Read More