PACS and Unread Images1

In many circles, the justification for purchasing a picture archiving and communication system (PACS) has already been settled because of the proliferation of image data. A PACS is used to acquire medical images digitally from the various modalities, such as computed tomography (CT), magnetic resonance (MR) imaging, ultrasound, nuclear medicine, and digital radiography (1). The need to manage, transfer, and transport thousands of images effectively has led to medical and legal arguments for storing such data electronically rather than producing each image on film. Moreover, with the dissemination of imaging centers—as well as one’s referral base, which may extend beyond state or country boundaries—a PACS becomes an integral part of running an efficient department. The transfer of images to all-night reading stations for subsequent consolidation of emergency room coverage and the centralization of reading areas within a hospital or an enterprise-wide multisite radiology group, has also made life without PACS nearly impossible. Without the improvements in speed and bandwidth for the data transfer, however, these consolidations would be severely limited. Nonetheless, at a local level, one must still justify the huge investment in capital for a PACS to the financial planners of a hospital or outpatient group practice. We are facing an ever-challenging situation of dwindling budgets, increasing cost pressure, and growing demands to increase the efficiency and quality of related services (2). Typically, reductions in film cost and film library personnel are cited as a means of “financing” the PACS. PACS eliminates the film-associated workload, which includes processing, filing, and manual retrieval of previous studies from film storage. These steps constitute a considerable part of the total radiology turnaround time (3). The economics of PACS are characterized by higher fixed costs for the digital infrastructure and lower variable or marginal costs related to savings in film and personnel (1). Yet another source of savings in converting to a PACS is the greater capture of studies obtained within the department when film is not relied on as the primary means of viewing images. Heretofore, a common complaint in radiology departments was that clinicians would remove film images from the department before the radiologist could interpret them, rendering these examinations “nonbillable” without the cost of refilming. This is a common occurrence in most emergency room radiography departments, where images may be sequestered by the treating physician before being accessioned for billing or accounting. Not only do patients lose an opportunity for expert radiologic interpretation, but these lost films typically will not be available for future comparative studies (4). Accountability for them is particularly problematic without an integrated radiology information system (RIS). The number of lost studies will theoretically be reduced after integration of the RIS and PACS. When the radiology team and referring clinicians have simultaneous access to all patients’ digital data, patient care will improve. Therefore, in addition to decreasing the number of unread images, the use of PACS should help decrease the overall report turnaround time, permitting referring clinicians to make swift decisions on treatment options and health care delivery (4). At the Johns Hopkins Hospital, Baltimore, Md, the radiology department elected to implement the PACS in a piecemeal fashion because of funding considerations. For a time, the outpatient MR imaging service used a PACS and soft-copy reading to transfer and interpret images, while the inpatient MR imaging service continued to use hard-copy film reading. We were therefore able to compare the rates at which studies were lost with a PACS and remote reading (the outpatient service) and a film-based Acad Radiol 2002; 9:1326–1330