End of an Era: The Demise of Film in Radiology
The following was written by David Avrin, MD, PhD, clinical member of the Interventional Radiology and Abdominal Imaging Sections at UCSF, Vice-Chair of Informatics, & Thomas Urbania, MD, Assistant Professor of Clinical Radiology at UCSF.
The days of comparing film screen radiology to computed or digital radiology are coming to an end. When originally introduced, computed and digital radiography suffered from deficient modulation transfer function compared with film-screen technology for small detail. Over the past two decades, that deficiency has essentially disappeared, and digital technologies have the added advantage of “window/level” contrast adjustments, magnification, and other more sophisticated image-processing tools at the workstation and preprocessor. Early digital radiology also suffered from the lack of high-resolution displays. Financial barriers such as the cost of detectors and displays were (and remain) relative obstacles to adoption. The cost of storage is no longer a significant financial issue. (Our department spends more annually on picture archiving and communication system [PACS] support employee salaries than on the capital acquisition of short- and long-term storage systems.)
Three important factors drove the transition from conventional to digital radiography:
- Although relatively low spatial resolution and fundamentally digital computed tomography and magnetic resonance were both the initial impetus and the “low-hanging fruit” for PACS development, it became clear that it is not practical to operate hybrid digital/conventional film departments.
- Despite comparisons of total operating costs favoring digital medical imaging, the security advantages of digital storage and the unique ability of digital images to be available “anytime, anywhere” across a health care enterprise, the widespread adoption of PACS was triggered by the broad deployment of multidetector computed tomography scanners that produced study image counts that became impossible to handle with film.
- Following Moore's Law – the observation that, over the history of computing hardware, the number of transistors on integrated circuits doubles approximately every two years – digital storage, detectors, and displays have and will continue to fall in price and increase in resolution, driven in part by the technologies developed for the consumer mass market in television and cameras. Film and chemical processing will become an antiquity.
As digital radiography completely replaces conventional radiographs, some may lament the “lost art” of handling and reading plain films, while others may celebrate the ease and advantages of the digital format. Nevertheless, the future is clear. For equivalent accuracy, workflow, access, and portability, it is inevitable that the era of film is over.