February 2004 Bulletin

A primer on filmless radiology

Know the pros and cons to before making the transition

By A. Herbert Alexander, MD

Many hospitals have already moved to filmless radiology (FR). Instead of viewing a radiographic image on conventional X-ray film, physicians can view plain films, CAT scans and MRIs on computer screens. The price tag on FR has now dropped to a point where some orthopaedic surgeons have embraced and incorporated this new technology into their private practices.

Before I made the transition, I spent countless hours learning about filmless technology. Should you decide to make this transition, here are some of the concepts that will be important: the difference between computed radiography (CR) and digital or direct radiography (DR); the components required for FR; and the why and why not of making the conversion including the economics of FR.

Understanding the difference
First, you’ll need to understand the basic conceptual difference between film and filmless. With film, a static image is displayed on the radiograph.
With filmless, a collection of data is displayed on a monitor. Also, the digital X-ray image can be manipulated, duplicated, displayed, transmitted and saved within seconds.

A low quality film image must be taken again, whereas as a digital image can be manipulated with software so that the contrast and brightness is satisfactory for interpretation without taking another exposure.

Two kinds of filmless X-ray systems
There are two kinds of filmless X-ray systems. In digital or direct radiography (DR), the X-ray image is exposed on an electronic apparatus and the X-ray beam is converted directly to an image without the use of a cassette. This is similar to the concept used in radiographic C-arms.

In computed radiography (CR), special cassettes are used that contain X-ray sensitive image plates. After exposure, these plates are read by a CR reader. The CR reader converts the image on the exposed plate to a digital image. The advantage of CR is that the cassettes also can be used with conventional X-ray equipment. This means that all the X-ray machines present in hospitals and doctors’ offices now can still be used as the X-ray source. The CR cassettes are the same size as conventional film cassettes.

With DR, all new equipment is required because the receiving end for converting X-ray transmission to digital images is part of the DR hardware. These machines are much more expensive at this point in time and beyond the economic reach of most small orthopaedic practices. Consequently, most offices and hospitals with a significant investment in conventional X-ray equipment will turn to CR instead of DR.

FR components

However, the most important component of FR is the software you interact with to manipulate and view your images. This software is referred to as “Picture Archiving and Communications Systems” or PACS. PACS software is what will make you, as the user, a devout believer (or disbeliever) in this technology. Unfortunately, not all PACS are the same. Typically, high-end expensive PACS designed by and for radiologists and hospitals are woefully inadequate for an orthopaedic surgeon. Find a good PACS, designed by and for orthopaedic surgeons, and you will be very pleased.

l Hardware and software for image archiving: One must also have a method for storing and retrieving digital images. The hardware consists of a computer server that stores the images for immediate retrieval, some kind of permanent storage such as tape backup or DVDs and the software that manages the image archiving.

In my office, our PACS system takes care of the archiving automatically and I do not need separate software. The permanent storage is a DVD jukebox that holds 200 DVDs. I calculated that my office could store 67 years’ worth of digital images on 200 DVDs.

Benefits of converting
One can run the numbers and find that ultimately FR will be less expensive in the long run. Certainly, there is a significant expense in the beginning. Yet, the savings of not having a darkroom, space for film storage, expense for film jackets, labels, chemicals and film offsets this expense.

FR is a time saver. Processing a digital image on a CR reader takes 30 to 60 seconds compared to two minutes on a conventional film processor (not to mention the time it takes to hand-carry the film).

I can manipulate the digital images using magnification, brightness and contrast. My PACS also has built-in tools that measure angles, Cobb angles, and distances as well as templates for prostheses. I never lose a digital X-ray and digital images can be viewed by almost an unlimited number of individuals from different locations simultaneously. My digital X-rays can be transferred to the hospital, and their digital images (including MRIs) can be transferred to my office in seconds. Finally, I can see my digital X-rays from any location that has a computer with an Internet connection, including my home.

Why not make the conversion?
Computer phobia may prevent some from even considering this technology. Initial expense may be considerable and if one is not planning to be in practice for several years, it may not be worth the trouble to convert. If you relish looking for lost films, FR is not for you.

Finally, one must consider the obstacle of converting from films to filmless. What does one do with all the old films?

Some practices digitize the old films using film scanners. Others maintain a physical storage of old films until it is legal to destroy them.
However, FR is here to stay. Its utility is proven. It is also spreading to more and more hospitals and practices. FR is an integral part of the totally electronic office (TEO). I highly recommend FR to all orthopaedic surgeons.

If you are just opening a new office or are a graduating resident, my advice is to move directly to FR, electronic medical records and computed practice manager. Computed radiography and the TEO have increased my efficiency, quality of care and patient satisfaction.

A. Herbert Alexander, MD, is president of Alexander Orthopaedics and chief of staff at St. Luke’s Wood River Medical Center in Ketchum, Idaho. He is also the associate editor-in-chief of The American Journal of Orthopedics and chairman of the AAOS Internet Communications Committee. He can be reached at (208) 727-0005 or via e-mail at herb_alexander@msn.com.

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