Film Digitizers
Kodak LS-75
The best film digitizer you can purchase on the market is the Kodak LS-75 laser film digitizer. While slightly more expensive than CCD digitizer from rivals such as Vidar and Howtek, the Kodak LS-75 has significantly better image quality and much better image contrast. While other digitizers have the same or similar resolution, the number of pixels in the images is not the most important factor for diagnostic interpretation. All the digitizers on the market have plenty of resolution. What is most important is image contrast, and the ability of the digitizer to detect subtle gray scale transitions in the diagnostic film.
A very simple but important way to compare a Kodak LS-75 digitizer to a Vidar or Howtek digitizer is to place a piece of clear scotch tape on a dark area of the xray film, then digitize the film. With the Kodak LS-75 you can easily detect the clear tape. With the Vidar or Howtek you cannot see the tape.
Why is this? Because the LS-75 uses a high powered helium neon laser to penetrate the dark areas of the fillm, and an extremely sensitive photomultiplier tube to detect the light passing through the film. Both the Vidar and Howtek scanners use light emitting diodes (LED) and charged couple devices (CCD) to detect the image. The LED's are similar to the ones used in watch displays and your microwave, while the CCD technology is similar to the ones used in a home video camcorder. The LED/CCD technology works fine in less dense areas of the film, but only a laser/PMT combination can penetrate dark areas of the film, and more importantly, detect subtle grayscale changes in the dark areas of a film.
So if you are comparing digitizers, where you really want to pay attention is the very subtle grayscale changes in the dark or nearly black portions of the xray film. This is where the Kodak LS-75 FAR outperforms the other two systems, and provides much better diagnostic quality images.
Kodak LS-75 Film Digitizer Brochure
Laser vs CCD Technical White Paper
Kodak LS-75 Software User Reference Manual
Kodak LS-75 Software Administrator Manual
Digitizer Maintenance
InTelemed is one of the leading digitizer maintenance companies in the world. We stock a complete line of spare parts for the LS-75 and have the tools and equipment to perform everything from periodic preventitive maintenance to a complete system rebuild and refurbishment. According to Kodak, the LS-75 (and any digitizer for that matter) should be calibrated twice per year for normal usage. If you are a film-free facility and are using the LS-75 primarily for comparison studies, you can extend that preventative maintenace schedule to once per year.