University of Iowa Hospitals and Clinics: Department of Radiology: Teleradiology

Components

1. An image sending station

2. A transmission network

3. A receiving/image review station.

These components are interconnected as shown below.

NOTE: At the present time, all teleradiology components must be purchased from the same vendor to be compatible.
Patient images are electronically encoded in a digital format at the sending station, sent on the transmission network and received, viewed, and possibly stored at the review station. The elements comprising each of these three major components are:

Image Sending Station

1. image (film) digitizer

2. network interface device (most commonly a phone modem)

There are three general categories of film digitizers

1. TV camera digitizers, ("low-end" products)

2. Charged Coupled Device (CCD) scanner digitizers ("middle of the line" products)

3. Laser scanner digitizers ("top-of-the-line" products)

All three film digitizers perform the same basic function: the equipment operator inputs the x-ray film to the scanner which converts the analog image of the film to digital information. The main differences among digitizers are quality of image resolu tion, ease of use, and cost.

Once the film digitizer has converted the image to a digital format, the data is sent to the modem upon command of the equipment operator. The modem is the control device which converts digital data into electrical impulses that are sent along the tran smission network.

Image Sending Station

Transmission Network
The transmission network can be wire, fiber optics, or microwave. The most commonly used transmission networks currently in use for teleradiology are those provided by the telephone companies. This network utilizes both wire and fiber optics. Transmiss ion speed (and cost) are closely related to the transmission mode.

Receiving/Image Review Station
A receive/image review station consists of:

1. network interface (modem)

2. personal computer with storage medium (e.g. hard disk drive)

3. one or two TV monitors

4. optional hard copy device printer

Transmission Network
The modem on the review station receives the electrical impulses from the transmission network and converts them back to digital image data. These data are then sent via the modem to the computer disk for storage. Once the image data are stored, the ra diologist at the station can access the image via the computer and display it on the TV monitor. The radiologist then performs software manipulation functions to "enhance" the image. Software functions vary, but almost all have the capability of window/l evel and magnification.

If a printer is attached to the receiving station, hard copy images can be printed. Two types of hard copy imagers are normally used; a multiformat camera or a laser printer.

Next Page | Previous Page | Section Top | Title Page