The digital imaging workstation. 1990

Abstract

Picture archiving and communication systems (PACS) are expected to convert film-based radiology into a computer-based digital environment, with associated cost savings and improved physician communication. The digital workstation will be used by physicians to display these “soft-copy” images; however, difficult technical challenges must be met for the workstation to compete successfully with the familiar viewbox. Issues relating to image perception and the impact on physicians’ practice must be carefully considered. The spatial and contrast resolutions required vary according to imaging modality, type of procedure, and class of user. Rule-based software allows simple physician interaction and speeds image display. A consensus appears to be emerging concerning the requirements for the PACS workstation. Standards such as the American College of Radiology/National Electrical Manufacturers’ Association Digital Imaging and Communication Standard are facilitating commercial applications. Yet much careful study is needed before PACS workstations will be fully integrated into radiology departments.

Figure 1

Illustration of the transformation from the original 14 × 17-inch chest radiograph to the image displayed on the CRT for two cases: (a) scan lines horizontal and (b) scan lines vertical. The numbers apply to a particular set of hardware described in the text.

Figure 2

Image memory management in a workstation. The same 16-MByte image memory can be configured in various ways depending on the application. If the intent is to show two high-resolution chest images at their acquired 2,048 × 2,048 resolution, then the images would be loaded as shown in a. However, if the workstation was being used for a less demanding application, the same 16-MByte image memory could be configured to hold eight 1,024 × 1,024 images, as shown in b. Finally, if the workstation was being used to show digital images from, for example, an MR imager, the same 16 MBytes could store almost two complete examinations. Note that we have assumed a 16-bit-deep image memory. If images were, in fact, 8 bits deep, twice as many images could be stored in the same space.