Image Data Transfer Research Articles

Telephone line transfer using a local filing system in Hokkaido

An image-data transfer system using a public telephone line has been constructed between Hokkaido University Hospital (HUH) and Nakashibetsu Town Hospital (NTH). The latter is situated about 420 km from Sapporo and does not have full-time radiologists. A local filing system coupled with a film reader and an optical disk had been installed in HUH in 1986, and in NTH in 1988. Both systems were connected by a public telephone line along which the transfer speed is 9600 bps. Images originating at NTH, mostly CT, were digitized by the film reader and sent to HUH after compression at a ratio of about 5:1 to 10:1. Clinical information concerning a patient was also sent to HUH using facsimile. Radiologists interpreted the transferred data (12 CT images on a film) on the CRT and sent back a written report to NTH using facsimile. The system and its image quality are largely acceptable, especially in an emergency case for brain and abdomen, although the transfer of a film takes about 7 to 20 min.

Design and operation of a nuclear medicine picture archiving and communication system

Construction of a new Veterans Administration Medical Center provided a unique opportunity to design and implement a state-of-the-art nuclear medicine department in a large teaching and research hospital. The new medical center allowed the acquisition of all new gamma cameras and computer systems without any historical need to patch together a system of old and new equipment. The picture archiving and communication system (PACS) was designed to link five gamma cameras to four image viewing areas, followed by digital archive on an optical disc. The gamma cameras' computers and viewing areas' computers are linked to a central networking computer in a manner that provides nine independent but digitally communicating image computers. Each nuclear medicine computer is capable of acquiring gamma camera data while possibly also performing up to three other simultaneous tasks: analysis of image data, transfer of image data from node to node, and patient database manipulation. The nine image computers each appear to the user as a digital file cabinet, containing various folders, which in turn contain patient studies. To transfer a patient study from one location to another, the user simply queues a transfer request by selecting a file drawer-folder combination for the source and destination locations. It takes only a few seconds to queue a transfer request, and the transfer is complete about a minute later without any further user intervention. A computer genie awakens during the early morning off-hours and performs housekeeping tasks, including movement of patient studies (based on date of acquisition) from active viewing folders to inactive archive folders. All scheduling, workload data, patient image reports, etc, are handled by a patient textual information database system. Patient reports and scheduling information are transmitted to the medical center's central computer where they are made readily available throughout the medical center. The PACS, in clinical use since the spring of 1988, is practical and well-received by technologists, nuclear medicine physicians, and more importantly, our consumer, the referring physicians.

Transfer and combination of digital image data.

Digital images are produced by many medical imaging modalities. In general, imaging techniques have tended to compare rather than combine image information. Video and photographic methods have, however, been used to transfer image features from one modality to another (Higa et al, 1983; Morin & Sirr, 1984) and it has become practicable to transfer digital image data between devices. Hence it is now feasible to investigate the digital combination of images which display data in the same plane of interest. This should be particularly worthwhile if one modality provides complementary information, either by providing features which the other modality lacks or by confirming image features derived from a different physiological measurement. Transmission computed tomography (CT) and emission computed tomography (ECT) images are particularly suited for combination as the former provides anatomical detail whilst the latter provides functional information. The good edge features of the CT images should allow the correlation of images and improve the quantitation of the ECT studies. This paper describes the methods used and the problems found both in transferring digital image data between systems and in presenting the combined information on a single image data processor.