[Development of DICOM image viewing software for efficient image reading and evaluation of distributed server system for diagnostic environment].

To construct an efficient diagnostic environment using computer displays, the author investigated the time of network transmission using clinical images. In our hospital, we introduced optical-fiber 100Base-Fx Ethernet connections between 22 HIS-segments and one RIS-segment. Although Ethernet architecture is inexpensive, the speed of image transmission becomes 2371 KB/sec. (4.6 CT-slice/sec.) in the RIS-segment and 996 KB/sec. (1.9 CT-slice/sec.) from the RIS-segment to HIS-segments. Because one examination is transmitted in one minute, it does not disturb image reading. Otherwise, a distributed server system using inexpensive personal computers helps in constructing an efficient system. This investigation showed that commercially based Digital Imaging and Communications in Medicine(DICOM) servers and RSNA Central Test Node servers are not so different in transmission speed. The author programmed and developed DICOM transmission and viewing software for Macintosh computers. This viewer includes two inventions, dynamic tiling window system (DTWS) and window binding mode(WBM). On DTWS, windows, tiles, and images are independent objects, which are movable and resizable. The tile-matrix is changeable by mouse dragging, which realizes suitable tile rectangles for wide-low or narrow-high images. The arranging window tool prevents windows from scattering. Using WBM, any operation affects each window similarly. This means that the relationship of compared images is always equivalent. DTWS and WBM contribute greatly to a filmless diagnostic environment.