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Biomedical subjects

B S Baxter

Publications and source records attributed to B S Baxter.

4 recordsLinked to original sources

A distribution system for digital images from diverse image sources. Incorporating a local area network in an imaging environment.

This paper proposes a unified image-processing and viewing system as a viewing station and initially as the central file server in a unified digital image distribution and processing network, linking various digital image sources through a high speed data link and a common image format. The network allows for viewing and processing of all images produced within the complex and for locating viewing stations in any number of convenient areas. The system proposed can be slowly expanded to include all the digital images produced within the department of institution.

Computers

Factors affecting the measurement of size and CT number in computed tomography.

Computed tomography scanners may be used to make anatomic size measurement; however, manipulating the viewer controls (especially the window center) can have a significant influence on the apparent size of structures in the image. A special phantom was constructed to study the effect of window center adjustments on the apparent size of lone cylindrical objects (no variation within slice thickness) and also for spherical objects (maximum variation within slice thickness). Using this phantom, the authors were able to identify several commonly encountered situations in which both the apparent size and CT numbers may be seriously in error. It was found that for cylindrical objects larger than about one transverse resolution element and aligned with the scanner axis, CT numbers may be determined accurately; however, the apparent diameter changes by several millimeters as the window center setting is changed. CT numbers for spheres are inaccurate when the diameter is comparable to or less than the slice thickness and, as a result, diameters of spheres cannot be measured accurately with fixed window center settings. Diameters of spheres can be measured accurately (+/- 1 mm) if the sphere is centered in the slice and the full width at half maximum of the CT number profile is used.

Humans