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Showing posts with label focal spot. Show all posts
Showing posts with label focal spot. Show all posts

Sunday, July 10, 2011

Anode Tubes

The combination of power (kW), anode angle and focal spot size dictate the use of stationary or rotating anodes. Mobile C-arm fluoroscopic applications are sufficiently handled by a stationary anode and 0.6mm focal spot. The use of 0.3mm focal spot mandates the use of a rotating anode.  

Focal Spot Fluoro

Focal spot size, measured in mm. directs image quality to a large extent. The smaller the focal spot, the better the image resolution. However, it is important to consider the image matrix of the system. For example, a 1k x 1k matrix with 0.3mm focal spot will produce approximately the same resolution as a 0.6mm focal spot at object-to-image distances of 40cm or less. Therefore, in C-arm imaging with 1k x 1k matrix, the performance of a 0.6mm is equal to a 0.3mm.