Multiplexing, a technique used extensively in telecommunications, could boost data collection rates in CT scanners by a factor of hundreds, leading to better images, and potentially lower X-ray exposure for patients, says a research team from the University of North Carolina, Chapel Hill.
Modern CT scanners serially collect over 1,000 images in about one second by rotating an X-ray tube at high speed around an object of inter est. A multiplexing CT scanner, in contrast, uses several X-ray sources to simultaneously capture images from multiple views. In general, the multiplexing technique raises collection speed by a factor of N/2 (N=total number of images). For example, a clinical CT scanner that acquires 1,000 views per gantry rotation would see a 500-fold rise in collection speed.
The team recently built a 25-pixel multiplexing CT scanner, though engineering challenges remain to reach the ultimate goal: a 1,000-X-ray pixel scanner. The group says multiplexing scanners would not cost significantly more than serial units because emerging fabrication technology can put hundreds of X-ray cathodes on a single silicon wafer.