Abstract: A method and apparatus to calibrate and correct magnetic and geometrical distortions in an imaging system, specifically a computed tomography (CT) system, includes a distortion measuring object which is placed on the surface of an image intensifier. An image frame of the distortion measuring object is generated, and a correction table is generated to correct the image frame. Once the correction table has been generated using the distortion measuring object, subsequent image frames are corrected using the correction values in the correction tables. A method and apparatus to calibrate and correct offsets, veiling glare and scatter in an imaging system, specifically a computed tomography system. An image frame is generated and areas not directly impinged by direct radiation are used to correct areas of the detector that are directly impinged. A method and apparatus for correcting and calibrating an imaging system, specifically a computed tomography system.

Abstract: An ultrasound high velocity flow measurement apparatus uses cross-correlation between consecutive echoes of coded pulses which are matched filtered at the receiver to determine velocity profiles of flowing blood. Because coded pulses are used, the interval between two pulses can be made arbitrarily small, effectively removing the peak velocity limitation.