Abstract: A CT scanner (10) non-invasively examines a region of interest of a patient to create an image representation that is stored in an image memory (14). Each pixel of the image representation has a relatively large number of bits of radiation intensity resolution, e.g. 14 bits or 16k levels, which is larger than the gray scale resolution of a conventional video monitor (24), e.g. 8 bits or 256 levels. A look-up table (38) digitally filters each pixel value with digital filter values to reduce the number of levels of each pixel value to the number of gray scale levels displayable by the video monitor. While the image is being displayed, the operator selectively adjusts the digital filtering to optimize the displayed image for the intended diagnostic purpose. During the vertical flyback or other non-display periods of the video monitor, a central processor (30) generates most significant bits of addresses that read digital filter longwords from a filter memory (44).

Abstract: A gantry (A) of a CT scanner system has an x-ray tube (10) and radiation detectors (14) which produce patient diagnostic data. An operator using a keyboard (20) or other manual controls operates the x-ray tube and other components of the gantry. The operator also causes a central processing unit (C) to process the diagnostic data with a selected algorithm to provide diagnostic information for display on a display (24). The same keyboard and displays are also utilized in routine service and repair processes. A system monitor (E) compares operating conditions sensed by sensors (50), such as operating temperatures and compares them with acceptable operating conditions. When the sensed conditions are unacceptable, a timer (60) is started and shuts down (68) gantry operation after a preselected duration. The operator can override (72) the timed shut down, but each such override is recorded (74) in permanent storage (32).

Abstract: A first electromechanical transducer (40) generates a first electrical signal indicative of rotation of a ball (A) relative to a first axis. A second electromechanical transducer (50) generates a second electrical signal indicative of rotation of the ball relative to a second axis. A third electromechanical transducer (60) generates a third electrical signal indicative of rotation of an annular ring (12) around the periphery of the ball, i.e. a third axis. A resolver circuit (D) converts the first, second, and third electrical signals into an indication of movement or position along the first, second, and third axes.

Abstract: A system and method for monitoring progress of a radiographic exposure is disclosed. The system samples the cumulative radiation as an exposure progresses, and aborts the exposure if the rate of rise in cumulative radiation is insufficiently low to cause a good exposure. Similarly, the system will terminate an exposure early, at a properly timed out interval, even if the radiation accumulation rises excessively fast due to an erroneous system set up.