Abstract: A detector slit for .theta. rotation in an X-ray examination apparatus utilizing the Seemann-Bohlin focusing principle is suspended on a mechanical arm which is capable of rotating about a shaft through the center of the focusing circle. The Seemann-Bohlin system is for .psi. adjustment tiltable about an axis through an irradiated area on an object to be examined. The readjustment of the detector during the .theta. rotation is controlled by a device which provides detector rotation with with a 1:2 gear wheel transmission. For automatic limitation of a .theta. path to be chosen, the detector housing comprises an abutment pin which cooperates with switching elements connected to the mechanical arm. The X-ray tube has a construction reduced length and is connected to a high-voltage source via a rotatable right-angled connector.

Abstract: A positron emission tomography camera having a patient area with a plurality of fixed detector rings positioned side-by-side around the patient area to detect radiation. Each ring includes multiple layers of scintillation detectors in which the detectors in one of the layers is offset relative to the detectors in the other layers. The thickness of each layer increases exponentially from the inside of the ring to the outside of the ring. Identification of the scintillation detector may be performed by using layers with different timing constants, using silicon avalanche photodiodes or using a light guide transferring the light received from the staggered detectors to a non-staggered rectangular matrix.

Abstract: The device operates by means of the X-ray fluorescence principle wherein a beam of primary X-rays is directed on to a coated test specimen and X-rays emitted back by the test specimen are counted to determine the thickness of the coating. The device has a stage for supporting test specimens, an X-ray generator, a collimator device for the primary X-rays, a counter for X-rays emitted back by the test specimens, and a displacement device for moving the stage in at least one direction at right angles to the collimator device, and in the direction of the X-ray beam. A rod composed principally of aluminum of a material of low atomic number is positioned at a safe distance beneath the collimator device, and approximately at right angles to the X-ray beam. The shaft of an electric motor imparts periodic motion to the rod. An evaluating device monitors the motion of the rod and outputs a signal when the rod is momentarily stopped.

Abstract: Disclosed is a test phantom for evaluating a computed tomographic scan of nodules in a lung of a human or non-human animal comprising a device which simulates a 15 to 40 mm thick transverse section of said animal the tissue simulating portions of said device are constructed of materials having radiographic densities substantially identical to those of the corresponding tissue in said simulated transverse section of said animal and contain voids therein which simulate, in size and shape, the lung cavities in said transverse section. At least one of the voids has positioned therein a test reference device constructed of a material of predetermined radiographic density which simulates a lung nodule.