Abstract: Devices that measure the electron density in a body by means of radiation scattered from a narrow pencil beam of penetrating radiation directed through the body, produce defective images on reconstruction of the density distribution because of multiple scattering of radiation. This can of course be reduced by scattered ray diaphragms, but cannot be eliminated entirely. The invention therefore provides a means for detecting the size of the multiple scattered radiation component be measurement. For this purpose, the detector array which measures radiation including the single scattered radiation, is screened, at least osscasionally, from the single scattered radiation and the detected intensity values measured by the detector elements when so screened, are used to correct the values generated by measuring the detected radiation including the single scattered radiation.

Abstract: In a device for determining the density distribution on a straight line by means of a narrow penetrating beam, the measuring accuracy for the center of an object to be examined is increased in that the primary beam is not only displaced perpendicularly to its direction, but is also rotated around a point in this center. To this end, a radiation source and a detector device are mounted on a supporting device which can rotate the path of the primary beam around a central point, preferably the center of the object, around an axis which intersects the path of the primary beam at right angles.

Abstract: A scintillator formed of a ZnWO.sub.4 single crystal having an absorption coefficient less than or equal to 1.8 cm.sup.-1 for the light having a wavelength of 520 nm is disclosed which has a luminescence wavelength of 480 nm and therefore can be combined with a photodiode, and which is high in radiation detection sensitivity, short in decay time, and specifically suitable for use in computed tomography.