Abstract: In a method for correcting a calibration table T(n,k) of a CT apparatus that contains calibration values, the CT apparatus having a detector system with N≧2 rows of detector elements following one another in the z-direction that include a first active row of detector elements in the z-direction and a last active row of detector elements in the z-direction, for correcting the calibration values of the aforementioned first and last active rows of detector elements, a reference vector R(k) is produced, the error is determined with respect to the first and last active rows of detector elements, and the error F(n,k) of the first and last active rows of detector elements is subtracted from the corresponding calibration values of the calibration table T(n,k) for determining corrected calibration values Tcor(n,k) with respect to the first and last active rows of detector elements.

Abstract: A stereographic tomogram observing apparatus comprises a memory for storing tomographic picture data of a specific part of internal tissue of the object, a reading device for reading out the tomographic picture data, a projecting type CRT for projecting light beams at intensities corresponding to tomographic picture data read out by the reading device, a picture reproducing device made up of a plurality of tomographic picture reproducing screens arranged in parallel and for reproducing corresponding tomographic pictures, and a switching circuit for making the tomographic picture data read out correspond to the screen for reproducing the tomographic picture data.

Abstract: A tomodensitometric apparatus for the radiological examination of an object by relative rotation with respect to said object of a fixed array consisting of a source of penetrating radiation and a plurality of detectors disposed along a line. In order to correctly position the object in the center of the radiation field prior to the examination and without subjecting the object to a dose of test radiation, the invention provides a movable screen which is placed between the source and the object to be examined. The dimensions of the screen are such as to prevent the radiation emanating from the source from reaching any but at least one of the two outermost-lying detectors in the line of detectors.