[en] The proposed device is aimed at the impovement of the accuracy of the results obtained in spiral scanning of radioactive objects in the case of strong background radiation and noises. This aim is attained by that the measuring collimated converter, whose sensitive surface is as large as the region being scanned, remains fixed, whereas the movable collimator provides coding of useful data due to a predetermined arrangement of collimator channels and its spiral movement. The object being scanned is within the collimator. Immobility of the measuring converter, which may be a scintillation detector with a large-surface organic or inorganic scintillator, provides stable operation of the device under the conditions of changing magnetic fields and background radiation. Due to coding of measured data by the collimator, the error attributed to fluctuations of background and noise pulses is considerably reduced