Scanning means including a screen which blocks radiation according to the probability of its origin

Claim 1

IN A RADIOACTIVITY SCANNING SYSTEM FOR SCANNING A FIELD OF RADIOACTIVITY INCLUDING RADIOACTIVITY DETECTOR MEANS FOR RECEIVING RADIOACTIVITY FROM SAID FIELD AND DEVELOPING OUTPUT SIGNALS IN ACCORDANCE THEREWITH AND READOUT IMAGE PRODUCING MEANS FOR DEVELOPING READOUT IMAGE PRODUCING SIGNAL PULSES IN RESPONSE TO SAID OUTPUT SIGNALS FOR RECORDING A READOUT IMAGE ON RECORDING MEANS IN ACCORDANCE WITH THE INTENSITY LEVELS OF SAID RADIOACTIVE FIELD, THE IMPROVEMENT WHICH COMPRISES SCREENING MEANS INTERPOSED BETWEEN SAID IMAGE PRODUCING MEANS AND SAID RECORDING MEANS, SAID SCREENING MEANS EXHIBITING A PREDETERMINED PATTERN OF READOUT IMAGE PRODUCING SIGNAL PULSE PASSING AND BLOCKING CHARACTERISTICS ACCORDING TO A STATISTICAL PROBABILITY AS TO THE LOCATION OF THE ORIGINATION OF DETECTED RADIOACTIVITY RELATIVE TO THE LOCATION OF SAID DETECTOR MEANS, WHEREBY FOR EACH IMAGE PRODUCING SIGNAL PULSE AN IMAGE PATTERN IS RECORDED ON SAID RECORDING MEANS IN ACCORDANCE WITH SAID PREDETERMINED PATTERN.