Delay line clipping in a scintillation camera system

In a scintillation camera system having scintillator means for producing scintillations in response to impinging radiation, a plurality of amplifier drivers responsive to the scintillations for generating electrical pulses having amplitudes representative of radiation impinging on a respective portion of said scintillator means, and signal processing circuitry responsive to the electrical pulses for generating a plurality of data signals, said signal processing circuitry containing a plurality of coordinate signal amplifier driven lines for indicating coordinate information of the scintillation, and an energy signal amplifier driven line for indicating the energy magnitude of the scintillation, the combination including base line amplitude restorer means coupled to the energy signal and coordinate signal amplifier drivers, said base line amplitude restorer means comprising:

• a. a timing signal generator responsive to at least one of the energy and coordinate signal amplifier driven lines to produce a timing signal in response to the occurrence of a radiation scintillation;
• and
• b. gating means coupling at least one of said coordinate signal lines to a reference potential in response to said timing signal for conditioning the signal processing circuitry for operation in anticipation of receipt of data representing a scintillation.

A radiation camera system comprising a radiation detector, a plurality of amplifier driven coordinate channel lines coupled to the detector for indicating the locus of a radiation event, an amplifier driven energy channel line for indicating the energy magnitude of the radiation event, delay line clipping means having a delay line coupling the output of the amplifier of said energy channel line to a reference potential, first differential amplifier means coupled to said delay line for providing a single delay line clipped voltage indicative of the magnitude of the respective radiation event;

• and a current sensing converter means coupled to a common of said delay line for sensing the current therein and cooperating with the delay line for generating double delay line clipped output pulses time synchronized with the single delay line clipped pulses and being indicative of the occurrence of a radiation event.

A method of operating a radiation camera system having a detector for producing radiation signals in response to impinging radiation, a plurality of amplifier drivers responsive to the radiation signals for generating electrical pulses having amplitudes representative of radiation impinging on a restrictive portion of said detector, and signal processing circuitry responsive to the electrical pulses for generating a plurality of data signals, said processing circuitry including a plurality of coordinate signal amplifier driven lines for indicating coordinate information of the radiation and an energy signal amplifier driven line for indicating the energy magnitude of the radiation, and a base line amplitude restorer coupled to the energy signal and coordinate signal amplifier drivers, said method comprising the steps of:

• a. producing a timing signal in response to the occurrence of a radiation event as sensed by signals transmitted by at least one of the energy and coordinate signal amplifier driven lines, and
• b. gating at least one of the coordinate signal lines to couple said coordiate signal line to a reference potential in response to said timing signal for conditioning the signal processing circuitry for operation in anticipation of receipt of data representing a radiation event.

In a radiation camera system having radiation sensitive structure for producing radiation indicating signals in response to radiation impinging on the radiation sensitive structure, and circuitry responsive to the radiation indicating signals for generating sequences of data signals representative of radiation impinging on the radiation sensitive structure, signal processing circuitry including pulse shaping circuitry responsive to the data signals for generating a plurality of data pulses defining the situs of respective radiations and a display apparatus for producing images representing the radiation impinging on the radiation sensitive structure, the improvement wherein the pulse-shaping circuitry comprises a compensating circuit including circuitry coupled to produce and combine first signals representing data signals and second signals representing data for decreasing base line fluctuations of the data pulses and thereby improving pulse detection.