Scintillation data collecting apparatus and method

A scintillation data collecting method for a scintillation camera and data processing means, said camera including a crystal in which scintillations are produced at spatial locations with given intensities as a result of radiation stimuli, and a plurality of light intensity measurement devices located over a surface of said crystal for respectively collecting light from said scintillations and generating intensity signals having given amplitudes indicative of said intensities, said method comprising steps of:

• adding said intensity signals;
• carrying out a predetermined validity analysis on the sum of said intensity signals for detecting and determining whether said scintillations are noise or valid scintillations;
• comparing individually the amplitudes of said intensity signals to a threshold value and generating thereby corresponding resulting comparison signals;
• and
• converting by means of converters signals derived respectively from the intensity signals depending on the corresponding comparison signals into corresponding digital value signals so that said digital values are generated in relationship with said valid scintillations;
• whereby said digital value signals of said valid scintillations can be computed by said data processing means to determine the spatial locations of said valid scintillations.

A scintillation data collecting apparatus to be used with a scintillation camera and data processing means, said camera including a crystal in which scintillations are produced at spatial locations with given intensities as a result of radiation stimuli, and a plurality of light intensity measurement devices located over a surface of said crystal for respectively collecting light from said scintillations and generating intensity signals having given amplitudes indicative of said intensities, said scintillation data collecting apparatus comprising:

• an adder for adding said intensity signals and thereby producing a sum signal, and analyzing means for carrying out a predetermined validity analysis on said sum signal and generating a resulting validity signal, said adder and said analyzing means forming a scintillation detecting means for detecting said scintillations and determining whether said scintillations are noise or valid scintillations;
• a plurality of conversion units connected respectively to said light intensity measurement devices for individually converting said intensity signals into digital value signals, each of said conversion units comprising a serial analog-to-digital converter whose output gives a most-significant bit first and a least-significant bit last and means for triggering said serial converter when said validity signal indicates that a valid scintillation has occured;
• most significant bit detector means for detecting which conversion unit is first to produce a positive bit when the validity signal indicates that a scintillation has occurred to determine which conversion unit has a large digital value signal resulting from the valid scintillation;
• and
• reset means for controlling a reset operation of some of said analog-to-digital converters which are determined to be uninvolved in receiving signal originating from light from said scintillation based on a result from the most-significant bit detector means, and for determining which of said analog-to-digital converters have said digital value signals which are to be sent to said data processing means;
• whereby once a first positive bit of said analog-to-digital converters is detected and the involved converters are determined, the reset means can determine which converters have useful data and reset said uninvolved converters so that they are free to convert a future intensity signal of another valid scintillation even while said converters which are involved are still converting and producing their lesser-significant bits.

A scintillation data collecting method for a scintillation camera and data processing means, said camera including a crystal in which scintillations are produced at spatial locations with given intensities as a result of radiation stimuli, and a plurality of light intensity measurement devices located over a surface of said crystal for respectively collecting light from said scintillations and generating intensity signals having given amplitudes indicative of said intensities, said method comprising steps

• adding said intensity signals;
• carrying out a predetermined validity analysis on the sum of said intensity signals for detecting and determining whether said scintillations are noise or valid scintillations;
• triggering conversion of serial analog-to-digital converters which are each connected to a corresponding one of said intensity signals when a valid scintillation is detected, said converters producing a digital value signal starting with a most-significant bit and ending with a least-significant bit;
• detecting a first produced positive bit of said converters and determining which converters are involved in receiving signal resulting from said valid scintillation;
• resetting some of said converters which are uninvolved in receiving signal from said valid scintillation;
• and
• transferring said digital value signals from said converters which are involved when conversion is complete;
• whereby it is determined which converters have useful data and said uninvolved converters are free to convert intensity signals from a future valid scintillation even while said converters which are involved are still converting and producing their lesser-significant bits.