CPC G01T 1/1642 (2013.01) [A61B 6/5211 (2013.01); G01T 1/2985 (2013.01); G01T 1/362 (2013.01); G06T 11/005 (2013.01); G06T 2207/10104 (2013.01)] | 17 Claims |
1. A system comprising:
a positron emission tomography scanner comprising a plurality of crystals, the positron emission tomography scanner to perform a scan of an object and generate list mode data describing true coincidences and delay coincidences detected by the positron emission tomography scanner during the scan;
a processing unit to:
for each crystal, determine, from the list mode data, a number of delay coincidences which include the crystal for each of a plurality of time periods of the scan;
for each crystal, determine a singles rate associated with each time period based on the number of delay coincidences determined for all of the plurality of crystals for the time period;
for each time period, determine estimated mean randoms for each of a plurality of pairs of the crystals based on the singles rate associated with the time period for each crystal of the crystal pair, where estimated mean randoms determined for a pair of the crystals for a first time period are different from estimated mean randoms determined for the pair of the crystals for a second time period;
for each of the plurality of pairs of crystals, determine a composite estimated mean randoms based on the estimated mean randoms determined for the crystal pair for each time period; and
reconstruct an image of the object based on the composite estimated mean randoms for each of the plurality of pairs of crystals and the detected true coincidences; and
a bed to support the object and to move during the scan,
wherein a duration of each of the plurality of the time periods depends on a speed of bed movement during the scan.
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