US 12,169,260 B2
Mean randoms estimation from list mode data
Vladimir Panin, Knoxville, TN (US); and Mehmet Aykac, Knoxville, TN (US)
Assigned to Siemens Medical Solutions USA, Inc., Malvern, PA (US)
Filed by Siemens Medical Solutions USA, Inc., Malvern, PA (US)
Filed on Apr. 30, 2021, as Appl. No. 17/302,347.
Prior Publication US 2022/0350037 A1, Nov. 3, 2022
Int. Cl. G01T 1/164 (2006.01); A61B 6/00 (2024.01); G01T 1/29 (2006.01); G01T 1/36 (2006.01); G06T 11/00 (2006.01)
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
OG exemplary drawing
 
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.