US 7,321,122 B2
System for selecting true coincidence events in positron emission tomography
Douglas Bryman, Vancouver (Canada)
Assigned to Triumf, B.C. (Canada)
Filed on Dec. 01, 2005, as Appl. No. 11/290,448.
Claims priority of provisional application 60/631881, filed on Dec. 01, 2004.
Prior Publication US 2006/0138332 A1, Jun. 29, 2006
Int. Cl. G01T 1/164 (2006.01); G01T 1/166 (2006.01)
U.S. Cl. 250—363.03  [250/363.04] 5 Claims
OG exemplary drawing
 
1. A method of collecting coincidence data relating to positron annihilation events in which two back-to-back photons are emitted comprising:
selecting coincident events detected within a Compton camera array in which a first γ-ray and a second γ-ray each surpass an energy threshold and in which the first γ-ray is Compton scattered and is detected in a first detector and the second γ-ray is Compton scattered or photo-absorbed and detected in a second detector, the first and second detectors being arranged in an opposed configuration;
reconstructing a cone surface corresponding to possible incident angles for at least one of the first or second γ-ray on at least one of the detectors;
projecting the reconstructed cone onto the opposed detector;
determining, within an angular resolution and a position resolution of the Compton camera array, a probability corresponding to an overlap of the reconstructed cone surface with a location of the first or second γ-ray detected in the opposed detector;
retaining data corresponding to coincidence events having a probability above an acceptance threshold; and
using the retained data for constructing an image.