ABSTRACT
Positron emission tomography (PET) is the leading tool in nuclear cardiology for noninvasive assessment of molecular function. Computed tomography attenuation correction (CTAC) is an integral component required for accurate PET-CT imaging. PET is built on the technique of coincidence photon detection. To detect many annihilation photons, a PET scanner is typically constructed of multiple circular rings of scintillation crystal detector blocks stacked together, allowing line of response (LOR) projections through the subject to be obtained simultaneously at all angles around the object. A coincidence event indicates that an annihilation occurred somewhere along the line between two PET detectors, implying that the radioactive atom that decayed should be located along that same LOR. Data acquisition commences with positioning of the patient on the scanner bed and determining the axial range for imaging. Modern clinical scanners employ multirow detectors enabling to reconstruct multiple slices from a single bed position.
