Positron Emission Tomography
Positron Emission Tomography
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DOI：
10.1002/9781118754467.ch1
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发表时间：
2019-07
期刊：
影响因子：
--
通讯作者：
J. J. Vaquero-J.;S. Bacharach
中科院分区：
文献类型：
--
作者：
J. J. Vaquero-J.;S. Bacharach
Positron emission tomography (PET) scanners detect pairs of gamma rays resulting from annihilation. PET imagers detect the high‐energy photons produced by the positron annihilation using an electronic detector that comprises a scintillator crystal combined with a photomultiplier. The sensitivity of a PET imager is determined by the product of the geometric efficiency and intrinsic efficiency of the detector. The PET scanner will falsely treat the detection of the two photons as if they resulted from a single annihilation that took place along the line between the two detectors. Such a false coincidence is called an “accidental” or “random” coincidence. Attenuation has significant effects on the results of cardiac PET scans. Quantitatively accurate PET studies require that the number of true coincidences be directly proportional to the concentration of radioactivity. Combining computed tomography with PET imaging is likely to prove more valuable for cardiac imaging than for oncology imaging.
