Performance Evaluation and Initial Clinical Test of the Positron Emission Mammography System (PEMi)

摘要: A new polygon positron emission mammography imaging system (PEMi) was developed in 2009 by the Institute of High Energy Physics, Chinese Academy Sciences. PEMi is constructed a structure with lutetium yttrium orthosilicate crystal arrays mounted on position-sensitive photomultiplier. The consists 64 blocks and each block arranged $16 \times 16$ pixel size $1.9~\times 1.9~ 15$ mm. diameter detector ring 166 mm, axial length 128 mm. transaxial field view 110 mm. goal initial study to test PEMi’s performance clinical ability small group selected subjects. detectors have measured intrinsic spatial resolution averaging 1.67 mm. tangential remained under 2.5-mm full width at half maximum within central 5-cm view. hot rods 1.7 mm can be clearly identified, region containing 1.35-mm also observed. Using 6-ns coincidence timing window ${\hbox {360}} \sim {\hbox {660}}$ -keV energy window, peak sensitivity tomograph 6.88%. noise-equivalent count rate 110 $\thinspace$ 766 cps for breast-like cylindrical phantom 100 mm an activity concentration $0.03~\hbox{MBq}/{\rm cc}$ . recovery coefficients ranged from 0.21 0.85 between 1 mm 5 mm image-quality phantom. reconstructed image achieved improvement compared whole-body tomography (PET), which might reduce lower threshold detectable lesion size. Example patient images demonstrate that clinically feasible. And more detailed information obtained than PET imaging.