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Effects of attenuation correction and 3D-reconstruction algorithms on brain lesions detectability

We compared lesion detectability in the brain images reconstructed with the three-dimensional (3-D) reprojection algorithm, with and without attenuation correction, and with the 3-D ordered subsets expectation maximization (OSEM) algorithm with and without post-filtering. For this purpose, three small lesion phantoms with diameters of 3, 5 and 8.6 mm were embedded into the Hoffman brain phantom. The approximate ratio of the activity concentration in the lesions to the surrounding brain gray matter was ranging from 1.5 to 10. We used the high-resolution MDAPET, a prototype 3D-PET camera, to scan the phantoms.