Abstract
Previous reports suggest that a headrest significantly influences cerebral blood flow (CBF) in the anterior and posterior regions by image reconstruction and attenuation correction (AC). The present study aimed to clarify the influence of a headrest on the process of reconstruction and AC of brain SPECT images. Methods: We evaluated the influence on CBF in the anterior, middle, and posterior regions of the brain in filtered back projection (FBP)-Chang AC, ordered subset expectation maximization method (OS-EM)-Chang AC, OS-EM-CT-based AC (CTAC), and OS-EM No-AC (no correction for attenuation) with /without a headrest. Subjects were Seventeen healthy volunteers who underwent 99mTc-ECD SPECT. We compared the anterior (A+B)/posterior (G) and the middle region (D+F)/posterior (G) ratios of 99mTc-ECD SPECT images in each group. Results: There are significant differences in A+B/G ratios between with and without a headrest in FBP-Chang AC, OS-EM-Chang AC, and NoAC. On the other hand, there are no significant differences in A+B/G ratios regardless of a headrest in OS-EM-CTAC. There are significant differences in D+F /G ratios between with and without a headrest in FBP-Chang AC, and NoAC. There are no significant differences in D+F /G ratios regardless of a headrest in OS-EM-CTAC and OS-EM-Chang AC. Conclusion: The headrest’s influence on image reconstruction and AC should be considered in FBP-Chang AC, OS-EM-Chang AC, and NoAC except for OS-EM CTAC.
