@article {Ohba54, author = {Makoto Ohba and Yasuaki Kokubo and Koji Suzuki and Masafumi Kanoto and Yukihiko Sonoda}, title = {Influence of a Headrest on Reconstruction and Attenuation Correction of Human Brain SPECT Images}, volume = {49}, number = {1}, pages = {54--57}, year = {2021}, doi = {10.2967/jnmt.120.244731}, publisher = {Society of Nuclear Medicine}, abstract = {Previous reports suggest that a headrest significantly influences anterior and posterior cerebral blood flow. The present study aimed to clarify the influence of a headrest on reconstruction and attenuation correction (AC) of brain SPECT images. Methods: We evaluated the influence on cerebral blood flow in the anterior region (brain segments A + B), middle region (segments D + F), and posterior region (segment G) of the brain using filtered backprojection{\textendash}AC based on the method of Chang (FBP-ChangAC), ordered-subset expectation maximization{\textendash}ChangAC (OSEM-ChangAC), OSEM CT-based AC (OSEM-CTAC), and OSEM with no attenuation correction (OSEM-NoAC) with and without a headrest. The subjects were 17 healthy volunteers who underwent 99mTc-ECD SPECT. We compared the A + B/G and the D + F/G ratios of 99mTc-ECD SPECT images in each group. Results: For FBP-ChangAC, OSEM-ChangAC, and OSEM-NoAC, there were significant differences in A + B/G ratio between images obtained with a headrest and those obtained without. On the other hand, for OSEM-CTAC, there were no significant differences in A + B/G ratio regardless of whether a headrest was used. For FBP-ChangAC and OSEM-NoAC, there were significant differences in D + F/G ratio between images with a headrest and those without. For OSEM-CTAC and OSEM-ChangAC, there were no significant differences in D + F/G ratio regardless of whether a headrest was used. Conclusion: The influence of a headrest on image reconstruction and AC should be considered if FBP-ChangAC, OSEM-ChangAC, or OSEM-NoAC is used but not if OSEM-CTAC is used.}, issn = {0091-4916}, URL = {https://tech.snmjournals.org/content/49/1/54}, eprint = {https://tech.snmjournals.org/content/49/1/54.full.pdf}, journal = {Journal of Nuclear Medicine Technology} }