Brain perfusion SPECT study with Tc-99m-bicisate: Clinical pitfalls and improved diagnostic accuracy with a combination of linearization and scatter-attenuation correction

To evaluate the usefulness of a combination of linearization and scatter-at tenuation correction on Tc-99m-bicisate (ECD)-single photon emission tomogr aphic (SPECT) images, both cerebral blood flow (CBF)-positron emission tomo graphic (PET) images and ECD-SPECT images from fifteen patients with chroni c cerebral infarction were acquired. We measured radioactivity counts in re gions of interest (ROIs) on all sets of both images and obtained a 2D scatt ered graph between ECD-SPECT and CBF-PET data. To evaluate diagnostic accur acy, the sensitivity, specificity and accuracy of ECD-SPECT images were cal culated by means of discriminant analysis. The same analysis was also perfo rmed on the ECD-SPECT images corrected by a combination of linearization an d scatter-attenuation correction. An overall nonlinear relationship was obs erved between ECD-SPECT and CBF-PET. The sensitivity, specificity, and accu racy of ECD-SPECT images were 69.6%, 91.4% and 73.0%, and those of ECD imag es corrected by the combination of linearization and scatter-attenuation co rrection were 79.5%, 95.7% and 82.0% respectively. The clinically diagnosti c accuracy of ECD-SPECT images corrected by the combined method apparently increased. So that the linearization with the scatter-attenuation method is useful for improving the diagnostic accuracy of ECD-SPECT images.