Basic research on methods of evaluating localized brain perfusion applying the registration function in brain perfusion SPECT. Application of iNRT

A fundamental study to estimate brain perfusion SPECT (single photon emission computed tomography) was performed using the registration function of the iNRT brain perfusion image display program. A mixture of 99mTc and 111In were injected into the brain phantom. Three line sources were placed on the phantom for a landmark. Accumulation of the two radionuclides in the phantom was measured, then again when it was rotated and when the SPECT images were moved in different directions to estimate the dimensional displacement found in clinical cases. The subtraction images proved that multi-directional dimensional displacement could be automatically corrected. Clinically, for internal carotid artery obstruction, dimensional displacement could be corrected by comparing registered exercised brain perfusion SPECT with acetazolamide with a baseline study performed on a different day. And a method to easily estimate regional perfusion reserves could be established from the subtraction images. (author)