[Noninvasive quantitative measurements of regional cerebral blood flow using technetium-99m-L, L-ECD SPECT activated...

To evaluate noninvasive regional cerebral blood flow (CBF) measurements using technetium-99m-L, L-ethyl cysteinate dimer (99mTc-ECD), radionuclide angiography, resting- and acetazolamide-activating-SPECT studies were performed during about one hour. Forty-four cases with diagnosis of cerebral ischemic disorders were studied. For 36 cases (Group "Acz"), radionuclide angiography was performed immediately after intravenous bolus injection of 300 MBq of 99mTc-ECD, followed by the consecutive SPECT studies. In the midst of the first SPECT study, acetazolamide was administered. Just after the completion of the first SPECT study, another 300 MBq of 99mTc-ECD was added and the second SPECT study was started. For the remaining 8 cases (Group "Placebo"), physiological saline was administered instead of acetazolamide. Quantitative flow-mapping image was calculated from the qualitative SPECT image by the application of Patlak plot graphical analysis and Lassen's correction. Group "Placebo" showed no increase of mean CBF (mCBF) between the resting- and the placebo-challenged-SPECT image (2nd mCBF/1st mCBF; 98 +/- 5%). Group "Acz" showed 124 +/- 15% increase of mCBF under acetazolamide activation. By use of these quantitative flow-mapping images, acetazolamide-activated CBF increase was recognized clearly and easily. This noninvasive method is easy to perform and may be helpful to measure cerebral perfusion changes in the acetazolamide test.