Semiquantifying regional cerebral blood flow by 123I-amphetamine (IMP) SPECT in cerebrovascular disorders: Correlations with CBF indices by 133Xe inhalation method

To examine the capacity of detecting regional cerebral blood flow (rCBF) disturbances in stroke, measurements with ¹³³Xe inhalation and ¹²³I-amphetamine (IMP) SPECT were performed within 1–2 days in 19 patients. IMP SPECT images in transverse sections consisting of outer and inner areas were correlated with 32 regions of ¹³³Xe rCBF. ¹³³Xe rCBF was assessed by ISI, CBF₁₅, and F₁. Inter hemispheric ratio correlation showed outer IMP uptake correlated better with ¹³³Xe CBF indices than the inner one. With higher ratios of ¹³³Xe rCBF, IMP uptake ratios were variable, suggesting less usefulness of this parameter in evaluation of mild ischemia. Values of IMP in outer regional hypo and hyperemic areas correlated better with those of ¹³³Xe rCBF than the inner ones. In regional ratios of hypo and hyperemic areas from hemispheric mean, outer IMP uptake correlated with ¹³³Xe CBF indices, reflecting regional disturbances of fast clearing tissue perfusion. Regression lines between ratios in ¹³³Xe CBF and IMP uptake were located below one to one correlation, and dissociated more for hyperemic regions. IMP SPECT correlated better with ¹³³Xe rCBF for tissues with reduced perfusion but underestimated hyperemic regions as measured with the ¹³³Xe method. The data suggest outer cerebral IMP uptake evaluated by SPECT could reflect flow disturbances in the brain cortex.This paper was presented in part at the XIIIth International Salzburg Conference on Cerebral Vascular Disease, on Sept. 25–27, 1986, in Salzburg, Austria, and at the XIIIth International Symposium on Cerebral Blood Flow and Metabolism, on June 21–25, 1987, in Montreal, CanadaRecipient of a Research Fellowship from the Alexander-von-Humboldt-Foundation, Federal Republic of Germany; Present address: Second Department of Internal Medicine, Kagawa Medical University, 1750-1 Ikenobe, Miki-cho, 761-07 Kagawa, Japan