In:
Journal of Cerebral Blood Flow & Metabolism, SAGE Publications, Vol. 20, No. 11 ( 2000-11), p. 1587-1603
Abstract:
The single photon emission computed tomography (SPECT) radiotracer [ 123 I]iomazenil is used to assess benzodiazepine receptor binding parameters. These measurements are relative indices of benzodiazepine receptor concentration (B′ max ). To evaluate the ability of such indices in accurately accessing the B′ max the authors compared them with absolute values of B′ max , measured using positron emission tomography (PET). The authors performed SPECT, PET, and magnetic resonance imaging (MRI) studies on a group composed of seven subjects. For SPECT studies, the authors administered a single injection of [ 123 I]iomazenil and estimated the total and specific distribution volumes (DV T SPECT , DV S SPECT ) and the binding potential (BP) using unconstrained (BP SPECT ) and constrained (BP C SPECT ) compartmental models. For PET studies, the authors used a multiinjection approach with [ 11 C]flumazenil and unlabeled flumazenil to estimate absolute values of receptor concentration, B′ max , and some other binding parameters. The authors studied the correlation of different binding parameters with B′ max . To study the robustness of the binding parameter measurements at the pixel level, the authors applied a wavelet-based filter to improve signal-to-noise ratio of time-concentration curves, and the calculated kinetic parameters were used to build up parametric images. For PET data, the B′ max and the DV PET were highly correlated ( r = 0.988). This confirms that it is possible to use the DV PET to access benzodiazepine receptor density. For SPECT data, the correlation between DV SPECT estimated using a two-and three-compartment model was also high ( r = 0.999). The DV T SPECT and BP C SPECT parameters estimated with a constrained three-compartment model or the DV T ″ SPECT parameter estimated with a two-compartment model were also highly correlated to the B′ max parameter estimated with PET. Finally, the robustness of the binding parameters allowed the authors to build pixel-by-pixel parametric images using SPECT data.
Type of Medium:
Online Resource
ISSN:
0271-678X
,
1559-7016
DOI:
10.1097/00004647-200011000-00009
Language:
English
Publisher:
SAGE Publications
Publication Date:
2000
detail.hit.zdb_id:
2039456-1
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