Ratio-Images Calculated From Interictal Positron Emission Tomography and Single-Photon Emission Computed Tomography for Quantification of the Uncoupling of Brain Metabolism and Perfusion in Epilepsy

Autor: Corsi M, Robert A. Avery, Colin Studholme, I. G. Zubal, Rik Stokking, Dey H, John Seibyl, Susan S. Spencer
Rok vydání: 2000
Předmět:
Zdroj: Scopus-Elsevier
ISSN: 1528-1167
0013-9580
DOI: 10.1111/j.1499-1654.2000.001560.x
Popis: Purpose: Image processing techniques were applied to interictal positron emission tomography (PET) and single-photon emission computed tomography (SPECT) brain images to aid in the localization of epileptogenic foci by calculating a functional image that represents the degree of coupling between perfusion and metabolism. Uncoupling of these two functions has been demonstrated to be a characteristic of epileptogenic tissue in temporal lobe epilepsy and has the potential to serve as a diagnostic measure for localization in other areas as well. Methods: Interictal PET ( 18 F-FDG) and interictal SPECT ( 99m Tc-HMPAO) scans were acquired from 11 epilepsy patients. The metabolism and perfusion images were three-dimensionally spatially registered, and a functional ratio-image was computed. These functional maps are overlaid onto a three-dimensional rendering of the same patient's magnetic resonance imaging anatomy. Results: In all patients, an average uniform perfusion-to-metabolism ratio showed approximately constant values throughout most of the whole brain. However, the epileptogenic area (confirmed on surgery) demonstrated an area of elevated perfusion/metabolism in the grey matter. Conclusions: Although hypometabolism in the PET image was observed in most of these patients, the calculation of a functional ratio-image demonstrated localized foci that in some cases could not be observed on the PET image alone. The ratio-image also yields a quantitative measure of the uncoupling phenomenon.
Databáze: OpenAIRE
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