ORIGINAL ARTICLES  NEU­RO­PHAR­MA­COL­O­GY 

The Quarterly Journal of Nuclear Medicine 1998 September;42(3):193-8

Copyright © 2000 EDIZIONI MINERVA MEDICA

language: English

Imaging neurochemistry of cerebrovascular disease with PET and SPECT

Hatazawa J., Shimosegawa E.

From the Department of Radiology and Nuclear Medicine Akita Research Institute of Brain and Blood Vessels, Akita, Japan

Pathoph­y­sio­logy of cereb­ro­vas­cular dis­ease has ­been ­studied by meas­uring cere­bral ­blood ­flow and ­energy metab­olism ­using ­single ­photon emis­sion com­puted tomog­raphy (­SPECT) and posi­tron emis­sion tomog­raphy (PET). ­These param­e­ters are meas­ures for ­brain ­tissue con­sisting of het­er­o­ge­neous com­po­nents ­such as neu­rons, ­glial ­cells, and ­blood ves­sels. It is ­still dif­fi­cult to eval­uate ­brain dam­ages spe­cif­i­cally ­involving ­either neu­rons or ­other com­po­nents. Sev­eral ­trials ­were ­recently con­ducted to vis­u­alize ­neuron-spe­cific ­injury in cereb­ro­vas­cular dis­ease by ­means of 11C flu­maz­enil for PET and 123I iomaz­enil for ­SPECT. ­These ­tracers selec­tively ­bind to cen­tral ben­zod­i­az­e­pine ­receptor ­which is ­purely neu­ronal. A ­reduced accu­mu­la­tion of ­these ­ligands was ­found in the ­area sur­rounding the com­plete infarc­tion and in the ­cortex ­remote ­from putam­inal hem­or­rhage, indi­cating the exis­tence of ­neuron spe­cific ­injury not vis­u­al­ized by CT and MR. Neu­ro­log­ical def­i­cits ­were ­well cor­re­lated ­with the ­loss of cor­tical accu­mu­la­tion of ­these ­ligands. ­These pre­lim­i­nary ­studies indi­cated a poten­tial of neu­ro­chem­ical ­imaging in cereb­ro­vas­cular dis­ease. Vul­ner­ability to ­ischemia ­which may ­differ ­among ­brain ­tissue com­po­nents, ­among sub­pop­u­la­tions of neu­rons, and ­among pre­-syn­aptic and ­post-syn­aptic func­tions can be ­more pre­cisely exam­ined. Neu­ro­chem­ical ­imaging can be ­also ­applied to ­reveal ­releases and re-or­gan­iza­tion of ­each neu­ro­trans­mitter-­acceptor ­system ­after ­stroke.