SPECT images of technetium-99m-ethyl cysteinate dimer in cerebrovascular diseases: comparison with other cerebral perfusion tracers and PET.
To assess the clinical role of 99mTc-ethyl cysteinate dimer (ECD) as a cerebral perfusion tracer, 10 patients with unilateral cerebral infarction were studied.


METHODS
ECD SPECT images were compared with IMP and/or HMPAO SPECT in nine patients, seven in chronic phases and two in subacute phases. Five of these patients and one additional patient with chronic infarction received PET imaging in order to compare ECD distribution with quantitative regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2) images.


RESULTS
In patients with chronic cerebral infarction, regression analysis showed excellent correlation between ECD and IMP in the uptake ratio of lesions-to-nonaffected cortices (r = 0.91). In two cases of subacute infarction, decreased uptake of ECD was observed in the area of "luxury perfusion," which showed elevated or preserved rCBF with diminished rCMRO2. On visual analysis, ECD image contrast was less prominent compared to that of IMP, but contrast was better than that of HMPAO.


CONCLUSIONS
ECD uptake showed a curvilinear relationship against rCBF, suggesting flow-limited uptake in a high flow range. ECD is a clinically useful cerebral perfusion tracer with distinct characteristics when compared with other available agents.
Tsuchida
T
T
Department of Nuclear Medicine, Kyoto University Faculty of Medicine, Japan.
Nishizawa
S
S
Yonekura
Y
Y
Sadato
N
N
Iwasaki
Y
Y
Fujita
T
T
Matoba
N
N
Magata
Y
Y
Tamaki
N
N
Konishi
J
J
D000328:Adult; D000662:Amphetamines; D001921:Brain / Q000000981:diagnostic imaging; D002544:Cerebral Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D020367:Iofetamine; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D000662:Amphetamines; D003287:Contrast Media; D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D020367:Iofetamine; C059659:technetium Tc 99m bicisate; D003545:Cysteine