Preliminary results of Tc-99m ECD SPECT to evaluate cerebral collateral circulation during balloon test occlusion.
OBJECTIVE
The authors obtained noninvasive quantitative measurements of regional cerebral blood flow using Tc-99m L,L-ethyl cysteinate dimer (Tc-99m ECD) SPECT to evaluate cerebral collateral circulation during balloon test occlusion (BTO) of the internal carotid artery and vertebral artery (VA).


METHODS
Five cases associated with an aneurysm and a brain tumor were investigated. After 10 minutes of BTO, a bolus of Tc-99m ECD was injected intravenously and radionuclide angiography was performed. The balloon remained inflated for an additional 5 minutes. After radionuclide angiography was completed, brain SPECT imaging was performed. For quantitative analysis, regions of interest were defined on the transverse images on each side of the anterior cerebral artery and middle cerebral artery territories in cases of occlusion of the internal carotid artery. Regions of interest were defined for the posterior cerebral artery territory and cerebellum in cases of occlusion of the VA. The percentage activity change during BTO was calculated.


RESULTS
In two of the three patients in whom BTO of the internal carotid artery was performed, the percentage activity reduction of more than 30% was noted in the anterior cerebral and middle cerebral artery territories. These two patients underwent bypass grafting before carotid occlusion. In one of the two patients in whom BTO of the VA was performed, the percentage activity reduction of 16% was noted in the posterior cerebral artery territory. This patient underwent bypass grafting before occlusion of the VA.


CONCLUSIONS
This noninvasive and quantitative method of cerebral blood flow measurement using Tc-99m ECD during BTO appears to have the potential to help select patients who may tolerate temporary or permanent arterial occlusion.
Department of Radiology, Faculty of Medicine, Kagawa Medical University, Japan. yuka@kms.ac.jp
Yuka
Y
Yamamoto
Yoshihiro
Y
Nishiyama
Yoshihiro
Y
Toyama
Katashi
K
Satoh
Keiko
K
Irie
Motoomi
M
Ohkawa
D021721:Balloon Occlusion / Q000379:methods*; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation; D003097:Collateral Circulation; D003323:Coronary Aneurysm / Q000000981:diagnostic imaging / Q000628:therapy; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging; D008579:Meningioma / Q000098:blood supply / Q000000981:diagnostic imaging; D008875:Middle Aged; D015609:Organotechnetium Compounds; D011300:Preoperative Care / Q000379:methods; D011875:Radionuclide Angiography / Q000379:methods; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon; D014711:Vertebral Artery / Q000000981:diagnostic imaging
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine