Spect measurements of regional cerebral perfusion and carbondioxide reactivity: correlation with cerebral collaterals in internal carotid artery occlusive disease.
BACKGROUND
The aim of the present study was to assess the regional variation in cerebral perfusion, vasomotor reactivity (VMR) and the role of cerebral collaterals in patients with symptomatic internal carotid artery (ICA).


METHODS
Seventeen functionally independent patients (60+/-9 years, mean+/-SD) with a unilateral symptomatic internal carotid artery occlusion and a <30% contralateral ICA stenosis were investigated. (99 m) Tc-hexamethyl propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) was performed to study cerebral blood flow in rest and during a CO(2) challenge in the cerebellum, temporal lobe, occipital lobe, basal ganglia, frontal lobe and parietal lobe. Time of flight and phase contrast MRA were used to study collateral flow via circle of Willis.


RESULTS
In rest, cerebral perfusion on the side ipsilateral to the ICA occlusion was decreased compared with the contralateral side in the basal ganglia (p<0.05), frontal lobe (p<0.01) and parietal lobe (p<0.01). During a CO(2) challenge only the ipsilateral frontal lobe demonstrated a perfusion decrease compared with the contralateral frontal lobe (p<0.05). Furthermore, in patients without collateral flow via the anterior circle of Willis the perfusion of the ipsilateral frontal lobe was significantly decreased (p<0.01) during the CO(2) challenge and crossed cerebellar diaschisis with a decreased perfusion on the contralateral cerebellar hemisphere was detected (p<0.05). No cerebral blood flow (CBF) differences were found for present/absent collateral flow via the posterior communicating artery.


CONCLUSIONS
Regional assessment of cerebral perfusion and VMR with SPECT demonstrated the heterogeneity of cerebral hemodynamics and the importance of collateral flow via the anterior circle of Willis.
de Boorder
Michiel J
MJ
Department of Radiology, University Medical Center, Utrecht, The Netherlands.
van der Grond
Jeroen
J
van Dongen
Alice J
AJ
Klijn
Catharina J M
CJ
Jaap Kappelle
L
L
Van Rijk
Peter P
PP
Hendrikse
Jeroen
J
D000368:Aged; D002245:Carbon Dioxide / Q000097:blood*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000097:blood / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002941:Circle of Willis / Q000000981:diagnostic imaging / Q000503:physiopathology; D003097:Collateral Circulation / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D002245:Carbon Dioxide; D019690:Technetium Tc 99m Exametazime