Functional CT perfusion imaging in predicting the extent of cerebral infarction from a 3-hour middle cerebral arterial occlusion in a primate stroke model.
OBJECTIVE
Our purpose was to determine whether cerebral perfusion functional CT (fCT), performed after endovascular middle cerebral artery (MCA) occlusion, can be used to predict final cerebral infarction extent in a primate model.


METHODS
fCT with bolus tracking was performed before and 30 and 150 minutes after 3-hour digital subtraction angiography (DSA)-guided endovascular MCA occlusion in five baboons. Parametric cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps were constructed by voxel-by-voxel gamma variate fitting and used to determine lesion sizes. Animals were sacrificed 48 hours after the occlusion, and ex vivo MR imaging was performed. Lesion sizes on fCT and MR images were compared.


RESULTS
Hypoperfusion was clearly identified on all images obtained after MCA occlusion. Thirty and 150 minutes after occlusion onset, respectively, mean lesion sizes were 737 mm(2) +/- 33 and 737 mm(2) +/- 44 for CBF, 722 mm(2) +/- 32 and 730 mm(2) +/- 43 for CBV, and 819 mm(2) +/- 14 and 847 mm(2) +/- 11 for MTT. Mean outcome infarct size on MR images was 733 mm(2) +/- 30. Measurements based on CBV and CBF (R(2) = 0.97 and 0.96, P <.001), but not MTT (R(2) = 0.40, P >.5), were highly correlated with final lesion size.


CONCLUSIONS
An endovascular approach to MCA occlusion provides a minimally invasive, reproducible animal model for controlled studies of cerebral ischemia and infarction. Derived cerebral perfusion maps closely predict the 48-hour infarct size after 3-hour MCA occlusion.
Hamberg
Leena M
LM
MGH Perfusion and Physiology Analysis Laboratory, Department of Neuroradiology, the Massachusetts General Hospital and Harvard Medical School, Boston 02114, USA.
Hunter
George J
GJ
Maynard
Kenneth I
KI
Owen
Chris
C
Morris
Pearse P
PP
Putman
Christopher M
CM
Ogilvy
Christopher
C
González
R Gilberto
RG
D015901:Angiography, Digital Subtraction; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001810:Blood Volume; D002545:Brain Ischemia / Q000209:etiology; D002533:Cerebral Angiography; D002536:Cerebral Arteries; D002544:Cerebral Infarction / Q000209:etiology*; D002560:Cerebrovascular Circulation; D004195:Disease Models, Animal; D005544:Forecasting; D008279:Magnetic Resonance Imaging; D010215:Papio; D020521:Stroke / Q000209:etiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed