Perfusion and diffusion MR imaging of thromboembolic stroke.
A carotid embolic stroke model in rats was studied with a combination of diffusion- and perfusion-sensitive magnetic resonance (MR) imaging at 4.7 T. Capillary blood deoxygenation changes were monitored during formation of focal ischemia by acquiring multisection magnetic susceptibility-weighted echo-planar images. A signal intensity decrease of 7% +/- 3 in ischemic brain (1% +/- 2 in normal brain) was attributable to a T2* decrease due to increased blood deoxygenation, which correlated well with subsequently measured decreases in the apparent diffusion coefficient. The same multisection methods were used to track the first-pass transit of a bolus of dysprosium-DTPA-BMA [diethylenetriaminepentaacetic acid-bis(methylamide)] to assess relative tissue perfusion before and after stroke and after treatment with a thrombolytic agent. Analysis of contrast agent transit profiles suggested a total perfusion deficit in ischemic tissue and essentially unchanged perfusion in normal brain tissue after stroke.
Department of Radiology, University of California, San Francisco 94143.
A J
AJ
de Crespigny
M
M
Tsuura
M E
ME
Moseley
J
J
Kucharczyk
D000818:Animals; D002341:Carotid Artery Thrombosis / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D002342:Carotid Artery, External; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D004419:Dysprosium; D017352:Echo-Planar Imaging; D002546:Ischemic Attack, Transient / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D009942:Organometallic Compounds; D010100:Oxygen / Q000097:blood; D004369:Pentetic Acid / Q000031:analogs & derivatives; D051381:Rats; D017207:Rats, Sprague-Dawley; D015912:Thrombolytic Therapy
D003287:Contrast Media; D009942:Organometallic Compounds; C061756:sprodiamide; D004419:Dysprosium; D004369:Pentetic Acid; D010100:Oxygen