Significance of the perfusion-diffusion mismatch in chronic cerebral ischemia.
OBJECTIVE
To determine whether the perfusion deficit could predict brain infarction in patients with chronic cerebral ischemia who experienced recurring episodes of neurological symptoms and showed a perfusion-diffusion mismatch on magnetic resonance (MR) images.


METHODS
In 53 consecutive patients (38 males and 15 females, 62+/-13 years old) with ischemia in the middle cerebral artery (MCA) territory, lesion volumetry was performed on parametric maps of the time-to-peak, the cerebral blood volume, and diffusion-weighted (DW) images. The infarct lesions were assessed on follow-up T2-weighted (T2W) MR images after eight days. Cerebrovascular changes were determined by time-of-flight (TOF) MR angiography (MRA). Inferential and correlation statistics were used.


RESULTS
Patients with chronic ischemic brain disease (N=39) who presented with a severe perfusion-diffusion mismatch in the presence of a normal cerebral blood volume had no or small brain infarctions as found on follow-up T2W images. MRA revealed widespread abnormalities of the basal cerebral arteries compatible with brain perfusion abnormalities. In contrast, in acute stroke patients (N=14) the deficit of cerebral perfusion predicted the infarct lesion in the T2W images.


CONCLUSIONS
Our results suggest that in chronic cerebral ischemia the normal blood volume was maintained despite the depression of cerebral perfusion and recurring minor insults.
Surikova
Irina
I
Department of Neurology, Heinrich Heine University, Düsseldorf, Germany.
Meisel
Stefanie
S
Siebler
Mario
M
Wittsack
Hans-Jörg
HJ
Seitz
Rüdiger J
RJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology; D002545:Brain Ischemia / Q000503:physiopathology*; D002544:Cerebral Infarction / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D018709:Statistics, Nonparametric
D003287:Contrast Media; D019786:Gadolinium DTPA