Cerebral haemodynamic disturbances in patients with moderate carotid artery stenosis.
OBJECTIVE
Dynamic MR perfusion imaging can detect cerebral perfusion deficits resulting from severe internal carotid artery (ICA) stenosis. It is unknown, however, whether moderate ICA stenosis (50-69%) also causes haemodynamic disturbance. We investigated whether cerebral perfusion deficits were detectable in patients with moderate ICA stenosis.


METHODS
Eighteen patients underwent T2* weighted cerebral MR perfusion imaging with a gadolinium based contrast agent. Differences in mean time to peak (mTTP) and relative cerebral blood volume (rCBV) between cerebral hemispheres were calculated for middle cerebral artery territory regions by a reader blinded to the angiographic and clinical findings.


RESULTS
There were significant differences in mTTP between cerebral hemispheres in 15 patients with a mean inter-hemispheric delay in mTTP of 0.49 s (95% confidence intervals, 0.25 and 0.72 s) which was statistically significant ( p <0.001). In 1 patient with bilateral moderate stenosis there was no difference in mTTP.


CONCLUSIONS
Moderate ICA stenosis results in significant ipsilateral cerebral perfusion delays detectable by dynamic susceptibility MRI. Follow-up studies might reveal whether these delays improve following carotid endarterectomy.
Trivedi
R A
RA
University Department of Radiology, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK.
Green
H A L
HA
U-King-Im
J
J
Graves
M
M
Black
R
R
Kirkpatrick
P J
PJ
Griffiths
P D
PD
Gillard
J H
JH
D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media / Q000494:pharmacology; D005260:Female; D005682:Gadolinium; D006439:Hemodynamics; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method
D003287:Contrast Media; D005682:Gadolinium