title: Cerebral haemodynamic disturbances in patients with moderate carotid artery stenosis.
abstract: 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.
authors.affiliation: University Department of Radiology, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Trivedi
authors.forename: H A L
authors.initials: HA
authors.lastname: Green
authors.forename: J
authors.initials: J
authors.lastname: U-King-Im
authors.forename: M
authors.initials: M
authors.lastname: Graves
authors.forename: R
authors.initials: R
authors.lastname: Black
authors.forename: P J
authors.initials: PJ
authors.lastname: Kirkpatrick
authors.forename: P D
authors.initials: PD
authors.lastname: Griffiths
authors.forename: J H
authors.initials: JH
authors.lastname: Gillard
mesh_terms: 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
chemical_list: D003287:Contrast Media; D005682:Gadolinium