Measurement of cerebral hemodynamics with perfusion-weighted MR imaging: comparison with pre- and post-acetazolamide 133Xe-SPECT in occlusive carotid disease.
OBJECTIVE
We generated regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF) studies from dynamic susceptibility contrast-enhanced MR images after an intravenous bolus injection of contrast agent (perfusion-weighted imaging [PWI]) by applying indicator dilution theory. We used a multishot echo-planar imaging (EPI) sequence to obtain adequate arterial input function (AIF). Our purpose was to compare the cerebral hemodynamics measured by PWI with the rCBF values and cerebral perfusion reserve obtained by xenon-133 single-photon emission CT (133Xe-SPECT).


METHODS
Eight patients with chronic internal carotid artery occlusion or stenosis were examined. PWI data were acquired using a multishot EPI sequence, and the AIF was determined automatically. Our procedure was based on indicator dilution theory and deconvolution analysis. To eliminate the effect of superficial vessels, the automatic threshold selection method was used.


RESULTS
AIF was adequate to generate rCBF and rCBV images. The rCBF and rCBV images by PWI were superior to 133Xe-SPECT scans in spatial resolution, and the rCBF values obtained by PWI correlated well with those obtained by 133Xe-SPECT. The regions with severely decreased perfusion reserve, which were determined by pre- and post-acetazolamide 133Xe-SPECT, showed significantly lower rCBF and higher rCBV by PWI than did regions with normal and moderately decreased perfusion reserve.


CONCLUSIONS
The rCBF and rCBV images generated by our procedure using PWI data appear to provide important clinical information for evaluating the degree of cerebral perfusion reserve impairment in patients with chronic ischemia.
Kikuchi
K
K
Department of Radiology, Ehime University School of Medicine, Japan.
Murase
K
K
Miki
H
H
Kikuchi
T
T
Sugawara
Y
Y
Mochizuki
T
T
Ikezoe
J
J
Ohue
S
S
D000086:Acetazolamide; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000503:physiopathology*; D001810:Blood Volume; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000175:diagnosis / Q000503:physiopathology; D002536:Cerebral Arteries / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes; D000086:Acetazolamide