1.Hemodynamic Significance of Internal Carotid or Middle Cerebral Artery Stenosis Detected on Magnetic Resonance Angiography.
Hyo Jung SEO ; Jefferson R PAGSISIHAN ; Jin Chul PAENG ; Seung Hong CHOI ; Gi Jeong CHEON ; June Key CHUNG ; Dong Soo LEE ; Keon Wook KANG
Yonsei Medical Journal 2015;56(6):1686-1693
PURPOSE: We evaluated hemodynamic significance of stenosis on magnetic resonance angiography (MRA) using acetazolamide perfusion single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Of 171 patients, stenosis in internal carotid artery (ICA) and middle cerebral artery (MCA) (ICA-MCA) on MRA and cerebrovascular reserve (CVR) of MCA territory on SPECT was measured using quantification and a 3-grade system. Stenosis and CVR grades were compared with each other, and their prognostic value for subsequent stroke was evaluated. RESULTS: Of 342 ICA-MCA, 151 (44%) presented stenosis on MRA; grade 1 in 69 (20%) and grade 2 in 82 (24%) cases. Decreased CVR was observed in 9% of grade 0 stenosis, 25% of grade 1, and 35% of grade 2. The average CVR of grade 0 was significantly different from grade 1 (p<0.001) and grade 2 stenosis (p=0.007). In quantitative analysis, average CVR index was -0.56+/-7.91 in grade 0, -1.81+/-6.66 in grade 1 and -1.18+/-5.88 in grade 2 stenosis. Agreement between stenosis and CVR grades was fair in patients with lateralizing and non-lateralizing symptoms (kappa=0.230 and 0.346). Of the factors tested, both MRA and CVR were not significant prognostic factors (p=0.104 and 0.988, respectively), whereas hypertension and renal disease were significant factors (p<0.05, respectively). CONCLUSION: A considerable proportion of ICA-MCA stenosis detected on MRA does not cause CVR impairment despite a fair correlation between them. Thus, hemodynamic state needs to be assessed for evaluating significance of stenosis, particularly in asymptomatic patients.
*Acetazolamide
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Adult
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Aged
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Aged, 80 and over
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Brain/blood supply/radionuclide imaging
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Carotid Artery, Internal/physiopathology/radionuclide imaging
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Carotid Stenosis/physiopathology/*radionuclide imaging
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*Cerebrovascular Circulation
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Constriction, Pathologic
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Diuretics
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Female
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*Hemodynamics
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Humans
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Hypertension/physiopathology
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Iodine Radioisotopes
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*Magnetic Resonance Angiography
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Male
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Middle Aged
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*Radiopharmaceuticals
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Tomography, Emission-Computed, Single-Photon/*methods