Abstract
BACKGROUND AND PURPOSE: Elevated OEF is a surrogate for misery perfusion. Our aim was to detect misery perfusion in patients with unilateral steno-occlusive disease of the ICA or MCA by using T2*-based MR imaging and to determine the relationship between brain ischemia and OEF.
MATERIALS AND METHODS: Twenty-three patients with unilateral steno-occlusive disease of the ICA or MCA and 8 healthy volunteers were included in this study. Hemodynamic information was obtained in all subjects by MR imaging. Three regions of interest were placed in the anterior, middle, and posterior parts of the brain bilaterally to measure the OEF and CBF values. The OEFs of the regions of interest in the hemispheres ipsilateral and contralateral to the vascular lesions were compared. Brain regions with OEF greater than that in controls were determined as misery perfusion in patients. The association of vascular lesions, rCBF, and the presence of territory infarction with elevated OEF was investigated.
RESULTS: There was a statistically significant difference in OEF between the ipsilateral and contralateral hemispheres in the patients (t = 3.632, P = .001). Fourteen regions of interest with misery perfusion were determined in the ipsilateral hemispheres, while 3 regions with elevated OEFs were found in the contralateral hemispheres. In the ipsilateral hemispheres, decreased rCBF was associated with elevated OEF (r = −0.451, P < .001). Patients with territory infarction had more regions of interest with misery perfusion than patients without territory infarction (χ2 = 3.889, P = .049).
CONCLUSIONS: By using the MR imaging technique, misery perfusion demonstrated as elevated OEF was detected in patients with severe atherosclerotic ICA or MCA disease. Identification of misery perfusion with MR imaging may be helpful in the evaluation of brain ischemia.
Abbreviations
- ACA
- anterior cerebral artery
- ASL
- arterial spin-labeling
- BOLD
- blood oxygen level–dependent
- CBF
- cerebral blood flow
- DSA
- digital subtraction angiography
- FLAIR
- fluid-attenuated inversion recovery
- GESSE
- gradient-echo sampling spin-echo
- ICA
- internal carotid artery
- MCA
- middle cerebral artery
- MRA
- MR angiography
- OEF
- oxygen extraction fraction
- PET
- positron-emission tomography
- rCBF
- relative cerebral blood flow
- © 2011 by American Journal of Neuroradiology