MRI-Based Classification of Cerebral Hemodynamic Failure With Resting Perfusion Metrics and Cerebrovascular...

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Steno-occlusive disease of major cerebral arteries impairs regional cerebral blood flow (CBF), increasing stroke risk.
• Assessing hemodynamic impairment traditionally requires vasodilatory challenges, with resting perfusion metrics (relative CBF, relative cerebral blood volume, MTT) from CT/MRI used as surrogates.
• Cerebrovascular reactivity (CVR) mapping is a gold standard for evaluating hemodynamic compromise.

Purpose of the Study:

• To compare the diagnostic accuracy of MRI resting perfusion metrics against CVR for detecting hemodynamic insufficiency.
• To evaluate MRI-derived CBF, CBV, and MTT against MRI-based CVR mapping.

Main Methods:

• Noninvasive MRI perfusion metrics were assessed using hypoxia-induced deoxyhemoglobin as contrast.
• Cerebrovascular reactivity (CVR) was measured via blood oxygen level-dependent MRI with a hypercapnic stimulus.
• Twenty-two patients with large artery steno-occlusive disease and healthy controls were included.

Main Results:

• Significant differences in middle cerebral artery perfusion (MTT, relative CBF) and CVR were found between patients and healthy individuals.
• In patients, significant differences were observed between affected and unaffected hemispheres for MTT and CVR.
• Receiver-operator curve analysis indicated CVR was the most sensitive predictor of hemodynamic impairment, followed by MTT.

Conclusions:

• Cerebrovascular reactivity (CVR) demonstrates superior accuracy in assessing hemodynamic impairment compared to resting MRI perfusion metrics.
• CVR serves as a more reliable indicator for identifying patients at risk due to steno-occlusive disease.