Related Experiment Videos
Severe occlusive carotid artery disease: hemodynamic assessment by MR perfusion imaging in symptomatic patients
1Department of Radiology, University of Iowa College of Medicine, Iowa City 52242, USA.
Insights
Echo-planar perfusion imaging effectively detects hemodynamic compromise in severe carotid artery disease. This noninvasive method highlights changes in relative mean transit time (rMTT), aiding patient management.
Area of Science:
- Neuroimaging
- Vascular Neurology
- Medical Imaging
Background:
- Cerebral hemodynamic status impacts acute stroke occurrence and outcomes.
- Severe occlusive carotid artery disease poses a significant risk for stroke.
Purpose of the Study:
- To assess hemodynamic compromise in symptomatic patients with severe carotid artery disease.
- To utilize echo-planar perfusion imaging for evaluating these hemodynamic changes.
Main Methods:
- Spin-echo echo-planar perfusion imaging was performed on 11 patients with severe carotid artery stenosis or occlusion.
- Relative cerebral blood volume (rCBV) and relative mean transit time (rMTT) maps were generated.
- Findings were compared qualitatively and quantitatively with T2-weighted images and angiograms.
Main Results:
- rMTT maps revealed significant perfusion abnormalities in affected vascular territories, unlike T2-weighted images.
- No significant decrease in rCBV was observed, though rMTT values differed significantly between affected and unaffected brain tissue.
- Echo-planar perfusion imaging identified hemodynamic compromise not apparent on conventional imaging.
Conclusions:
- Echo-planar perfusion imaging is a noninvasive, rapid tool for evaluating hemodynamics in severe carotid artery disease.
- The technique can detect compensatory vascular changes.
- This method may prove valuable in managing patients with severe occlusive carotid artery disease.
Background And Purpose:
Cerebral hemodynamic status has been reported to influence the occurrence and outcome of acute stroke. The purpose of this study was to assess hemodynamic compromise in symptomatic patients with severe occlusive disease of the carotid artery by the use of echo-planar perfusion imaging.
Methods:
Spin-echo echo-planar perfusion imaging was performed in 11 patients (two had bilateral disease) with severe stenosis or occlusion of the carotid artery who had experienced either a recent transient ischemic attack or minor stroke. Relative cerebral blood volume (rCBV) maps and relative mean transit time (rMTT) maps were generated from the time-concentration curve. Findings on T2-weighted images, angiograms, rCBV maps, and rMTT maps were compared and assessed qualitatively and quantitatively.
Results:
Although the abnormalities on T2-weighted images were absent, minimal, and/or unrelated to the degree of stenosis or collateral circulation, rMTT maps showed much larger and more distinct perfusion abnormalities along the vascular distribution of the affected vessels in all 13 vascular territories of the 11 patients. Despite obvious abnormalities on rMTT maps, none of the patients had evidence of decreased rCBV in the affected brain tissue (increased in three, normal in eight). A statistically significant difference in rMTT values was found between the affected and unaffected brain tissue, whereas no significant difference was seen in rCBV values.
Conclusion:
Echo-planar perfusion imaging is a noninvasive and rapid method for evaluating the hemodynamics in severe occlusive carotid artery disease and the compensatory vascular changes, and it may be useful in patient management.