Hyperacute ischemic stroke: middle cerebral artery susceptibility sign at echo-planar gradient-echo MR imaging

Area of Science:

• Neuroradiology
• Neuroimaging
• Stroke Imaging

Background:

• Acute ischemic stroke diagnosis relies on rapid identification of large vessel occlusion.
• Advanced Magnetic Resonance (MR) imaging techniques are crucial for evaluating stroke etiology.

Purpose of the Study:

• To assess the diagnostic accuracy of echo-planar T2*-weighted MR sequences for detecting acute thrombotic occlusion in the middle cerebral artery (MCA) or internal carotid artery (ICA).

Main Methods:

• Forty-two stroke patients underwent MR imaging within 6 hours of symptom onset, including echo-planar T2*-weighted, diffusion-weighted (DW), perfusion-weighted (PW) imaging, and MR angiography.
• Two blinded observers evaluated for the presence of a susceptibility sign on T2*-weighted images, indicative of MCA or ICA occlusion.
• Lesion volumes on DW and PW images were compared between patients with and without the susceptibility sign.

Main Results:

• A positive susceptibility sign was observed in 71% of patients and correlated with MCA or ICA occlusion (83% sensitivity, 100% specificity).
• Patients with the susceptibility sign showed significantly larger lesion volumes on PW imaging.
• Occlusion proximal to the MCA bifurcation resulted in a mean perfusion deficit of 83.9% of the MCA territory.

Conclusions:

• The susceptibility sign on echo-planar T2*-weighted MR imaging offers a fast and accurate method for detecting acute proximal MCA or ICA thrombotic occlusion.
• This technique aids in the rapid diagnosis of large vessel occlusion in acute stroke patients.