Advanced Imaging of Intracranial Atherosclerosis: Lessons from Interventional Cardiology

Abstract

Intracranial atherosclerosis is a major cause of ischemic stroke. Patients with a high degree of stenosis have a significant rate of stroke despite medical therapy. Two randomized trials of stenting have failed to show benefit. Improving periprocedural complication rates and patient selection may improve stenting outcomes. Fractional flow reserve (FFR), intravascular ultrasound (IVUS), and optical coherence tomography (OCT) are intravascular imaging techniques employed to improve patient selection and stent placement in interventional cardiology. FFR has been shown to improve cardiovascular outcomes when used in patient selection for intervention. Studies of FFR in intracranial atherosclerosis show that the measure may predict which plaques lead to stroke. IVUS is used in cardiology to quantify stenosis and assist with stent placement. Comparisons with histology show that it can reliably characterize plaques. Several case reports of IVUS in intracranial arteries show the technique to be feasible and indicate it may improve stent placement. Plaque characteristics on IVUS may help identify vulnerable plaques. In interventional cardiology, OCT provides excellent visualization of vessel geometry and is useful periprocedurally. Images reliably identify thin-capped fibroatheromas and other plaque features. Case reports indicate that OCT is safe for use in intracranial arteries. OCT can be used to identify perforator vessels and so may be useful in avoiding perforator strokes, a common complication of stenting. Plaque characteristics on OCT may be useful in patient selection.

A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy

“…A growing body of pre-clinical evidence supports the premise that high-resolution cerebrovascular imaging, with the ability to assess vessel wall disease and neurovascular devices, will have a significant impact on the endovascular treatment of cerebrovascular disease [8][9][10]21,29,30 . Recently, it has been shown that in a leporine in vivo model the complete apposition of flowdiverting stents is critically important to achieve early and complete aneurysm occlusion, but histological evidence of poor apposition was not accurately captured on gold-standard DSA imaging 2 .…”

“…Volumetric microscopy with the ability to visualize neurovascular devices in their entirety and the vessel wall microstructure in vivo may have a profound impact in endovascular neurosurgery [8][9][10] . Endoscopic optical-imaging techniques, with a resolution approaching the micron scale and feasible incorporation in small fiber-optics probes, are a promising candidate for a successful translation to the clinic 11,12 .…”

Update in the treatment of intracranial atherosclerotic disease

“…Endovascular intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have recently been used in cerebral artery evaluation to determine plaque characteristics and composition, as well as perforator artery identification 4. More recently, OCT has shown to have better imaging characteristics than IVUS.…”

Intracranial Large Artery Disease of Non-Atherosclerotic Origin: Recent Progress and Clinical Implications

“…Intravascular ultrasound (IVUS) and optical coherence tomography (OCT, the light analog of IVUS) are intravascular imaging techniques used in interventional cardiology [ 48 ]. The results of several case reports suggest that these techniques may provide information for use in the selection of patients with intracranial atherosclerosis who may benefit from stent placement therapy [ 49 ]. These techniques could provide virtual histology to characterize the plaque in large intracranial vessels (distal ICA, VA, and basilar artery).…”