Interventional Neuroradiology - Grants and Awards

Mechanical Clot Obliteration for the Treatment of Stroke (highlighted in the NIBIB eAdvances)

The major goal of this project is to develop and characterize a medical device intended to treat acute ischemic stroke outside of the 3 hour window for pharmacological treatment. Using an ultrasonic thrombectomy wire that produces cavitation streaming leading to obliteration of the fibrin matrix that binds occlusive clots the specific aims of this project are: 1) Test the ability of the device to track and deliver therapeutic ultrasound in vitro in cerebral vascular simulations, 2) Assess immediate safety of therapeutic intracranial ultrasound in an in-vivo canine model, and 3) Assess efficacy of therapeutic intracranial ultrasound in an in-vivo canine model.
Investigative Team: MJ Gounis (PI), AK Wakhloo (co-investigator), JY Chueh (Graduate Student), M Fisher (investigator), MS Albert (investigator).

Figure 1: In Vitro Evaluation of Device Efficacy in a Population Representative Vascular Replica: Baseline, without occlusion (A); middle cerebral artery occlusion by thrombo-embolism (B); and device mediated thrombectomy after 15 minutes of device operation (C). The majority of the clot mass has been obliterated and only minimal flow has been restored to the MCA. Current research is focused on improving the time required ablate the clot and achievement of full flow restoration.

Figure 2: Preclinical Evaluation of Device Safety: A blood vessel map (A) showing the brain arteries where the stroke wire is tested (arrow). Before and after device activation, magnetic resonance imaging (B-E) is obtained to examine how the brain tissue responds to the energy delivered by the wire. Specialized magnetic resonance images show the paths taken by the nerve fibers (B), mean transit time map from perfusion imaging demonstrating blood flow to the brain (C), T2 weighted image showing the brain anatomy (D) and diffusion imaging that is very sensitive to brain tissue death (E) after device operation. These in vivo images (A-E) show no negative tissue response from the use of the device in a brain artery (arrow in D). Histology (G) shows a healthy brain artery following device operation.


Molecular Imaging to Determine the Risk of Rupture of Cerebral Aneurysms

The major goal of this project is to perform exploratory research directed at the testing of the molecular imaging approach using paramagnetic substrates in rabbit model of aneurysm in a 3T MRI setup with an ultimate goal of dramatically improving the ability to differentiate between likely and unlikely candidates for further interventional or surgical procedures. Two major aims are: (1) To optimize rabbit model of aneurysm and correlate MPO activity in rabbit aneurysm with MPO activity in samples obtained from ruptured/unruptured resected human aneurysms and (2) To perform feasibility MR imaging of MPO activity using MPO-specific paramagnetic substrate in experimental inflammatory lesions induced in rabbit aneurysm.
Investigative Team: AA Bogdanov Jr (PI), MJ Gounis (co-investigator), AK Wakhloo (co-investigator), JP Weaver (co-investigator)

Figure 3: Method for inducing perivascular inflammation in a biological model of brain aneurysms.

Figure4 Figure 4: Precontrast (left) and postcontrast (right) MR imaging of the inflamed aneurysm model (arrows) with MPO specific agent. Hyperintensity on the right is related to active inflammation within the aneurysm wall.