Advanced MR Flow Imaging to Better Identify and Characterize High-Risk Dural Arteriovenous Fistulas
Abstract
Summary of Proposal: This proposal outlines our plan to develop a risk-free method to reliably diagnose and, for the first time, stage the most dangerous vascular malformation in the brain. The proposal is divided into two aims. In Aim 1, we propose to leverage the technology advances of very high magnetic field strength MRI machines to achieve our goals. The MRI machines used in Aim 1 are only available at elite research institutions, but Aim 1 will for the first time provide critical risk-free reliable diagnosis and staging information. Aim 2 shares the same goal as Aim 1, but using MRI machines that are widely available. Aim 2 proposes to provide a tool set that can be disseminated into widespread clinical practice and have an immediate life-saving impact. Background: Dural arteriovenous fistulas (DAVF) are the most dangerous vascular malformations in the brain, with an annual mortality rate as high as 10.4%. DAVF are also common, accounting for 10%-15% all intracranial vascular malformations, and are often a result of head trauma. The main risk of DAVF is of life-threatening bleeding into the brain, for which the risk is about 1 out of 5 each year. Early diagnosis and risk stratification are key to identifying patients for treatment before they experience a catastrophe. Unfortunately, diagnosis is extremely challenging and risk stratification remains impossible on risk-free imaging such as MRI. An invasive procedure, digital subtraction angiography (DSA), is the only reliable method for DAVF diagnosis and the only means for grading. However, DSA is an invasive procedure that has risks including life-threatening stroke, vascular dissection, and exposes patients and operators to potentially harmful radiation. DAVF can basically be divided into high-risk DAVF, or low-risk DAVF based on a finding on DSA called cortical venous drainage (CVD). CVD is reversal of the direction of blood flow in the small veins of the brain. In normal patients and low-risk DAVF, the brain empties blood into the small cortical veins that then drain into the sinus. CVD is when this normal flow pattern is reversed. In CVD, the main sinus harboring the DAVF drains retrograde into the cortical veins. Retrograde drainage from the sinus into the cortical veins pressurizes the cortical veins, impedes normal circulation for the brain, and leads to a catastrophic outcome for patients. About one-third of DAVF have CVD. Early identification of DAVF patients with CVD allows for early treatment. Curing the DAVF, which is predominant through surgery from inside of the blood vessels, alleviates the risks of bleeding. While patients without CVD (low-risk DAVF) have very little risks of intracranial hemorrhage (ICH), they can develop CVD over time, converting to a high-risk fistula. It is currently impossible to predict which DAVF will develop CVD over time. As such, many patients with low-risk DAVF elect to have them treated. Unfortunately, treatment procedures also have significant risks including potentially debilitating or life-threatening stroke. Patients with low-risk DAVF are left with the unfortunate choice between the cumulative risks of continued invasive screening DSA and potential conversion to high-risk DAVF, or to brave the one-time risks of treatment. A risk-free MRI-based technique with improved diagnostic accuracy and the ability to, for the first time, stage DAVF would allow for earlier identification and treatment of the most dangerous DAVFs. This method would also allow for noninvasive monitoring of low-risk DAVF, without the risks of recurring DSA. This would be a significant advance in the field of cerebral vascular malformations that would be immediately impactful in the civilian population as well as populations with higher levels of head trauma, such as military personnel. Rationale: Recent advances in MRI techniques pioneered in our lab over the last several years provide the key technical advances to create an accurate
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 05, 2021
- Source ID
- W81XWH2110753
Entities
People
- Matthew Amans
Organizations
- United States Army
- University of California, San Francisco