E1822. Vessel Wall Imaging of Intracranial Aneurysms: A Practical Clinical Review
  1. Andrew Stubenrauch; Ochsner Medical Clinic
  2. Prashant Raghavan; University of Maryland School of Medicine
  3. Dheeraj Gandhi; University of Maryland School of Medicine
  4. Andrew Steven; Ochsner Medical Clinic
Traditional angiographic neuroimaging techniques have focused on imaging flowing blood within a vessel. In recent years, technological developments have allowed sufficient resolution to directly image the vessel wall with magnetic resonance imaging (VW-MRI). This technique allows a more straightforward examination of certain pathologic processes occurring in the wall of the vasculature, rather than nonspecific and indirect inferences based on changes in the size or morphology of the lumen. The utility of this emerging technique continues to be explored, with aneurysm management being of particularly promising potential.

Educational Goals / Teaching Points
The exhibit will include a brief review of the rationale and technical parameters involved with the performance of VW-MRI, along with a balanced review of relevant literature to date. Then through an image rich, case-based presentation illustrates a number of specific clinical scenarios where VW-MRI was helpful in the diagnosis and management of intracranial aneurysms. Multiple real life examples will include both ruptured and unruptured aneurysms. The presentation will include interpretative tips and imaging pitfalls.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The walls of the intracranial vasculature are remarkably thin under physiologic circumstances, with larger vessels like the basilar artery measuring on the order of 0.2 - 0.3mm. Evaluation requires high resolution along with suppression of lumen and CSF signal. Certain disease states can induce wall thickening, signal changes, and enhancement. It has been convincingly demonstrated that the wall of ruptured aneurysms will enhance following the administration of a gadolinium contrast agent. This is believed to reflect some combination of inflammatory cell invasion, neovascularity, and the presence of a vaso vasorum. Serving as an adjunct to traditional angiographic techniques, identification of aneurysm wall enhancement on VW-MRI can have profound influence on patient management in a number of scenarios. However, imaging these minute structures in sick patients can be challenging. A number of potential confounders will be explored including incomplete signal suppression from slow flow or adjacent hemorrhage, patient motion, and nearby veins mimicking arterial wall enhancement.

The purpose of this exhibit is to demonstrate the utility of VW-MRI in the management of patients with intracranial aneurysms.