Analysis Of Intracranial Artery Lesions Using 2-D/3D Phase Contrast MR

Using phase contrast MR Angiography with NOVA® Software, this study intends to identify,evaluate and map intracranial aneurysm development as well as develope a predicator for future morphological changes of aneurysms and possible risk of future rupture.

Hemodynamic stress toward the wall of intracranial artery with associated genuine defects of wall remodeling capacity is one of many hypotheses of subarachnoid aneurysm development. In addition, hemodynamic stress toward an aneurysm wall may play a very significant role for the rupture of an aneurysm creating acute Subarachnoid hemorrhage. We think the Wall Shear Stress (WSS) measurement toward an intracranial arterial wall and intracranial aneurysmal wall may provide valuable information for understanding of intracranial aneurysm development as well as predicting future morphological changes of aneurysm and possibly risk of future rupture. This study is significant especially in the management of unruptured subarachnoid arterial aneurysm patients and identifying patients who have higher rupture risks for active treatments such as surgical clipping or coiling to prevent unnecessary but potentially risky procedures.

Gadolinium MR Angiography with NOVA® Software will be used to measure the arterial wall shear stress (WSS) for patients with an intracranial arterial aneurysm. The aneurysm will be identified, blood flow, velocity, volume, vascular diameter and the direction of blood measurements will be taken using NOVA® Software at each point of interest. A WSS map of target intracranial artery and/or aneurysm sac will be created and matched with morphological features providing a clue to understand the the relationships between hemodynamic parameters, especially WSS and morphological changes.

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Inclusion Criteria:

• Unruptured and ruptured adult (>18 years) intracranial arterial aneurysm patients

Exclusion Criteria:

• Less than 18 years old
• Chronic renal failure patients
• Incompetent patient who cannot give consent for routine phase contrast MR Angiography and his/her surrogate decision maker is not available
• Any patients with a contraindication to having a standard MRI examination, such as phase maker, orbital metallic foreign body, etc.