Endoluminal Diagnosis of Cerebral Aneurysms with Virtual Vascular Endoscopic Imaging of 3D-MR Angiography

Abstract

Endoluminal evaluation was done with virtual vascular endoscopic imaging(VVE)using perspective volume rendering of 3D-MR angiography in 4 cases of unruptured cerebral aneurysms. Virtual endoluminal observation of the aneurysms in relation to their parent arteries was done from inside the parent arteries or in the intra-aneurysmal space. VVE delineated the orifices of the cerebral aneurysms and intra-aneurysmal spaces through the parent arteries. In a patient with a middle cerebral artery aneurysm, the direct opening of the efferent parent artery from the dome of the aneurysm was clearly demonstrated. Images of the aneurysms from the intra-aneurysmal space delineated the concave bleb of the inner wall of the aneurysms and the orifices of the parent arteries at the neck of the aneurysms. In a large aneurysm, the intra-aneurysmal structure may be incomplete due to flow artifact of the source volume data set. Viewing points are indicated by arrows shown either on the source axial images, reconstructed coronal and sagittal images, and reconstructed volume-rendering three-dimensional MR angiograms. These images provided the precise endoluminal orientation of VVE. The software we used shortened the reconstruction time(30 sec)to facilitate the clinical applications of VVE. As an alternative to "real" .intravascular endoscopy, VVE imaging of 3D-MRA may have a role in preoperative evaluation and simulation of interventional procedures, such as GDC coil embolization of cerebral aneurysms. Additionally, observation of the orifies of parent arteries and intra-aneurysmal spaces with VVE may be useful for the endoluminal diagnosis of cerebral aneurysms.