3D angiography - Clinical interest. First applications in interventional neuroradiology

3D angiography is a true technical revolution that allows improvement in th e quality and safety of diagnostic and endovascular treatment procedures. 3 D angiography images are obtained by reconstruction of a rotational angiogr aphy acquisition done on a C-arm (GE Medical Systems) spinning at 40 degree s per second. The carotid or vertebral selective injection of a total of 15 mi of non-ionic contrast media at 3ml/sec over 5 seconds allows the select ion of the "arterial phase" Pour hundred sixty 3D angiographic studies were performed from December 1996 to September 1998 on 260 patients and have be en analyzed in MIP (Maximum Intensity Projection) and SSD (Shaded Surface D isplay) views. The exploration of intracranial aneurysms is simplified and only requires, for each vascular axis, a biplane PA and Lateral run followe d by a single rotational angiography run. The 3D angiography image is avail able on the workstation's screen (Advantage Workstations 3.1, GE Medical Sy stems) in less than 10 minutes after the acquisition of the rotational run. It therefore allows one to analyze, during the intervention. the aneurysm' s angioarchitecture. in particular the neck, and select the best therapeuti c technique. When endovascular treatment is the best indication, 3D angiogr aphy allows one to define the optimal angle of view and accurately select t he microcoils dimensions. 3D angiography replaces the multiple oblique view s that used to be required to analyze the complex aneurysms and therefore a llows a reduction of the total contrast medium quantity the patient X-ray d ose and the length of the intervention time which is a safety factor. Also in particular for complex cases, it brings additional elements complementin g the results of standard 2D DSA and rotational angiograms. In the cervical vascular pathology, 3D angiography allows for a better assessment of the s tenosis level and of dissection lesions. Our current research activities focus on the matching without stereotactic frame between 3D X-ray angiography and volumetric MR acquisition, which sho uld allow us to improve the treatment of intracerebral arterio-venous malfo rmations (AVMs).