Comparative evaluation of cerebral aneurysms with selective arterially enhanced CT and DSA.

The purpose of our study was to compare selective arterially enhanced spiral computed tomographs (ACT) with digital subtraction angiographies (DSA) in the presurgical assessment of cerebral aneurysms. A total of 24 aneurysms in 18 patients were explored in a prospective study by ACT and DSA, using an interactive combined CT-angiography suite. Dimensions of the aneurysm, its relation to the parent vessel, and the aneurysmal index were defined on DSA and on surface-shaded display of 3D reformatted images obtained from ACT. Results were correlated with surgical findings. Three aneurysms suspected on DSA were not confirmed by ACT. One fusiform aneurysm suspected on DSA corresponded to a sacciform aneurysm on ACT. Surgical findings confirmed 20 sacciform aneurysms. The aneurysmal index could be measured in all 20 cases of sacciform aneurysms on ACT and could not be determined with confidence in 55 % of the cases on DSA. DSA and ACT gave identical results in 35 % of cases. In 10 %, the index measured by ACT was superior to that determined by DSA for aneurysms which had a diameter of less than 3 mm. In conclusion, the combination of DSA and ACT improved the results of DSA alone. ACT is a reliable method to measure the aneurysmal index in aneurysms with a diameter superior to 3 mm.

[Spiral tomodensitometry applied to interventional radiology]. / Tomodensitométrie hélicoïdale appliquée à la radiologie interventionnelle.

Spiral CT can be applied to many interventional procedures. Rapid scanning time reduces the duration of percutaneous CT guided biopsy and examination time of polytrauma patients. 3D reconstructions are applied to the planning and follow-up of vascular interventional procedures such as embolization of aneurysms or arteriovenous fistulae, stent grafting of aortic aneurysms or dissection, percutaneous transluminal angioplasty of the renal arteries, supra-aortic or iliac arteries. TIPS, percutaneous biliary procedures and percutaneous treatment of liver tumors do largely benefit from 3D reconstructions as a planning method.