Three-dimensional volume-rendering technique in the angiographic follow-up of intracranial aneurysms embolized with coils

Abstract

The authors conducted a study to evaluate the advantages of a 3D volume-rendering technique (VRT) in follow-up digital subtraction (DS) angiography of coil-embolized intracranial aneurysms. One hundred nine patients with 121 intracranial aneurysms underwent endovascular coil embolization and at least 1 follow-up DS angiography session at the authors' institution. Two neuroradiologists independently evaluated the conventional 2D DS angiograms, rotational angiograms, and 3D VRT images obtained at the interventional procedures and DS angiography follow-up. If multiple follow-up sessions were performed, the final follow-up was mainly considered. The authors compared the 3 techniques for their ability to detect aneurysm remnants (including aneurysm neck and sac remnants) and parent artery stenosis based on the angiographic follow-up. The Kruskal-Wallis test was used for group comparisons, and the kappa test was used to measure interobserver agreement. Statistical analyses were performed using commercially available software. There was a high statistical significance among 2D DS angiography, rotational angiography, and 3D VRT results (X(2) = 9.9613, p = 0.0069) when detecting an aneurysm remnant. Further comparisons disclosed a statistical significance between 3D VRT and rotational angiography (X(2) = 4.9754, p = 0.0257); a high statistical significance between 3D VRT and 2D DS angiography (X(2) = 8.9169, p = 0.0028); and no significant difference between rotational angiography and 2D DS angiography (X(2) = 0.5648, p = 0.4523). There was no statistical significance among the 3 techniques when detecting parent artery stenosis (X(2) = 2.5164, p = 0.2842). One case, in which parent artery stenosis was diagnosed by 2D DS angiography and rotational angiography, was excluded by 3D VRT following observations of multiple views. The kappa test showed good agreement between the 2 observers. The 3D VRT is more sensitive in detecting aneurysm remnants than 2D DS angiography and rotational angiography and is helpful for identifying parent artery stenosis. The authors recommend this technique for the angiographic follow-up of patients with coil-embolized aneurysms.