ORIGINAL RESEARCH 3D Rotational Angiography: The New Gold Standard in the Detection of Additional

BACKGROUND AND PURPOSE: The purpose of this study was to compare 3D rotational angiography (3DRA) and digital subtraction angiography (DSA) in the detection of small additional intracranial aneurysms. MATERIALS AND METHODS: Three hundred fifty 3D datasets of 1 vascular tree of 350 patients with at least 1 intracranial aneurysm on the dataset were re-evaluated for the presence of additional aneu-rysms by 2 observers in consensus. Two other observers, blinded to the 3D images, re-evaluated DSA images of the same 350 vascular trees for these additional aneurysms. Results were compared. RESULTS: In 350 3D datasets, 350 target aneurysms and 94 additional aneurysms were detected. The mean size of 94 additional aneurysms was 3.54 mm (median, 3; range, 0.5–17 mm). The proportion of aneurysms 3 mm was significantly higher in additional aneurysms (61 of 94, 65%) than in the target aneurysms (61 of 350, 17%) (2, P .0001). Of 94 additional aneurysms, 27 (29%) were missed on DSA by both observers. The mean size of the missed aneurysms was 1.94 mm (median, 2; range, 0.5–4 mm). The proportion of aneurysms3 mm in missed additional aneurysms (26 of 27, 96%) was significantly higher than that in all additional aneurysms (61 of 94, 65%) (2, P .0035). The location of missed additional aneurysms was not different from the location of all additional aneurysms. CONCLUSION: 3DRA depicts considerably more small (3 mm) additional aneurysms than DSA. I