Preoperative Digital Subtraction Angiography in Incidental Unruptured Intracranial Aneurysms: How Much is too Much?

Purpose Digital subtraction angiography (DSA) is deemed necessary to precisely visualize intracranial aneurysms and define individual treatment strategies. In patients with unruptured intracranial aneurysms (UIA) who were diagnosed by MRI, a four-vessel DSA is usually performed to detect additional aneurysms. This study aimed to evaluate whether the evaluation of all vessels beyond the aneurysm-harboring artery is really necessary. Material and methods Patients with an UIA that was detected on MRA (TOF/ceMRA) were prospectively included. All patients underwent a four-vessel DSA (including 3D-DSA) and two experienced neuroradiologists independently analyzed the MRI sequences before DSA. The number of aneurysms, size and anatomic localization were documented and correlated with the angiographic findings. Results The DSA revealed a total of 134 aneurysms in 106 patients. Overall sensitivity and negative predictive value of MRA were 95.6% and 95.6%, respectively. In patients with multiple (≥2) aneurysms, 4 very small aneurysms