Object To analyze the incidence and risk factors of microembolic lesions on MR diffusion-weighted imaging (DWI) after endovascular coiling of unruptured intracranial aneurysms (UIA).

Methods We analyzed data obtained from 271 consecutive patients (70 men and 201 women; median age 57 years, range 23–79 years) who presented with UIA for coil embolization between July 2011 and June 2013. Two independent reviewers examined DWI and apparent diffusion coefficient (ADC) maps obtained the following day for the presence of restrictive diffusion spots and counted the number of spots. A multivariate analysis was then performed to identify independent risk factors for developing microembolism following coiling of an aneurysm.

Results Microembolic lesions were noted in 101/271 patients (37.3%). Results of a multivariate analysis showed that the following factors significantly influenced the risk for a microembolism: age, diabetes, previous history of ischemic stroke, white matter FLAIR high signal lesions, multiple aneurysms, and insertion of an Enterprise stent (all ORs > 1.0 and all P-values < 0.05). Previously known risk factors such as prolonged procedure duration, aneurysm size, and decreased antiplatelet function did not show any significant influence.

Conclusion The incidence of microembolism after endovascular coiling of UIA was not low. Lesions occurred more frequently in patients with vascular status associated with old age, diabetes and previous stroke. The multiplicity of aneurysms and the type of stent used for treatment also influenced lesion occurrence.

Disclosures J. Park: None. D. Lee: None. J. Ahn: None. B. Kwun: None.