MRI Presentation of Infectious Intracranial Aneurysms in Infective Endocarditis

Abstract

The radiographic appearance of infectious intracranial aneurysms (IIAs) of infective endocarditis (IE) on magnetic resonance imaging (MRI) of brain is varied. We aimed to describe the IIA-specific MRI features in a series of patients with IIAs. Records of patients with active IE who had digital subtraction angiography (DSA) at a tertiary medical center from January 2011 to December 2016 were reviewed. MRIs performed prior to IIA treatment were reviewed for findings on susceptibility-weighted imaging (SWI), diffusion-weighted imaging, and T1 with and without contrast. Of the 732 patients with IE, 53 (7%) had IIAs. Of these, 28 patients had an evaluable pre-treatment MRI, in whom 33 IIAs were imaged. MRI to DSA median time was 1day (interquartile range = 1-5). On MRI, 12 (36%) IIAs had SWI lesion with contrast enhancement, 7 (21%) had cerebral microbleeds, 3 (11%) had sulcal SWI lesion, 2 (6%) IIAs had abscesses, 3 (9%) had intraparenchymal hemorrhage, 3 (9%) had subarachnoid hemorrhage, and 6 (18%) had ischemic stroke at the anatomical locations of IIAs. Four IIAs (12%) had no correlating MRI findings, though those patients had MRI without contrast. The MRI features such as SWI lesion and contrast enhancement were the commonest MRI presentations associated with the presence of IIA.