Magnetic Resonance Imaging Susceptibility-Weighted Imaging Lesion and Contrast Enhancement May Represent Infectious Intracranial Aneurysm in Infective Endocarditis

Abstract

Background: Infectious intracranial aneurysm (IIA) can complicate infective endocarditis (IE). We aimed to describe the magnetic resonance imaging (MRI) characteristics of IIA. Methods: We reviewed IIAs among 116 consecutive patients with active IE by conducting a neurological evaluation at a single tertiary referral center from January 2015 to July 2016. MRIs and digital cerebral angiograms (DSA) were reviewed to identify MRI characteristics of IIAs. MRI susceptibility weighted imaging (SWI) was performed to collect data on cerebral microbleeds (CMBs) and sulcal SWI lesions. Results: Outof 116 persons, 74 (63.8%) underwent DSA. IIAs were identified in 13 (17.6% of DSA, 11.2% of entire cohort) and 10 patients with aneurysms underwent MRI with SWI sequence. Nine (90%) out of 10 persons with IIAs had CMB >5 mm or sulcal lesions in SWI (9 in sulci, 6 in parenchyma, and 5 in both). Five out of 8 persons who underwent MRI brain with contrast had enhancement within the SWI lesions. In a multivariate logistic regression analysis, both sulcal SWI lesions (p < 0.001, OR 69, 95% CI 7.8-610) and contrast enhancement (p = 0.007, OR 16.5, 95% CI 2.3-121) were found to be significant predictors of the presence of IIAs. Conclusions: In the individuals with IE who underwent DSA and MRI, we found that neuroimaging characteristics, such as sulcal SWI lesion with or without contrast enhancement, are associated with the presence of IIA

Cerebral microbleeds predict infectious intracranial aneurysm in infective endocarditis

“…In the derivation cohort, of 62 with MRI scans (from a total of 116 with IE) with SWI and DSA, IIAs were identified in 10 (16% of those with DSA) . In the validation cohort, 19 (15%) IIAs were identified in 129 patients (from a total of 922 with IE) who had both MRI and DSA (Fig.…”

“…The derivation cohort (116 patients) was a subset with brain MRI amongst previously reported consecutive patients with active IE by modified Duke criteria undergoing pre‐operative evaluations for valve surgery with neurological consultation in a single tertiary referral center from 1 January 2015 to 31 July 2016 . The validation cohort consisted of 129 consecutive patients with active IE who underwent DSA and MRI with SWI (or GRE) sequences from 1 January 2010 to 31 December 2014.…”

“…Three criteria from the derivation sample were chosen based on the prior analysis : (i) contrast enhancement with CMBs, (ii) CMBs >5 mm or sulcal SWI lesions and (iii) any MRI hemorrhages. Comparisons of imaging characteristics were performed using Fisher's exact test.…”

“…Recently, a study of 66 persons with IE suggested that cerebral microbleeds (CMBs) in magnetic resonance imaging (MRI) susceptibility‐weighted imaging (SWI) may be a sensitive diagnostic technique for detecting IIA . It has previously been shown that contrast enhancement, CMBs >5 mm, sulcal SWI or gradient‐echo (GRE) lesions and the combination of these three MRI features may predict the presence of IIA . Herein, the aim was to validate these MRI predictors for IIA in order to better assist in assessing the appropriate indications for DSA.…”

Ruptured intracranial infectious aneurysms: Single Canadian center experience

“…One study reports that while the absence of focal neurological deficits or even intracranial hemorrhage had both low sensitivity and specificity for the presence of IIA. [ 4 ]…”