Value of brain MRI in infective endocarditis: a narrative literature review

Abstract

The nervous system is frequently involved in patients with infective endocarditis (IE). A systematic review of the literature was realized in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). This study sought to systematically evaluate the published evidence of the contribution of brain magnetic resonance imaging (MRI) in IE. The aim was to identify studies presenting the incidence and type of MRI brain lesions in IE. Fifteen relevant studies were isolated using the Medline, Embase, and Cochrane databases. Most of them were observational studies with a small number of patients. MRI studies demonstrated a wide variety and high frequency of cerebral lesions, around 80 % of which were mostly clinically occult. This review shows MRI’s superiority compared to brain computed tomography (CT) for the diagnosis of neurologic complications. Recent developments of sensitive MRI sequences can detect microinfarction and cerebral microhemorrhages. However, the clinical significance of these microhemorrhages, also called cerebral microbleeds (CMBs), remains uncertain. Because some MRI neurological lesions are a distinctive IE feature, they can have a broader involvement in diagnosis and therapeutic decisions. Even if cerebral MRI offers new perspectives for better IE management, there is not enough scientific proof to recommend it in current guidelines. The literature remains incomplete regarding the impact of MRI on concerted decision-making. The long-term prognosis of CMBs has not been evaluated to date and requires further studies. Today, brain MRI can be used on a case-by-case basis based on a clinician’s appraisal.

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

“…MRI characteristics such as the cerebral CMBs, contrast enhancement, and ischemic lesions can be associated with high risk for surgery and a predictor of impending intracranial hemorrhages [7,8,9,10]. In this study, the presence of ischemic stroke, hemorrhagic conversion, CMB <5 mm, or contrast enhancement was not associated with IIAs (online suppl.…”

“…Guidelines recommend DSA when noninvasive tests are negative and suspicion for IIA remains high [5,6]. Magnetic resonance imaging (MRI) characteristics, such as the presence of cerebral microbleeds (CMBs), contrast enhancement, and ischemic lesions, are reported to be associated with high risk for perioperative neurological deterioration due to intracranial hemorrhage, but current evidence remains uncertain [7,8,9,10]. …”

Early Diagnosis of Infective Endocarditis by Brain T2*-Weighted Magnetic Resonance Imaging

“…6, 20 It suggested that the T2*-weighted MRI findings can provide novel, additional criteria for the diagnosis of IE. 2, 11 In our study, 84% of patients had hypointense signal spots on the T2*-weighted images, a value higher than in other studies, 20 but probably attributable to the serious condition of most of the patients, as 84% underwent cardiac surgery. In this group, the abnormal finding on the T2*-weighted MRI may have been indicative of the severity of the disease, …”

Cerebellar abscesses, infective endocarditis and bacteraemia due to a rare pathogen:Streptococcus constellatus

“…When IE is diagnosed, the brain is the first organ involved due to septic emboli from an existing vegetation on a heart valve 9. Neurological symptoms are mild, and the clinical presentation is sometimes paucisymptomatic 10.…”

“…Neurological symptoms are mild, and the clinical presentation is sometimes paucisymptomatic 10. A recent literature review9 showed that MRI is more sensitive than the CT scan in assessing brain involvement when an IE is diagnosed, as most lesions can go undetected in brain CT scans.…”