Magnetic Resonance Imaging of Cerebral Aspergillosis: Imaging and Pathological Correlations.

Guillaume Marzolf,Jean-Philippe Cottier,Francis Schneider,Stéphane Kremer,Meriam Koob,Raoul Herbrecht,David Meyronet,Marcela Sabou,Julie Kreutz,Damien Galanaud,Béatrice Lannes,François Cotton,Maleka Schenck,Sylvie Grand,Nicolas Meyer,Hubert Desal,Jean-Louis Dietemann

doi:10.1371/journal.pone.0152475

Abstract

Cerebral aspergillosis is associated with a significant morbidity and mortality rate. The imaging data present different patterns and no full consensus exists on typical imaging characteristics of the cerebral lesions. We reviewed MRI findings in 21 patients with cerebral aspergillosis and correlated them to the immune status of the patients and to neuropathological findings when tissue was available. The lesions were characterized by their number, topography, and MRI signal. Dissemination to the brain resulted from direct spread from paranasal sinuses in 8 patients, 6 of them being immunocompetent. Hematogenous dissemination was observed in 13 patients, all were immunosuppressed. In this later group we identified a total of 329 parenchymal abscesses involving the whole brain with a predilection for the corticomedullary junction. More than half the patients had a corpus callosum lesion. Hemorrhagic lesions accounted for 13% and contrast enhancement was observed in 61% of the lesions. Patients with hematogenous dissemination were younger (p = 0.003), had more intracranial lesions (p = 0.0004) and had a higher 12-week mortality rate (p = 0.046) than patients with direct spread from paranasal sinuses. Analysis of 12 aneurysms allowed us to highlight two distinct situations. In case of direct spread from the paranasal sinuses, aneurysms are saccular and located on the proximal artery portions, while the hematogenous dissemination in immunocompromised patients is more frequently associated with distal and fusiform aneurysms. MRI is the exam of choice for cerebral aspergillosis. Number and type of lesions are different according to the mode of dissemination of the infection.

Highlights

Aspergillosis is a filamentous fungal infection transmitted by inhalation of airborne spores or by contamination of wounds [1]
Despite the development of Aspergillus galactomannan and the beta-D-glucan detection tests as well as PCR, the mycological data are not always conclusive and imaging modalities such as CT-scan for invasive pulmonary aspergillosis (IPA) and CT combined with MRI for sinus and cerebral aspergillosis are crucial
A review of literature on the MRI appearances of cerebral aspergillosis shows that a few lesions are enhanced after gadolinium injection with a nodular or annular presentation (Table 1) [4,5,6,11,12,13,14,15,16,17,18,19,20,21,22,23]

Summary

Introduction

Aspergillosis is a filamentous fungal infection transmitted by inhalation of airborne spores or by contamination of wounds [1]. This disease develops primarily in immunocompromised patients and may progress to disseminated aspergillosis defined by the infection of at least two noncontiguous organs. A review of literature on the MRI appearances of cerebral aspergillosis shows that a few lesions are enhanced after gadolinium injection with a nodular or annular presentation (Table 1) [4,5,6,11,12,13,14,15,16,17,18,19,20,21,22,23]. The purpose of this study was to describe the variety of MRI presentation of cerebral aspergillosis precisely and to compare these presentations to pathological findings

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