Computed tomography and magnetic resonance imaging characteristics of acute invasive fungal sinusitis.

OBJECTIVE: To determine radiographic findings on computed tomography (CT) and magnetic resonance imaging (MRI) predictive of acute fulminant invasive fungal sinusitis (AFIFS) in an immunocompromised patient population.

DESIGN: Retrospective case-control study.

SETTING: Tertiary referral hospital.

PATIENTS: Cases were 17 immunocompromised patients with confirmed AFIFS after surgical debridement or biopsy. Controls were 6 immunocompromised patients histopathologically negative for AFIFS after surgical debridement or biopsy.

MAIN OUTCOME MEASURES: Computed tomographic and MRI scans were independently reviewed by 2 neuroradiologists to identify imaging characteristics predictive of AFIFS. Operative reports and histopathologic, microbiologic, and survival data were reviewed.

RESULTS: No significant differences with regard to baseline characteristics between the 2 groups were identified. There was moderate or substantial agreement (κ = 0.40-0.77) between the 2 radiologists for all imaging parameters except MRI loss of contrast enhancement (κ = 0.16). Magnetic resonance imaging was more sensitive than CT for the diagnosis of AFIFS (sensitivity 85% and 86% for both reviewers compared with 57% and 69%). Extrasinus invasion with MRI was the most sensitive individual parameter (87% and 100%). Magnetic resonance imaging and CT had similar specificities, and perisinus invasion was the most specific individual parameter (83% and 83% for MRI compared with 81% and 83% for CT). The positive predictive values were high for both imaging modalities (93% and 94% for MRI compared with 89% and 93% for CT). The negative predictive values were lower for both modalities and varied more between reviewers (71% and 100% for MRI compared with 45% and 67% for CT).

CONCLUSIONS: Magnetic resonance imaging is more sensitive for detecting early changes of AFIFS than CT. Both imaging modalities have similar specificities. Perisinus invasion with MRI was the most sensitive and specific single parameter evaluated.