Usefulness of computed tomography and magnetic resonance in fulminant invasive fungal rhinosinusitis

Fulminant invasive fungal rhinosinusitis is an aggressive, destructive process most commonly affecting the immunocompromised host. Although frequently fatal, prognosis is related directly to early recognition and aggressive treatment. Various reports advocate computed tomography (CT) scanning as the study of choice in evaluating suspected invasive fungal disease, reserving magnetic resonance imaging (MRI) for select cases. Others report lack of correlation between CT and surgical or pathological findings. Our aim was to investigate the usefulness of CT and AIR in the diagnosis of invasive fungal rhinosinusitis. We retrospectively reviewed four cases of biopsy-proven invasive disease. Correlations between radiographic, endoscopic, and surgical findings were investigated. Rhizopus species were detected in three cases and mixed Mucor and Aspergillus species in another. Superimposed bacterial sinusitis was confirmed in all cases. CT findings were nonspecific, revealing pansinusitis; no bone destruction or intracranial extension was noted. Mild orbital cellulitis was noted in one case. Anterior rhinoscopy revealed nonviable tissue in two patients. Nasal endoscopy later confirmed tissue ischemia in a third patient, whereas a final patient had normal findings on both examus. Nonspecific findings resulted in delay of diagnosis by 48-72 hours in two patients with presumed bacterial sinusitis. MR revealed intracranial extension in two patients and better represented intraoperative findings. In conclusion, CT findings in invasive fungal rhinosinusitis may be nonspecific and underestimate extent of disease. A high index of suspicion and early endoscopic examination with biopsy are mandatory for evaluation. MRI may better represent disease progression and should be considered early.