Utilizing CT soft-tissue markers as a screening tool for acute invasive fungal sinusitis

Acute invasive fungal sinusitis (AIFS) is a rapidly progressive disease, whose delayed identification results in poor outcomes, especially in immunocompromised individuals. A surge in of AIFS in the wake of the COVID-19 pandemic has lent additional morbidity and mortality to an already precarious clinical scenario. Early detection of AIFS in individuals who are symptomatic/ at risk can allow early therapy, enabling better patient outcomes. Our study aims to determine optimal soft-tissue markers on CT for the early detection of AIFS.

In this case-control study, 142 patients with equal distribution of subjects were chosen based on histopathological diagnosis of AIFS; and their non-contrast CT scans were retrospectively assessed to determine the diagnostic utility of specific soft-tissue markers that would enable diagnosis of AIFS.

A total of nine markers with adequate sensitivity and specificity were identified, including pterygopalatine and sphenopalatine fossae, inferior orbital fissure and nasolacrimal duct involvement, premaxillary thickening, retro-antral and orbital stranding, and infratemporal muscle oedema. It was determined that the combined occurrence of any three out of nine markers was 91.5% sensitive and 95.9% specific for diagnosis of AIFS (p < 0.005).

Early, accurate detection of AIFS in predisposed individuals is possible with identification of soft-tissue markers on NECT, enabling early intervention.

Being the aggressive disease that it is, AIFS may be managed early if the index of suspicion is held high via CT imaging; which our diagnostic checklist aims at enabling.