CT Imaging Features in Acute Invasive Fungal Rhinosinusitis- Recalling the Oblivion in the COVID Era

OBJECTIVE: Recent pandemic of COVID19 infection has witnessed a re-emergence of invasive fungal sinusitis especially of the Mucor species, which has been a rare entity in the pre covid era. Covid associated mucormycosis (CAM) is one of the dreaded and fatal complications which has surfaced up and early diagnosis is critical for management and survival .It is identified to affect both subset of patients, those with active COVID-19 infection and those who have recovered from the disease in the last 4-6 weeks. Imaging features suggestive of early invasion with supportive imaging examples and relevance of these findings in clinical decision making is presented. METHODS: This paper reviews the various imaging signs of early invasion in CAM A comprehensive checklist for clinically relevant and quick reporting is also presented. RESULTS: Emphysematous or ulcerative mucosal changes in the nasal cavity is an early imaging feature of CAM. Periantral soft tissue and soft tissue within the pterygopalatine fossa are important imaging signs to indicate extrasinus invasion. Disease within pterygopalatine fossa may lead to multidirectional spread and is an important check site. These findings are seen even in absence of bony erosions owing to the neurovascular spread of disease. Intra orbital and intracranial extensions were found to be fairly common and must be sought for. CONCLUSION: The knowledge of early subtle signs of CAM on imaging can aid in prompt diagnosis of this fatal entity in the pertinent clinical setting. Imaging signs of spread of disease and delineation of its extent as inferred from CT imaging aids in prognosis and appropriate surgical management.