Magnetic Resonance Imaging in Coronavirus Disease - 2019 Associated Rhino-Orbital-Cerebral Mucormycosis (CA-ROCM) - Imaging analysis of 50 consecutive patients.

Background and purpose Rhino-orbital-cerebral mucormycosis has emerged as a major opportunistic infection in patients with COVID-19. High clinical suspicion and prompt imaging are crucial for early diagnosis and management. Our study evaluates imaging characteristics of patients with COVID-19 associated Rhino-orbital-cerebral Mucormycosis (CA-ROCM) in a tertiary care hospital in India. Materials and methods A retrospective analysis of clinical and imaging data of patients with CA-ROCM who presented between December 2020 to June 2021 was performed. All patients had microbiologically or histologically proven sino-nasal mucormycosis along with documented SARS-CoV-2 positive RT-PCR test and/or classical lung imaging features of COVID-19 infection. The extent of sinus involvement, bony erosions, extra-sinus soft tissue extension, orbital-intracranial invasion, perineural spread, and vascular complications were assessed. Results Fifty patients were included for the final analysis. Diabetes was the most common associated comorbidity. Seven patients presented with stage I disease, 18 patients with stage II, and 25 patients with stage III disease. The stage of disease showed a positive statistical correlation with HbA1c levels using Pearson's correlation. The common imaging features were "Black turbinate sign" and nonenhancing sino-nasal mucosa (82%), orbital involvement (76%), and diffusion restriction in the optic nerve (24%). Intracranial involvement was seen as perineural extension into the brain (42%), cerebritis (30%), and internal carotid artery involvement (16%). Conclusions CA-ROCM is an acute invasive fungal sinusitis with an aggressive clinical course. Black-turbinate sign and peri-antral soft tissue infiltration are early features, whereas extra-nasal tissue infarction, optic nerve diffusion restriction, and vascular invasion are seen with advanced disease.