COVID-Associated Sinonasal Mucormycosis: Radiological Pathological Correlation and Prognostic Value of MR Imaging

Purpose:Our aim was to assess the sinonasal magnetic resonance imaging (MRI) features of acute invasive fungal rhinosinusitis (AIFRS) in coronavirus disease (COVID)-associated mucormycosis (CAM) and to correlate these with histopathology and patient outcome in terms of duration of hospital stay and survival at 10 weeks. Methods:Twenty patients with histopathologically confirmed sinonasal CAM underwent MRI (including postcontrast T1-weighted and diffusion-weighted imaging). Histopathological findings (presence of coagulative necrosis, granulomatous reaction, and fungal burden) were recorded and all patients were followed up at 6 and 10 weeks. Statistical analysis was done using chi-square test and Fischer's exact test. Results:Enhancement patterns seen in our subjects included homogeneous, heterogeneous, and lack of contrast enhancement (LOC), with LOC being the most common (65%). Diffusion restriction was found in 90% patients. Statistically significant correlation was found between LOC pattern and presence of coagulative necrosis ( p -value = 0.007), extent of fungal hyphae ( p -value = 0.047), and duration of hospital stay ( p -value = 0.004). Restricted diffusion was also seen to correlate with a high fungal load ( p -value = 0.007). Conclusion:Our study describes the MRI findings of AIFRS in CAM and highlights the imaging features which may be surrogate markers for coagulative necrosis and fungal burden.