Radiological Imaging Findings of Rhino-Orbito-Cerebral Mucormycosis in COVID and Post-COVID Patients - A Descriptive Study of 200 Patients

Abstract

BACKGROUND Rhino-orbito-cerebral mucormycosis (ROCM) is a life-threatening infection caused by saprophytic fungi. The purpose of this study was to describe common radiographic patterns that may be useful in predicting the diagnosis and assessing the extent of involvement of rhino-orbito-cerebral mucormycosis in Covid and post Covid patients. METHODS The case records of patients with rhino-orbito-cerebral mucormycosis were reviewed. This included 200 patients of which 122 were males and 78 females, with a minimum age of 22 to a maximum of 80 years old. Computed tomography (CT) and / or magnetic resonance imaging (MRI) images were retrieved from the picture archiving and communication system (PACS) and analysed. Statistical analysis was performed using descriptive statistics. RESULTS All the patients showed sinusitis and ophthalmological symptoms. CT and MR imaging showed predominant involvement of the maxillary (196, 98 %) and ethmoid (194, 97 %) sinuses. Involvement of the orbit (186, 93 %) and face (114, 57 %) preceded involvement of the pterygopalatine fossa (90, 45 %) and brain (52, 26 %). CT showed minimally enhancing hypodense soft tissue thickening as the predominant finding in involved areas, while MRI showed T2 isointense to mildly hypointense soft tissue thickening and heterogeneous post-contrast enhancement as the main finding. In patients with extra sinus extension, bone erosion was seen in 80 patients (40 %) but few (20, 10 %) of the patients showed extension across grossly intact appearing bones. CONCLUSIONS In the context of Covid-19 with immunosuppression, a pattern of the nasal cavity, maxillary sinus, ethmoid cells, and orbit inflammatory lesions should prompt the diagnosis of mucormycosis. Progressive and rapid involvement of the cavernous sinus, vascular structures and intracranial contents can occur. Multiplanar magnetic resonance imaging and computed tomography show anatomic involvement, helping in surgery planning. KEY WORDS Rhino-Orbito-Cerebral mucormycosis, Imaging Findings, MRI, Neuroradiology