Spectrum of Orbital Cellulitis on Magnetic Resonance Imaging

Introduction Orbital infection is an ophthalmological emergency as it can lead to blindness and intracranial spread. Imaging is needed to determine the extent of the infection, to localize an abscess, and for surgical planning. The role of magnetic resonance imaging (MRI) is well established in the evaluation of orbital pathologies, including orbital cellulitis and abscess, mainly due to its ability to evaluate early intracranial involvement. The objective of the study was to highlight the spectrum of MR imaging findings and the pattern of spread in fifteen patients with orbital cellulitis. Methods A prospective study was conducted in a tertiary care hospital. Fifteen patients of all age groups, of either sex, presenting with clinical findings suggestive of orbital cellulitis, referred for MRI of orbits, were included in the study. Written informed consent was obtained prior to the study. Patients' demographic data such as age and gender, associated co-morbidities, complications, and the pattern of spread of disease on MRI were recorded and evaluated. Descriptive statistics were used. Results Orbital/periorbital abscess was found to be the most common complication of orbital cellulitis (eight cases, 53.3%), followed by optic neuritis/perineuritis (four cases, 26.67%), intracranial involvement (four cases, 26.67%), dacryoadenitis (three cases, 20%) and cavernous sinus thrombophlebitis (three cases, 20%). Seven cases (46.67%) had right orbital involvement. Sinusitis was found to be the most common predisposing factor. Amongst the cases associated with sinusitis, the commonest inflamed paranasal sinus was found to be the ethmoid sinus (twelve cases). Amongst the fifteen cases of orbital/periorbital cellulitis, there were only two cases of isolated preseptal cellulitis (13.33%), five cases of postseptal cellulitis (33.33%) and eight cases of both preseptal and postseptal orbital cellulitis (53.33%). Conclusion MRI is the imaging modality of choice in the evaluation of orbital cellulitis because of its superior soft tissue and contrast resolution. It is vital to evaluate the extent of the orbital infection, underlying paranasal sinus involvement, as well as detect complications of orbital cellulitis, especially intracranial spread.