Revisiting the Anatomy of the Paranasal Sinuses and their Radiological Correlations in Sinusitis

Sinusitis is among the most frequently encountered conditions in primary care, otolaryngology, and radiology practice. Despite its clinical prevalence, accurate diagnosis and effective management depend on a sound understanding of paranasal sinus anatomy, developmental variation, and imaging appearances. This review revisits the gross and radiological anatomy of the paranasal sinuses, with a particular focus on embryological development, drainage pathways, and anatomical relationships that influence disease spread and surgical decision-making. Imaging plays a central role in this context. High-resolution computed tomography and magnetic resonance imaging are invaluable in evaluating sinusitis, delineating anatomical variants, and identifying complications. Common variations, including concha bullosa, deviated nasal septum, Haller cells, Onodi cells, sinus hypoplasia, and pneumatosinus dilatans, are discussed with reference to their effects on sinus ventilation and their contribution to recurrent or chronic disease. The typical radiological appearances of acute and chronic rhinosinusitis, as well as variations, are also outlined. By integrating anatomical principles with radiological findings, this article highlights the value of imaging not only in confirming the diagnosis of sinusitis but also in identifying predisposing factors, guiding endoscopic intervention, and minimising the risk of serious complications. An anatomical–radiological approach remains central to contemporary, evidence-based management of sinonasal disease.