A 16-Year Study on Incidence and Progression of Diseased Sphenoethmoidal (Onodi) Cell

Figure 1

An example of bilateral sphenoethmoidal cells that meet the criteria of more than or equal to 5 mm posterior or superolateral extension. R: right sphenoethmoidal cell; L: left sphenoethmoidal cell; S: sphenoid sinus; arrow: optic canal.