Clinical Radiograph of The Week: Vol1,No7

The following case was presented in the recent (vol1no7) issue of otorhinolaryngology news:
A 30-year old female was referred from the neurology clinic where she had presented with insomnia of 3 months duration following a near-fatal accident involving a car she was travelling in. She sustained no injury during the near-fatal accident. Examination was essentially normal. MRI brain revealed the feature (red arrow) on this picture. You way want to see the axial view of contrast-enhanced MRI

Differential diagnosis here include (1) isolated ethmoidal polyp (incidental finding) and (2) mucocoele of ethmoidal sinus.