[Radiological surveillance of operated ethmoidal cancers. Practical points]

Radiological follow-up of ethmoidal neoplasms is not clearly established in terms of imaging modalities (CT, MRI) or periodicity. This paper, based on 4 typical cases, tries to describe the main imaging features of this radiological follow-up. Initial CT 3 to 6 months after surgery is essential, being the reference examination. It can show postoperative bone changes. During follow-up, a CT scanner every 6 months seems sufficient. For the image interpretation, a comparison with the two previous CT is mandatory. Any bone destruction must be considered as suspicious, even if very small. MRI should be performed in case of sphenoidal opacity, in order to differentiate between tumor recurrence and retentional fluid. MRI is also necessary and useful when the tumor presents an intradural or intracranial extension.