MRI appearances of the sphenoid sinus at the late follow‐up of trans‐sphenoidal surgery for pituitary macroadenoma

Abstract

We aimed to demonstrate the appearances of the sphenoid sinus on MRI performed later than 2 years post- transsphenoidal surgery (TSS). We retrospectively reviewed 47 patients in whom follow-up MRI scans had been performed at least 2 years post-TSS. We specifically reviewed the clinical and imaging of those patients in whom the sphenoid sinus was filled with signal abnormality or masses were present arising from the sinus roof and classified them as tumour or indeterminate abnormalities on imaging criteria. We documented other clinicoradiological details. Twelve of 47 patients demonstrated sphenoid sinus filling or sinus roof masses and in six of 12 patients it was possible to classify them as tumourous using imaging and clinical criteria. The indeterminate and non-tumourous sphenoid sinus abnormalities most frequently had a T1-weighted signal similar to subsellar tumour and displayed rim enhancement and thus could not be reliably distinguished from tumourous abnormality on the basis of signal or enhancement characteristics. The presence of a well-defined surgical defect in the sella floor was associated with resolution of abnormality on MRI follow-up. We concluded MRI findings of sphenoid sinus filling or sinus roof masses are present in approximately 26% of scans performed longer than 2 years post-TSS. Half of these are of indeterminate origin and follow-up is required to discriminate tumour from non- tumour with certainty. A well-defined surgical defect in the sella floor is, however, suggestive of a non-tumourous abnormality.

Diagnostic Imaging of the Pituitary and Parasellar Region

“…As mentioned above, the transsphenoidal approach is currently the method of choice in treatment of most of pituitary tumors. There are characteristic changes inside the sphenoid sinus after the surgery (Connor & Deasy, 2002). MRI findings of sphenoid sinus filling (opacification) are present in approximately 37% of examinations performed more than 12 months after transsphenoidal surgery.…”

Are T2-weighted images more useful than T1-weighted contrast-enhanced images in assessment of postoperative sella and parasellar region?

“…T2-weighted unenhanced images are also performed sometimes, but most authors have reported postoperative studies of the sellar region using only T1-weighted images [18–20]. There are only a few papers concerning applications of T2-weighted sequences in imaging of the postoperative sella [21–23]. Nakasu et al found that T2-weighted imaging could be a reliable and sufficient method to assess the sella in patients after pituitary surgery [21].…”

Factors influencing the outcome of microsurgical transsphenoidal surgery for pituitary adenomas: A study on 184 patients

“…Often, they can be detected in serial MRI scans. 45,46 Therefore, the outcome of surgery regarding the control of the disease should only be based on biochemical results using the most current criteria for remission.…”