Purpose: To present a new MR classification for pituitary adenomas, a grading system named SIPAP.
Material and methods: SIPAP is an acronym for the 5 juxtasellar directions of tumour extension to or penetration into adjacent structures of the sella region, using a 6-figure number for each adenoma. This retrospective study was based on 87 mid-field MR examination of 56 patients with biochemically or surgically confirmed pituitary adenomas. Sagittal T1-weighted SE and coronal T1-weighted 3D FFE sequences before and after i.v. contrast administration were performed.
Results: The SIPAP classification was well adapted to the material. All tumours except one postoperative remnant could be classified in the grading system. The classification was useful before and after treatment, for follow-up over a longer period, and for comparing adenomas with different hormonal activity with reference to patient age and sex.
Conclusion: The SIPAP classification together with tumour size is an optimal method for the registration of pituitary adenomas.