A current perspective of pituitary adenoma MRI characteristics: a review

Abstract

Introduction: MR imaging is an essential and fundamental tool in the diagnosis, management, and follow-up of patients with pituitary adenomas (PAs). Recent advances have continued to enhance the usefulness of this imaging modality.

Areas covered: This article focuses on signal intensity patterns of PAs and associated clinical characteristics, vertical extension patterns, and cavernous sinus invasion with a special focus on the clinical implications that arise. A search using Medline and Google Scholar was conducted using different combinations of relevant keywords, giving preference to recent publications.

Expert opinion: A higher proportion of GH-secreting PAs are hypointense on T2 weighted images compared to other tumor subtypes. Hypointense tumors are generally smaller compared to hyperintense ones, and among the GH-secreting subgroup, a better response to somatostatin analogue treatment was noted together with an association for a densely granulated pattern. Nonfunctional PAs show a predilection to extend upwards while GH-secreting PAs and prolactinomas show a predominantly inferior extension growth pattern. Further studies to better understand the mechanisms responsible for this behavior are anticipated. Further development, refining and validation of predictive scoring systems for tumor behavior might be useful adjuncts in the management of patients with PAs.

Keywords: MRI; T2 signal intensity; cavernous sinus invasion; pituitary adenoma; vertical extension.