Postoperative Pituitary MRI Findings in Acromegaly: A Pictorial Review

Abstract

Acromegaly is almost always caused by a growth hormone-secreting pituitary adenoma, and long-term cure depends on complete surgical resection and accurate detection of residual or recurrent disease on surveillance imaging. This pictorial review focuses on the 3–6-month postoperative interval, when routine surveillance MRI is commonly performed and dynamic contrast-enhanced pituitary imaging can be correlated with IGF-1 and GH trends. We first reviewnormal pituitary anatomy and imaging characteristics, and the typical location and signal characteristics of somatotroph adenomas, as a baseline for postoperative interpretation. Using representative cases of surgically treated acromegaly, we then illustrate the key postoperative MRI appearances on high-resolution T1- and T2-weighted and dynamic contrast-enhanced sequences. Benign patterns include non-enhancing T1-hyperintense packing material, thin rim or septal enhancement around thesurgical cavity, sheet-like floor-based granulation tissue, and simple stalk deviation with nromal rangecaliber, often seen in biochemically cured patients. High-risk imaging patterns comprise nodular or thick enhancing tissue in the resection bed, new or progressive cavernous sinus soft tissue, stalk thickening with avid enhancement, and a spectrum of cavernous carotid abnormalities. For each pattern, we emphasize prevalence, typical signal and enhancement characteristics, and reported correlations with biochemical remission or persistence of disease. Finally, we propose a simple flowchart that integrates biochemical status with these reproducible imaging findings to stratify patients into expected postoperative change, probable residual/recurrent adenoma, vascular complication, or indeterminate category. This pattern-based biochemical–radiologic framework is intended to help radiologists and endocrinologists interpret mid-term postoperative pituitary MRI in acromegaly more confidently and consistently.