Dynamic Contrast-Enhanced MRI Phenotyping of Pituitary Microadenomas and Macroadenomas: Integrated Correlation With Prolactin Profile and Clinical Presentation

Abstract

Pituitary adenomas are common sellar lesions with heterogeneous radiological, hormonal, and clinical presentations. This study evaluated the role of dynamic contrast-enhanced MRI (DCE-MRI) in discriminating pituitary microadenomas from macroadenomas and correlating imaging findings with serum prolactin levels and clinical manifestations. A prospective cross-sectional study included 100 patients with suspected pituitary lesions who underwent conventional T1-weighted, T2-weighted, DCE-MRI, delayed post-contrast MRI, and serum prolactin assessment. MRI detected abnormalities in 75% of cases (p<0.001), including microadenomas in 44%, macroadenomas in 31%, and non-adenomatous findings in 25%. Microadenomas predominated in females, with mild prolactin elevation in 100%, irregular menstrual cycles in 58.9%, and mild galactorrhea in 58.9%. Macroadenomas were more common in males, with severe prolactin elevation in 72.2% and severe galactorrhea in 48.1%. Non-adenomatous cases showed normal prolactin and absence of galactorrhea in 100%. Pre-contrast T1-WI showed the highest signal score in non-adenomas (mean=3.0) and the lowest in macroadenomas (mean=1.0; p<0.001). DCE-MRI demonstrated heterogeneous enhancement as the most frequent pattern (31%), followed by hypo enhancement (22%) and homogeneous early enhancement (15%). Integrating DCE-MRI with prolactin profile and clinical presentation may improve characterization and diagnostic stratification of pituitary adenoma subtypes.