Mapping individual variability in the pituitary gland: A new volumetric atlas

The pituitary gland plays a fundamental role in regulating key physiological processes through complex hormonal interactions. However, its inherent anatomical variability across individuals has posed challenges for comprehensive volume assessments. This study addresses this gap by constructing a novel, standardized volumetric atlas of the pituitary gland in young females. Utilizing high-resolution MRI scans of 26 healthy subjects, we manually segmented the anterior and posterior pituitary lobes. A three-step spatial normalization procedure, incorporating a cost function-masking approach, optimized the anatomical representation of the gland. This methodology yielded probabilistic atlases and maximum probability maps for both lobes, which were subsequently co-registered to individual subjects’ data for validation. Manual measurements revealed a mean total pituitary volume of 705±88 mm³, further subdivided into an anterior lobe volume of 614±82 mm³ and a posterior lobe volume of 91±20 mm³. Notably, the discrepancy between manual and atlas-based volume estimations remained minimal at 1.3%. The constructed global pituitary atlas demonstrated strong concordance with manual delineations, achieving 80% (±9%) overlap as measured by the DICE index. Similar overlap was observed for the anterior and posterior pituitary atlases. This novel, standardized volumetric atlas represents a significant step forward in understanding individual variability within the pituitary gland. By enabling efficient and accurate assessment of pituitary volumes in large datasets, it provides a valuable resource for future research. Importantly, its potential applications extend beyond anatomical characterization, paving the way for guiding the development of personalized medicine approaches and targeted therapeutic interventions in various health conditions.