MRI Based Analysis of Pituitary Gland Dimensions: Age and Sex Related Variation. A Hospital Based Study

Abstract

Introduction: The hypophysis cerebri (pituitary gland) is a small but pivotal endocrine organ that regulates the secretion of multiple peripheral endocrine glands. Accurate knowledge of its normal dimensions is essential for distinguishing physiological from pathological changes on neuroimaging.

Aims: To establish normative reference data on pituitary gland dimensions and to evaluate the influence of age and sex on these measurements.

Methods: A hospital based cross sectional study was conducted on 200 subjects (76 males, 124 females) aged 11 years and above, referred for brain Magnetic Resonance Imaging at the Department of Radiology, Nepalgunj Medical College. Anteroposterior diameter, transverse diameter, height, and volume of pituitary gland were measured from standardized magnetic resonance imaging sequences.

Results: The overall mean anterioposterior diameter, transverse diameter, height, and volume were 10.01±1.60 mm, 13.33±2.34 mm, 6.47±1.53 mm, and 461.11±203.35 mm³, respectively. Females demonstrated greater mean values across all parameters compared to males (AP: 10.16±1.42 vs 9.76±1.84 mm; height: 6.56±1.38 vs 6.33±1.74 mm; volume: 471.75±145.56 vs 443.76±272.91 mm³). Pituitary height and volume were greatest in the 11–20 years age group, while maximum anterioposterior and transverse dimensions were observed in the 41–50 and 21–30 years groups, respectively. One way ANOVA revealed statistically significant variation with age for anterioposterior diameter (p=0.009) and height (p=0.024).

Conclusion: Pituitary gland dimensions exhibit significant age   and sex related variation. Normative reference values were established: overall mean anterioposterior diameter 10.01±1.60 mm, transverse diameter 13.33±2.34 mm, height 6.47±1.53 mm, and volume 461.11±203.35 mm³. Females consistently demonstrate larger dimensions, with peak gland size observed during the pubertal decade. These normative data may serve as a useful radiological reference for differentiating physiological from pathological pituitary changes.