Magnetic Resonance Imaging-Based Radiological and Morphologic Analysis of the Pituitary Gland in the Setting of Non-Pituitary Intracranial Space-Occupying Lesions

Background and objective The pituitary gland is a small gland located in the pituitary fossa. Significant variations in pituitary gland size and shape exist across different age groups and genders. This variability can create uncertainty, making it challenging for radiologists to determine whether a certain size falls within a normal range. This study aimed to analyze the morphometric features of the pituitary gland in relation to age and sex among individuals without apparent pituitary disease or any medical condition affecting the pituitary gland. Methodology This retrospective observational study was conducted at the Department of Radiology, Punjab Institute of Neurosciences, Lahore, Pakistan. Clinical information and magnetic resonance imaging (MRI) reports of 502 consecutive eligible patients were retrieved between January 1, 2022, and December 31, 2024. Morphometric measurements of the pituitary gland in relation to age and sex were obtained from individuals with non-pituitary space-occupying lesions (SOLs) using T1-weighted midsagittal and T2-weighted coronal brain MRI images. The Mann-Whitney U test was performed to compare morphometric parameters between male and female participants, whereas the Kruskal-Wallis test was performed to assess differences across age groups. Post hoc pairwise comparisons with Bonferroni correction were subsequently performed to evaluate significant differences between age groups. Results With a cohort size of 502 and a slight male predominance, with 269 (53.58%) male participants, the majority of participants were in the 21-30-year age group, comprising 98 (19.5%) participants. A flat superior surface was observed in 245 (48.8%) participants. The mean pituitary height was 5.48 ± 1.49 mm and 5.32 ± 1.43 mm in female and male participants, respectively. The mean length was 9.45 ± 1.72 mm and 9.10 ± 1.60 mm in male and female participants, respectively. The mean pituitary width was 12.13 ± 4.7 mm and 11.8 ± 2.45 mm in male and female participants, respectively. The mean volume was 315.17 ± 137.11 mm³ and 314.89 ± 140.48 mm³ in male and female participants, respectively. Mean pituitary height was higher in female participants, whereas length, width, and volume were higher in male participants. However, only the difference in length was statistically significant (U = 27525.00, Z = -2.355, p = 0.019). The length of the gland showed a statistically significant linear increase across the age groups, from younger to older participants. Height, width, and volume displayed a peak-and-decline pattern, reaching a significant peak at age 21-30 years, then declining in older age. Conclusion The flat superior surface was the most commonly noted shape of the pituitary gland. The volume, width, and height of the pituitary gland increased gradually with age and declined in older adults. However, pituitary gland length increased with age, without any notable fluctuations in measurements across the age groups.