Age-Related Pituitary Volumes in Prepubertal Children with Normal Endocrine Function: Volumetric Magnetic Resonance Data

Background: Evaluation of the size of the pituitary gland on magnetic resonance imaging (MRI) may be difficult, considering the wide variation in normal gland morphology. Given the paucity of age-related biometric data, our purpose was to obtain standard normal reference values for pituitary volumes in prepubertal children using three-dimensional MRI data. Methods: Children under the age of 10 yr undergoing brain MRI for seizures or idiopathic developmental delay and who had no endocrine abnormality were recruited prospectively over 2 yr. All MRI studies included a three-dimensional sequence. Only subjects with normal studies were included. One hundred thirty-nine children were eligible (mean age, 5.2 yr). Direct pituitary volumes were measured from contiguous 1-mm thick reconstructed coronal and sagittal images. Estimated pituitary volumes were calculated using pituitary height, width, and length. Results: Volumes obtained from reconstructions in either plane were essentially identical. There was a linear increase in log-transformed pituitary volume with age, but relatively weak correlations with height or body mass index. There was no gender difference and only weak correlations between pituitary height and pituitary volume and between estimated pituitary volume calculation and measured pituitary volume. We provide age-related reference ranges for pituitary volumes in graphical and tabular forms.