Pituitary magnetic resonance imaging abnormalities and 1-year growth response in children with idiopathic growth hormone deficiency

Purpose: Brain magnetic resonance imaging (MRI) is used to assess anatomical abnormalities in children with idiopathic growth hormone deficiency (IGHD), but its prognostic relevance remains uncertain. We investigated whether structural abnormalities on brain MRI are associated with 1-year growth response to recombinant human growth hormone (rhGH) therapy in Korean children with IGHD.Methods: This multicenter retrospective study included 457 IGHD patients from the LG Growth Study registry who had baseline brain MRI and received rhGH therapy for ≥1 year. MRI findings were categorized as normal or as showing pituitary or extrapituitary abnormalities. Growth outcomes—change in height SDS (ΔHeight SDS) and height velocity—were compared across groups. Multivariable regression was performed to adjust for clinical variables.Results: Among 457 patients, 122 (26.7%) had structural abnormalities on brain MRI, while 335 (73.3%) had normal findings. In unadjusted analysis, those with abnormalities showed slightly lower ΔHeight SDS than those with normal brain MRI (p=0.028). However, subgroup differences were not significant when analyzed categorically. In multivariable regression, younger age at treatment (β=-0.050, p=0.004), higher baseline body mass index SDS (β=0.055, p=0.002), and greater rhGH dose (β=0.806, p=0.039) were significantly associated with greater ΔHeight SDS, while brain MRI abnormalities were not predictive of response.Conclusion: While brain MRI is an important diagnostic tool in IGHD for identifying anatomical abnormalities, our findings suggest that such abnormalities, particularly when mild or isolated, have limited utility in predicting short-term growth response to rhGH therapy.