Automated MRI-based brain volumetric analysis in women with polycystic ovary syndrome

Polycystic ovary syndrome is associated with complex endocrine and metabolic disturbances that may influence brain structure. This study aimed to evaluate global and regional brain volumes in women with polycystic ovary syndrome using automated magnetic resonance imaging–based volumetric analysis with age- and sex-adjusted normative percentiles, and to investigate their associations with hormonal and metabolic parameters. This retrospective observational study included 48 women with polycystic ovary syndrome who underwent brain magnetic resonance imaging. Automated volumetric analysis was performed on high-resolution three-dimensional T1-weighted images using Quantib® Brain automated volumetry software. Total brain volume, lobar volumes, hippocampal volumes, cerebellar volume, and cerebrospinal fluid volume were quantified and normalized to intracranial volume. Normative percentile values were used instead of a separate healthy control group. Volumetric measures were compared according to insulin resistance status and luteinizing hormone/follicle-stimulating hormone ratio, and multivariable regression analyses were performed to identify independent predictors of brain volume measures. Global and lobar brain volumes did not differ significantly according to insulin resistance, total testosterone, or dehydroepiandrosterone sulfate levels. Cerebrospinal fluid volume was higher in insulin-resistant individuals; however, this association did not remain significant after correction for multiple comparisons. In contrast, hippocampal volumes differed significantly according to the luteinizing hormone/follicle-stimulating hormone ratio. Women with an LH/FSH ratio ≥ 2 exhibited lower total hippocampal volume, predominantly driven by reduced left hippocampal volume (p = 0.009). Automated magnetic resonance imaging–based volumetric analysis demonstrated largely preserved global and lobar brain volumes in women with polycystic ovary syndrome. However, an elevated luteinizing hormone/follicle-stimulating hormone ratio was selectively associated with reduced hippocampal volume, suggesting region-specific neuroanatomical vulnerability potentially related to gonadotropin dysregulation.