Evaluation of interpeduncular angle values according to age and gender by magnetic resonance imaging

Aim: This study aimed to establish normative, age- and sex-stratified reference values for the interpeduncular angle (IPA), pontomesencephalic angle (PMA), and pontomedullary angle using magnetic resonance imaging (MRI) in a healthy adult population. Material and Methods: This retrospective study included 290 healthy adult patients (124 males, 166 females; mean age: 43.1 ± 16.7 years) who underwent brain MRI between January 2018 and December 2020. IPA, PMA, and pontomedullary angles were measured on standardized axial and mid-sagittal T1-weighted spin-echo MRI sequences. The classification was as follows: 18–24 years (young adults), 25–33 years (adults), 34–48 years (early middle-aged), 49–64 years (middle-aged), ≥65 years (elderly). Results: The mean IPA was 75.5° ± 10.2, PMA was 57.0° ± 10.2, and pontomedullary angle was 133.8° ± 10.6. No significant differences in any angular measurements were observed between male and female (p > 0.05). However, a significant increase in IPA values was observed with advancing age (p