MRI-derived proximal humeral cortical bone thickness as an opportunistic skeletal imaging parameter in acromegaly

To evaluate the relationship between MRI-derived proximal humeral cortical bone thickness and dual-energy X-ray absorptiometry (DXA)-derived bone mineral density (BMD) parameters in patients with acromegaly.

This retrospective study included 22 patients with acromegaly and 20 age- and sex-matched controls. Proximal humeral cortical bone thickness (CBTavg) was measured on coronal T1-weighted MRI images as the mean of four standardized cortical measurements. Lumbar spine DXA T-scores were recorded in the acromegaly cohort. Group comparisons, Spearman correlation analyses, and exploratory receiver operating characteristic (ROC) analysis were performed.

Mean CBTavg did not differ significantly between patients with acromegaly and controls (5.86 ± 1.83 mm vs 6.38 ± 1.33 mm, P = 0.294). Within the acromegaly cohort, CBTavg demonstrated a strong positive correlation with lumbar DXA T-scores (ρ = 0.906, p < 0.001). No significant associations were observed between CBTavg and disease duration or body mass index. Patients with active disease demonstrated lower mean CBTavg values compared with those in remission; however, this difference was not statistically significant. Exploratory ROC analysis demonstrated discriminative performance of CBTavg for identifying low BMD (AUC = 0.946).

MRI-derived proximal humeral cortical thickness is associated with DXA-derived BMD parameters in acromegaly and may provide opportunistic structural information from routine MRI examinations that include the proximal humerus. However, CBTavg did not significantly differ between patients with acromegaly and healthy controls and therefore should not be interpreted as a disease-specific skeletal biomarker.