Supplementary Material for: The relationship between pineal gland and choroid plexus calcifications. Potential link for an intracranial calcification phenotype?

Introduction: Little is known about the association between the most common brain structures presenting with calcium deposits, the pineal gland and the choroid plexus. This study aims to assess whether the extent of pineal gland calcifications (PGC) and choroid plexus calcifications (PGC) are independent or correlate to each other.
Methods: The study included 1,009 individuals aged ≥40 years enrolled in a population-based cohort who received a head CT. Images were converted to the Neuroimaging Informatics Technology Initiative format, and whole brain segmentation was performed using SynthSeg. Voxels within the pineal gland region and the ventricular cavities with attenuation >50 HU were considered to contain a calcified component. Total voxel volumes within both regions were calculated for each participant. Linear regression models were fitted to assess the association between PGC and CPC volumes. Non-parametric locally weighted scatterplot smoothing regression was used to evaluate the relationship between these variables.
Results: PGC were associated with CPC (β: 0.018; 95% C.I.: 0.009 – 0.027), after adjusting for demographics. The Pearson correlation coefficient for this association was 0.1636 (p<0.001) while the Spearman pairwise rank correlation coefficient was 0.1647 (p<0.001).
Conclusions: PGC and CPC are significantly correlated, suggesting the existence of an intrinsic predisposition to facilitate calcium deposits in brain tissues.