Quantitative susceptibility mapping of the human carotid artery: Assessing sensitivity to elastin and collagen ex...

The aim is to establish the relationship between carotid susceptibility and microstructural components in diseased carotid arteries.

Excised cadaveric carotid arteries (n = 5) were scanned using high-resolution QSM at 7 Tesla. After ex vivo imaging, all samples were brought to histology and stained for elastin, collagen, cells, and calcium. An image registration pipeline was used in combination with semi-quantitative, regional histology analysis to evaluate relationships between MRI and microstructural components.

Weak, non-significant (p > 0.05) correlations were found between all components and regional magnitude and R₂* measurements. A significant, moderate negative correlation between the elastin fraction and regional magnetic susceptibility, r_elastin = -0.63 (p < 0.0001) was found, as well as a significant, moderate negative correlation between collagen and regional magnetic susceptibility, r_collagen = -0.59 (p < 0.0001).

Tissue magnetic susceptibility in diseased human carotid arteries was shown to be significantly correlated with the dominant microstructural components of pathological human cadaver samples-elastin and collagen. Knowing that elastin and collagen are disrupted in vascular disease progression, QSM offers clinically translatable potential for novel disease biomarkers.