Quantitative 3-Dimensional Characterization of Aortic and Carotid Artery Tortuosity in Mucopolysaccharidosis Type IVa: An Exploratory Comparative Imaging Study

Background/Objectives: Vascular involvement has been described in mucopolysaccharidosis type IVa (MPS IVa), but the morphology of the aorta and carotid arteries has not been comprehensively characterized. This study aimed to quantitatively assess aortic and carotid artery tortuosity and kinking using contrast-enhanced three-dimensional (3D) magnetic resonance (MR) angiography. Methods: In this retrospective exploratory comparative imaging study, six patients with confirmed MPS IVa underwent clinically indicated 3D MR angiography of the aorta and supraaortic vessels; two were excluded due to motion artifacts, leaving four patients for analysis. Two radiologists independently assessed vascular kinking and tortuosity. For comparison, 12 age- and sex-matched polytrauma patients without documented vascular abnormalities were retrospectively evaluated using computed tomography angiography. Results: All four patients with MPS IVa showed multiple kinking sites of the descending aorta and increased tortuosity of the common and internal carotid arteries. Aortic tortuosity indices ranged from 2.01 to 2.68. Carotid tortuosity indices were also increased, particularly in the internal carotid arteries. Compared with controls, all assessed tortuosity indices were consistently higher in patients with MPS IVa (exploratory p = 0.001). Despite multiple aortic kinking sites, no marked anatomical luminal narrowing was observed. Conclusions: This exploratory study provides quantitative evidence of differences in aortic and carotid geometry between a small, highly selected MPS IVa cohort and external imaging controls. Larger studies using harmonized imaging protocols and longitudinal follow-up are needed to assess prevalence, disease-specific causation and clinical significance of these findings.