Dynamic Contrast-Enhanced MRI in Abdominal Aortic Aneurysms as a Potential Marker for Disease Progression

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Radiology

Background:

• Abdominal aortic aneurysms (AAAs) pose a rupture risk, even below surgical thresholds.
• Aortic wall microvasculature is linked to elastin and rupture sites, but its role in AAA progression is unclear.

Purpose of the Study:

• To determine if dynamic contrast-enhanced (DCE) MRI of AAAs correlates with maximum diameter (Dmax) or growth rate.
• To investigate the relationship between aortic wall microvasculature and AAA progression.

Main Methods:

• Prospective study of 27 male patients with infrarenal AAAs using 3-T DCE MRI.
• Analysis of contrast uptake parameters (slope, AUC, Ktrans) in AAA wall voxels.
• Correlation of DCE MRI metrics with Dmax and growth rate, assessed using Pearson correlation and linear mixed effects models.

Main Results:

• DCE MRI measurements showed significant correlation with each other and differed between AAA quadrants.
• No significant association was found between DCE MRI metrics and AAA maximum diameter (Dmax).
• The 1-minute slope and 4-minute AUC of contrast enhancement were significantly associated with AAA growth rate, independent of Dmax.

Conclusions:

• Contrast enhancement in lateral AAA aspects may indicate increased microvascular activity.
• DCE MRI's 1-minute slope and 4-minute AUC are potential biomarkers for recent AAA growth, irrespective of Dmax.
• These findings may improve monitoring and risk stratification for abdominal aortic aneurysms.