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

Abdominal aortic aneurysms (AAAs) may rupture before reaching maximum diameter (D ) thresholds for repair. Aortic wall microvasculature has been associated with elastin content and rupture sites in specimens, but its relation to progression is unknown. To investigate whether dynamic contrast-enhanced (DCE) MRI of AAA is associated with D or growth. Prospective. A total of 27 male patients with infrarenal AAA (mean age ± standard deviation = 75 ± 5 years) under surveillance with DCE MRI and 2 years of prior follow-up intervals with computed tomography (CT) or MRI. A 3-T, dynamic three-dimensional (3D) fast gradient-echo stack-of-stars volumetric interpolated breath-hold examination (Star-VIBE). Wall voxels were manually segmented in two consecutive slices at the level of D . We measured slope to 1-minute and area under the curve (AUC) to 1 minute and 4 minutes of the signal intensity change postcontrast relative to that precontrast arrival, and, K , a measure of microvascular permeability, using the Patlak model. These were averaged over all wall voxels for association to D and growth rate, and, over left/right and anterior/posterior quadrants for testing circumferential homogeneity. D was measured orthogonal to the aortic centerline and growth rate was calculated by linear fit of D measurements. Pearson correlation and linear mixed effects models. A P value