English SJ, Sastriques SE, Detering L, et al. - Given the important role of monocyte chemoattractant protein-1/CCR2 (chemokine receptor 2) axis in abdominal aortic aneurysm (AAA) pathogenesis, with its effects on disease progression and anatomic stability, researchers here examined a rodent model and human tissues for CCR2 expression, using a targeted positron emission tomography radiotracer (⁶⁴Cu-DOTA-ECL1i). Exposing the infrarenal, intraluminal aorta to PPE (porcine pancreatic elastase) under pressure resulted in induction of aneurysmal degeneration in Sprague-Dawley rats that resulted in generation of AAAs. A sham operative control was generated using heat-inactivated PPE. Administration of β-aminopropionitrile, a lysyl oxidase inhibitor, led to stimulation of rat AAA rupture. At 1 hour post tail vein injection of ⁶⁴Cu-DOTA-ECL1i, biodistribution in wild-type rats revealed fast renal clearance. At day 7 post-AAA induction, they observed nearly twice radiotracer uptake to that of sham-controls. Significantly decreased AAA uptake was observed with competitive CCR2 receptor blocking. Tracer uptake in AAAs that subsequently ruptured vs of nonruptured AAAs, was nearly twice. Outcomes support the promising value of CCR2 positron emission tomography as a new biomarker for the noninvasive assessment of AAA inflammation that may aid in associated rupture prediction.