In-Vivo Molecular Imaging of Abdominal Aortic Aneurysm

Dynamic PET scan and corresponding computed tomography (CT) images were obtained using Inveon MM PET/CT (Siemens, Malvern, PA) at 45–60 min after a tail vein injection of ⁶⁴Cu-DOTA-ECL1i (11.1 MBq per rat) to minimize the effect of blood retention on AAA uptake. To localize tracer uptake, a CT contrast agent (1.0 mL, eXIA 160XL, Binitio, Canada) was administrated via tail vein after PET imaging. Contrast-enhanced CT (Bin of 2, 90 mm axial FOV, 60kV, 500μA, 500ms exposure time, 10 ms settle time, no magnification, pixel size: 80–100μm) was performed. The organ uptake was calculated as standardized uptake value (SUV) in three-dimensional regions of interest (ROIs) from PET images without correction for partial volume effect using Inveon Research Workplace software (Siemens).^{33 (link)} Competitive PET blocking studies were performed in the AAA rat model with co-injection of non-radiolabeled ECL1i and ⁶⁴Cu-DOTA-ECL1i (ECL1i:⁶⁴Cu-DOTA-ECL1i molar ratio = 500:1), followed by a 45–60 minute dynamic scan. Dynamic (0–90 min)¹⁸F-FDG (41.1 MBq per rat) PET was also performed in AAA rats at day 7 PEE.