Molecular Imaging of Inflammation in a Mouse Model of Atherosclerosis Using a Zirconium-89-Labeled Probe

Beyond clinical atherosclerosis imaging of vessel stenosis and plaque morphology, early detection of inflamed atherosclerotic lesions by molecular imaging could improve risk assessment and clinical management in high-risk patients. To identify inflamed atherosclerotic lesions by molecular imaging in vivo, we studied the specificity of our radiotracer based on maleylated (Mal) human serum albumin (HSA), which targets key features of unstable atherosclerotic lesions. Mal-HSA was radiolabeled with a positron-emitting metal ion, zirconium-89 ( Zr ). The targeting potential of this probe was compared with unspecific Zr-HSA and F-FDG in an experimental model of atherosclerosis ( mice, n=22), and compared with wild-type (WT) mice (C57BL/6J, n=21) as controls. PET/MRI, gamma counter measurements, and autoradiography showed the accumulation of Zr-Mal-HSA in the atherosclerotic lesions of mice. The maximum standardized uptake values (SUV ) for Zr-Mal-HSA at 16 and 20 weeks were 26% and 20% higher (