A Novel Dual-Modality MRI/PET Probe
Gustafsson B, Louie A
University of California, Davis
A novel combined MRI/PET probe, targeted to atherosclerotic plaques, is reported. The probe is based on a maleylated bovine serum albumin with a conjugated 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ligand system, that can tether both paramagnetic Gd3+ and a positron emitter, e.g. 64Cu2+. Experiments in cultured cells demonstrate specific scavenger receptor A-mediated uptake of the probe by macrophages, present in early stages of atherosclerotic plaques, and show measurable contrast in MR image. Biodistribution studies in rat models show rapid clearance from the blood stream as well as clearance of the contrast agent by kidney and liver, which decreases to low levels by 24h.