Uptake of (68)gallium in atherosclerotic plaques in LDLR(-/-)ApoB(100/100) mice

作者：Silvola Johanna M U^*; Laitinen Iina; Sipila Henri J; Laine V Jukka O; Leppanen Pia; Yla Herttuala Seppo; Knuuti Juhani; Roivainen Anne

来源：EJNMMI Research, 2011, 1: 14.

DOI：10.1186/2191-219X-1-14

• atherosclerosis
• plaque
• autoradiography
• gallium-68
• PET

Background: Atherosclerosis is a chronic inflammatory disease of artery wall characterized by infiltration of monocytes into subendothelial space and their differentiation into macrophages. Since rupture-prone plaques commonly contain high amounts of activated macrophages, imaging of the macrophage content may provide a useful tool for the evaluation of plaque vulnerability. The purpose of this study was to explore the uptake of (68)gallium (Ga-68) in atherosclerotic plaques in mice.
Methods: Uptake of ionic Ga-68 was investigated in atherosclerotic LDLR(-/-)ApoB(100/100) and C57BL/6N control mice at 3 h after injection. The ex vivo biodistribution of the Ga-68 was assessed and autoradiography of aortic cryosections was defined. In vivo imaging of Ga-68 was performed using a small animal positron emission tomography PET/CT scanner.
Results: Our results revealed that the uptake of Ga-68-radioactivity was higher in atherosclerotic plaques than in healthy vessel wall (ratio 1.8 +/- 0.2, p = 0.0002) and adventitia (ratio 1.3 +/- 0.2, p = 0.0011). The autoradiography signal co-localized with macrophages prominently as demonstrated by Mac-3 staining. In both mice strains, the highest level of radioactivity was found in the blood.
Conclusions: We observed a moderate but significantly elevated Ga-68-radioactivity uptake in the aortic plaques of atherosclerotic mice, especially at the sites rich in macrophages. While the uptake of Ga-68 was promising in this animal model, the slow blood clearance may limit the usability of Ga-68 as a PET tracer for clinical imaging of atherosclerotic plaques.

• 出版日期2011