Comparison of 99mTc-annexin A5 with 18F-FDG for the detection of atherosclerosis in ApoE−/− mice
- First Online:
- Cite this article as:
- Zhao, Y., Kuge, Y., Zhao, S. et al. Eur J Nucl Med Mol Imaging (2007) 34: 1747. doi:10.1007/s00259-007-0433-2
- 193 Downloads
99mTc-annexin A5, a marker of ongoing apoptosis, and 18F-FDG, a marker of the increased metabolism of inflammatory cells, are supposed to be useful in the detection of metabolically active atheroma. This study reports a comparison of the intralesional distribution of these tracers in relation to lesion development in ApoE−/− mice.
Male ApoE−/− mice (n = 12–14/group) were maintained on a Western-type diet after the age of 5 weeks. At 25 weeks, 99mTc-annexin A5 or 18F-FDG was injected and the aortas were harvested for autoradiography (ARG) and Oil Red O staining. Regional radioactivity accumulation was compared in relation to the Oil Red O staining score (ranging from 0 to 3, a semiquantitative parameter for evaluating lesion development).
Both 99mTc-annexin A5 and 18F-FDG showed preferential uptake into atherosclerotic lesions, with higher uptake levels for 18F-FDG (mean, 56.07 %ID×kg/m2) than for 99mTc-annexin A5 (mean, 10.38 %ID×kg/m2). The regional uptake levels of each tracer correlated with the Oil Red O staining score (r = 0.65, p < 0.05 for 99mTc-annexin A5; r = 0.56, p < 0.05 for 18F-FDG). The uptake ratios of advanced lesions (score >0.5) to early lesions (score <0.5) were significantly higher for 99mTc-annexin A5 than for 18F-FDG (f = 4.73, p = 0.03).
Both 99mTc-annexin A5 and 18F-FDG accumulate in atherosclerotic lesions and correlate with the severity of each lesion. The higher absolute uptake levels of 18F-FDG may be advantageous for lesion detection, whereas the preferential uptake of 99mTc-annexin A5 in advanced lesions may be a useful indicator of late-stage lesions or vulnerable plaque transformation.