Molecular Imaging of Endothelial Adhesion Molecules - Adhesion Molecules - page 64

that are excited at dif erent wavelengths, and multi-channel detectors capable
of receiving several signals at once, several biological processes were imaged
simultaneously. To investigate the biology of aortic valve degeneration, the
expression of VCAM-1, calcii cation, macrophage recruitment and protease
activity were simultaneously imaged using a panel of near-infrared l uorescence
imaging agents (Aikawa et al. 2007) (Fig. 5) .
Fig. 5 Multimodal imaging of early aortic valve disease. Multimodal: (A) Ex vivo MRI of the
mouse aortic arch and root. Negative signal enhancement (darkening) is seen at the areas of uptake
of VCAM-1-targeted nanoparticles. Dot ed line indicates the slice position of the short axis view
(top right), where VCAM-1 expression can be located around the aortic ring. (B) h e near-infrared
signal (NIRF) from the aortic valve commissure, which is coni rmed by immunohistochemical
staining (bot om right, dark area). With permission from Aikawa et al . (2007).
SUMMARY
• Molecular imaging of endothelial adhesion molecules may lead to
substantial changes in the way that many disease processes are diagnosed,
treated and monitored.
• Ultrasound imaging is arguably the most extensively used modality to date
and has been used to image adhesion molecule expression in a variety of
animal disease models (e.g. transplant rejection, ischemia-reperfusion
injury).
• Several probes have been developed for adhesion molecule imaging using
MRI and have been used to successfully image vascular and cerebral
inl ammation, ischemia, and angiogenesis in animal models.