Imaging of Abdominal Aortic Aneurysm: The Present and the Future

Hao      Hong; Yunan      Yang; Bo      Liu; Weibo      Cai

Abstract

Abdominal Aortic Aneurysm (AAA) is a common, progressive, and potentially lethal vascular disease. A major obstacle in AAA research, as well as patient care, is the lack of technology that enables non-invasive acquisition of molecular/ cellular information in the developing AAA. In this review we will briefly summarize the current techniques (e.g. ultrasound, computed tomography, and magnetic resonance imaging) for anatomical imaging of AAA. We also discuss the various functional imaging techniques that have been explored for AAA imaging. In many cases, these anatomical and functional imaging techniques are not sufficient for providing surgeons/clinicians enough information about each individual AAA (e.g. rupture risk) to optimize patient management. Recently, molecular imaging techniques (e.g. optical and radionuclide- based) have been employed to visualize the molecular alterations associated with AAA, which are discussed in this review. Lastly, we try to provide a glance into the future and point out the challenges for AAA imaging. We believe that the future of AAA imaging lies in the combination of anatomical and molecular imaging techniques, which are largely complementary rather than competitive. Ultimately, with the right molecular imaging probe, clinicians will be able to monitor AAA growth and evaluate the risk of rupture accurately, so that the life-saving surgery can be provided to the right patients at the right time. Equally important, the right imaging probe will also allow scientists/clinicians to acquire critical data during AAA development and to more accurately evaluate the efficacy of potential treatments.

Keywords: Abdominal aortic aneurysm (AAA), anatomical imaging, functional imaging, magnetic resonance imaging (MRI), molecular imaging, positron emission tomography (PET), ultrasound, vascular disease, computed tomography, endovascular aneurysm repair, Ultrasonography, extracellular ma-trix, matrix metalloproteinase-2, MMP inhibitor, doxycycline, pro-inflammatory cytokines, TNF, IL-1, IL-6, (IFN), CCR2, blockade of MCP-1, SMC apoptosis, sound attenuation, imaging algorithm, 3-dimensional (3D) imaging, Tissue Doppler imaging, CT angiography, 2D X-ray images, single-photon emission computed tomography, collimator, Tc-Labeled Red Blood Cells (RBCs), In-Labeled Platelets, Tc-Sestamibi, Thallium-201, arteriosclerosis, National Institutes of Health, magnetic reso-nance spectroscopy, OPTICAL IMAGING, vas-cular endothelial growth factor receptor, Tc-annexin V imaging, 18F-fluoro-deoxy-glucose, Coxiella burnetii-infected vascular grafts, calcified aneurysms, apoptosis, proteolysis