Contrast-enhanced ultrasound of the abdominal aorta – current status                     and future perspectives

Abstract. Ultrasound has been established as an important diagnostic tool in assessing vascular abnormalities. Standard B-mode and Doppler techniques have inherent limitations with regards to detection of slow flow and small vasculature. Contrast-enhanced ultrasound (CEUS) is a complementary tool and is useful in assessing both the macro- and microvascular anatomy of the aorta. CEUS can also provide valuable physiological information in real-time scanning sessions due to the physical and safety profiles of the administered microbubbles. From a macrovascular perspective, CEUS has been used to characterize aortic aneurysm rupture, dissection and endoleaks post-EVAR repair. With regard to microvasculature CEUS enables imaging of adventitial vasa vasorum thereby assessing aortic inflammation processes, such as monitoring treatment response in chronic periaortitis. CEUS may have additional clinical utility since adventitial vasa vasorum has important implications in the pathogenesis of aortic diseases. In recent years, there have been an increasing number of studies comparing CEUS to cross-sectional imaging for aortic applications. For endoleak surveillance CEUS has been shown to be equal or in certain cases superior in comparison to CT angiography. The recent advancement of CEUS software along with the ongoing development of drug-eluting contrast microbubbles has allowed improved targeted detection and real-time ultrasound guided therapy for aortic vasa vasorum inflammation and neovascularization in animal models. Therefore, CEUS is uniquely suited to comprehensively assess and potentially treat aortic vascular diseases in the future.

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Novel applications of contrast-enhanced ultrasound imaging in vascular medicine

VASA ◽

10.1024/0301-1526/a000244 ◽

2013 ◽

Vol 42 (1) ◽

pp. 17-31 ◽

Cited By ~ 61

Author(s):

Daniel Staub ◽

Sasan Partovi ◽

Stephan Imfeld ◽

Heiko Uthoff ◽

Thomas Baldi ◽

...

Keyword(s):

Contrast Agents ◽

Real Time ◽

Ultrasound Imaging ◽

Aortic Aneurysms ◽

Vasa Vasorum ◽

Diabetic Microangiopathy ◽

Contrast Enhanced Ultrasound ◽

Vascular Events ◽

Vascular Ultrasound ◽

Contrast Enhanced

The use of contrast-enhanced ultrasound (CEUS) for vascular imaging indications has increased dramatically during the last decade. Ultrasound contrast agents are gas-filled microbubbles that are injected into the bloodstream and serve as strict intravascular reflectors of ultrasound waves. Numerous studies have addressed the potential clinical use of CEUS in different vascular fields including the carotid arteries, the abdominal aorta, renal arteries and the kidneys. In this review article we discuss the clinical value of contrast agents in vascular ultrasound by enhancing the vascular lumen, and more important, their role as a tool to deliver high resolution, real-time images of microvascular perfusion. Specifically, CEUS imaging of the carotid artery provides a novel, non-invasive method not only to improve the delineation of the vessel wall, but also for the assessment of the vasa vasorum and the ectopic vascularization of the atherosclerotic plaque (intraplaque neovascularization); probably providing a window to risk stratify atherosclerotic lesions and individuals by identifying vulnerable plaques prone to rupture causing vascular events. CEUS imaging has also emerged as a novel diagnostic tool in various aortic pathologies and particularly for the detection of endoleaks following endovascular treatment of abdominal aortic aneurysms. It is also a valuable tool for the assessment of the tissue perfusion in native and transplanted kidneys providing information on perfusion deficits of the parenchyma. Furthermore, a real-time CEUS method has recently been developed to assess the skeletal muscle microcirculation which could be used to study patients with peripheral arterial occlusive disease or diabetic microangiopathy. In the future, the use of targeted microbubbles could further enhance and expand the diagnostic capabilities of current vascular ultrasound imaging by detecting specific molecular processes that play a role in the pathophysiology of vascular disease.

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