Principles of Cerebral Ultrasound Contrast Imaging

Abstract

Ultrasound contrast is gaining acceptance worldwide as an adjunct to conventional ultrasound imaging. It has clinical applications as diverse as liver disease detection and characterization, myocardial perfusion and wall motion studies, and imaging of cerebral vascularity and perfusion. This paper will focus on imaging techniques used for transcranial ultrasound contrast imaging. The interaction of ultrasound with the microbubbles in the contrast agent is complex and nonlinear. This has led to the development of a variety of imaging modes to improve contrast detection compared with non-contrast optimized modes. This article presents several of these imaging methods in such a way as to help users of ultrasound contrast in the clinic and in research to understand this rapidly developing field.

Current status and future developments of contrast-enhanced ultrasound of carotid atherosclerosis

“…Most commercially available ultrasound systems provide specific pulse sequences (eg, amplitude modulation or pulse inversion) that retrieve nonlinearities at low acoustic power, which are only exhibited by microbubbles. 26 These techniques enable the suppression of tissue in the image and allow the specific identification of individual microbubbles. Microbubble contrast agents enhance the arterial lumen, improving the delineation of the lumen, and consequently the detection of atherosclerotic plaques and vessel wall irregularities (Fig 1).…”

New Directions in the Dynamic Assessment of Brain Blood Flow Regulation

“…For example, combining TCD with microbubble contrasting agents allow for quantification of local changes in perfusion for measuring absolute volumetric flow (Powers et al, 2009). However, the interaction of ultrasound with microbubble contrast agents is complex and beyond the scope of this review; the reader is referred to (Powers et al, 2009) for a detailed review of the current state of contrast TCD technology. With or without contrast, a TCD machine is relatively inexpensive ($20,000 to $50,000 USD); moreover, TCD is easy to use and it is safe in healthy and disease states alike.…”

Point-of-Care Ultrasound in Neurology – Report of the EAN SPN/ESNCH/ERcNsono Neuro-POCUS Working Group

“…Whenever the quality of the temporal bone window is low, insufficient, or absent, or a large intracranial artery occlusion is suspected, an ultrasound echocontrast agent (UEA) may improve the sensitivity and specificity of the examination [43].…”