Contrast-Enhanced Ultrasound Perfusion Imaging in Acute Stroke Patients

In acute stroke, different sonographic methods can be used to assess structural and hemodynamic compromise. Structural abnormalities of brain parenchyma such as primary intracerebral hemorrhage (ICH) and epiphenomena such as midline shift can be detected by native transcranial B-mode ultrasound. Moreover, transcranial Doppler provides a functional approach to intracranial hemodynamics and may assist in predicting ICH growth and global intracranial pressure increase. New ultrasound technologies allow the visualization of ultrasound contrast agents in the cerebral microcirculation. According to recent data, ultrasound perfusion imaging provides additional information for the diagnosis of ICH and may differentiate ischemic from hemorrhagic stroke. This review summarizes the impact of these different transcranial ultrasound methods on diagnosis and monitoring of ICH.

Section: Value Of Echo Contrast Agent Microbubbles For Ich Assessmentmentioning

confidence: 99%

Diagnosis of Intracerebral Hemorrhage with Transcranial Ultrasound

Meyer‐Wiethe

Sallustio²,

Kern³

2009

“…9 Microvascular map of left MCA infarction (arrows) characterized by absent or diminished contrast agent. The excellent infarction demarcation compares well with MRI diffusion-weighted imaging (bottom images) [90]. …”

Section: Examination Of the Microcirculation – Brain Perfusion Imagingmentioning

confidence: 92%

“…The excellent infarction demarcation compares well with MRI diffusion-weighted imaging (bottom images) [90]. …”

Section: Examination Of the Microcirculation – Brain Perfusion Imagingmentioning

confidence: 92%

See 1 more Smart Citation

Ultrasound Contrast Agents in Ischemic Stroke

Seidel

Meairs²

2009

Self Cite

The general indication for the use of ultrasound contrast agents in neurosonologic applications is an insufficient signal-to-noise ratio when investigating the cerebral macro- and microcirculation. Clinical problems that are often encountered in native sonography are ‘no flow, slow flow and low flow’ phenomena. In these cases, ultrasound contrast agents are used to differentiate between vessel occlusion and insufficient insonation conditions, as well as for the detection of very slow blood flow velocities and low flow volumes. Echo-contrast agents significantly increase the success rate of transcranial color duplex examinations of patients with acute cerebrovascular disease. Ultrasound contrast imaging also allows assessment of the cerebral microcirculation. There are a number of techniques available for performing perfusion studies. These generally utilize high mechanical index imaging, since until recently lower acoustic outputs were unable to detect microbubbles in the brain. New-generation microbubbles in combination with very sensitive contrast-specific ultrasound techniques now enable real-time visualization of stroke. Moreover, destruction sequences with assessment of microbubble replenishment using real-time, low mechanical index imaging are now available. This article reviews of state-of-the-art contrast-specific imaging techniques for ultrasound evaluation of acute stroke patients.

“…Their primary application is currently in echocardiography, for ventricular opacification and delineation of endocardial borders [1, 2], although they have also been used successfully for the assessment of systolic function and left ventricular volume [3], and for identifying myocardial infarction and coronary artery stenoses [4, 5]. The development of harmonic imaging, together with advances in three-dimensional visualisation techniques, has further enabled mapping of the microcirculation using microbubbles; for example, in the characterisation of tumour vascularity [6, 7], and also in the brain, offering substantial advantages for the assessment of stroke patients [8]. Other, non-vascular, applications of microbubbles include assessment of fallopian tube patency [9] and detection of utereric reflux [10].…”

Section: Introductionmentioning

confidence: 99%

Physical Principles of Microbubbles for Ultrasound Imaging and Therapy

Stride¹

2009

Microbubble ultrasound contrast agents have been in clinical use for more than two decades, during which time their range of applications has increased to encompass echocardiography, Doppler enhancement, perfusion studies and molecular imaging, as well as a number of therapeutic applications including drug delivery, gene therapy, high-intensity focused ultrasound treatments and sonothrombolysis. The aim of this article is to review the different types of microbubble agent, their physical behaviour and the mechanisms underlying their effectiveness in imaging and therapeutic applications.