These case reports demonstrate the potential of different contrast-specific
modalities for the assessment of pathologic brain perfusion using contrast ultrasound imaging. In a small study analyzing local correlations of ultrasound perfusion parameters of bolus kinetics with the occurrence of a perfusion-diffusion mismatch on Stroke MRI (penumbra) thresholds were calculated. Penumbra could be assumed if the relative time delay exceeded 4 s and the relative signal amplitude exceeded 1/3 . These preliminary data should be verified by a prospective study. Besides the high potential of ultrasound perfusion imaging as a fast, semi-invasive bedside method to evaluate supratentorial brain perfusion in acute ischemic stroke patients, there are some drawbacks like the insonation artifacts, which occur in most of the patients and the inability to scan the whole brain. Besides these technical limitations there are potential Z-VAD-FMK chemical structure p38 MAPK assay side effects of the new contrast agents, which restrict the employment of these substances in severe cardiac or pulmonary disease. Prof. Seidel is employed by Asklepios
Kliniken Hamburg GmbH and is professor of Neurology at the University of Luebeck, Germany. He has previously received unrestricted educational grants from Schering, Bracco Imaging SpA, Philips Medical Systems, Boehringer Ingelheim, Solvay, Bayer HealthCare, Biogen idec, Desitin, Merck Serono, Meda, MSD, Novartis Neuroscience, Talecris, UCB, Grunenthal, Lundbeck, Merz, Teva and Sanofi Aventis. He has worked together with Bracco Imaging SpA
and Philips Medical Systems in research projects funded by the European Union. “
“Compared to conventional transcranial Doppler sonography (TCD), transcranial color duplex sonography (TCDS) is able to measure much more accurately on the basis of angle-collected velocities in the intracranial major vessels. Furthermore, TCDS is able to visualize intracranial lesions in stroke , severe head O-methylated flavonoid injury , and other neurological disorder cases . Utilizing ultrasound contrast agents (UCA), TCDS has been able to evaluate brain tissue perfusion non-invasively, particularly in ischemic stroke patient investigations  and . Possibilities of quantitative measurements have been evaluated in an identical way to neuroradiological perfusion imaging, based on the bolus dye-dilution principle. However, quantitative reliability has not yet been established, due to problems of skull- and depth-dependent ultrasound attenuation, shadowing effects, bubble saturation, and low data reproducibility (the latter due to UCA administration methods, transducer fixation, data analysis, etc.)  and . Transducer holders or probe fixation devices for conventional TCD monitoring have been introduced into clinical settings , ,  and . However, a transducer holder for TCDS has yet to be clinically introduced. We have developed and improved such a transducer holder (Sonopod) (Fig.