Brain perfusion imaging using contrast agent specific imaging modes

Contrast agents enable the visualization of bigger blood vessels in the brain, e.g. the circle of Willis, in color- or power mode, which is a challenging task due to the high attenuation of the transtemporal bone window. Moreover, contrast agent specific imaging mode show potential to visualize microcirculation. Such imaging modes, three of which were investigated, mostly exploit non-linear scattering from microbubbles and the destruction of microbubbles by ultrasound. Functional images are formed from image sequences by locally analyzing the time-intensity-curves after a bolus injection of contrast agent.