Power Doppler Sonography is a technique based on the total integrated doppler power spectrum: its signal is linked to the power of doppler signal and to the number of red cells present in the vessel, being much less dipendent on the direction of blood flow than velocity or variance doppler processing. It optimizes detection of moving blood with a velocity of 0.8 cm/sec to 6 cm/sec. It is very susceptible to motion caused by scanhead placement and patient's breathing, and presents an homogenous, single color: it is nearly independent of the insonation angle and is much less angle- dependent. In Neurosonolegy it is useful in the study of residual lumen in high-grade stenosis, in the differential diagnosis of pseudo-occlusion of internal carotid artery from total occlusion, and in the visualization of intracranical blood flow. In first and second indication it is more sensitive than Color-Doppler because it is based upon the amplitude of signal, that depends from the presence and eventually from the number of blood red cells: so in a high-grade stenosis where there is a very low blood flow, it makes it notice by means the visual injection of the vessel. Power Doppler Sonography is useful in the visualization of intracranial cerebral arteries, principally of middle cerebral artery, anterior cerebral artery, intracranial vertebral artery, and basilar artery, making possible the evaluation of some doubtful results of 'blind' TCD, and making possible the identification of aneurysms and MAV.
|Translated title of the contribution||Utility of the Power Doppler Sonography|
|Number of pages||6|
|Journal||Rivista di Neurobiologia|
|Publication status||Published - 1997|
ASJC Scopus subject areas