Transcranial Doppler ultrasonography

Transcranial Doppler ultrasonography is used to monitor blood flow velocity in the basal arteries (most data relate to flows in the arteria cerebri media)' and carotids. It is used to diagnose vasospasms and regional perfusion disorders, which can accompany brain trauma or subarachnoid hemorrhage. 'Vasospasm corresponds to the acceleration of blood flow in the monitored artery.

It is also important to compare the flow velocity in the "a. cerebri media" and the extracranial section of the "a. carotis interna". This method is 'sensitive in demonstrating a reduction in central cerebral circulation (stenosis, intracranial hypertension), it has the highest sensitivity for flow in the a. cerebri media.

It is not tied to the presence of a large fontanelle, it can also be performed in larger children and adults through a "thinner" part of the skull, usually temporal bone.

TCD is also used within specific tests, e.g. TCD response to changes in pCO2 concentration, dynamic test of autoregulation, transient hyperemic response test (after short compression of the carotid artery), continuous TCD analysis with respiratory wave recording, etc. This is a method of increasing importance.

Related Articles

 * Doppler ultrasonography in medicine • Doppler ultrasonography
 * Doppler imaging • Doppler phenomenon
 * Doppler echocardiography • Fetal Doppler • Doppler flowmeter

Source

 * HAVRÁNEK, Jiří: Other monitoring.