Transcranial Doppler Ultrasonography (TCD) is a non-invasive diagnostic imaging technique used to assess the blood flow patterns within the brain's blood vessels. It involves the use of high-frequency sound waves, specifically ultrasound, to create images and measure the velocity and direction of blood flow in the major arteries and veins of the brain.
During the TCD procedure, a handheld device called a transducer is placed on the surface of the skull, usually at specific locations called "windows," which allow the sound waves to penetrate the skull and reach the blood vessels. The transducer emits sound waves that bounce off the moving blood cells within the vessels, creating echoes that are then converted into visual and auditory signals by a computer. These signals are displayed on a monitor, providing real-time information on the blood flow dynamics.
Transcranial Doppler Ultrasonography is a valuable tool in the diagnosis and monitoring of various neurological conditions, such as strokes, aneurysms, arteriovenous malformations, and vasospasms. It is also used to evaluate conditions like intracranial stenosis, emboli, and intracranial hypertension. By assessing the velocity and patterns of blood flow, TCD aids in determining the presence, severity, and location of vascular abnormalities within the brain.
TCD is a safe, non-invasive, and cost-effective diagnostic modality, making it widely accessible for evaluating cerebral blood flow abnormalities. Its application extends beyond diagnostic purposes, as it can also guide the management of specific vascular conditions or guide therapeutic interventions like monitoring during cardiac surgeries or interventions that affect brain circulation.
