What is a characteristic of significant stenosis detected by TCD?

Significant stenosis detected by Transcranial Doppler (TCD) is characterized by a localized increase in mean velocity within the affected segment of the artery. When there is a narrowing of the artery due to stenosis, the blood flow velocity increases as it passes through the constricted area. This phenomenon occurs because the same volume of blood is forced through a smaller opening, according to the principle of continuity in fluid dynamics. Therefore, the measurement of increased mean velocity is a critical indicator that helps clinicians assess the severity of the stenosis.

In clinical practice, identifying such increases in velocity allows for the evaluation of potential hemodynamic significance, guiding further management and intervention strategies. This characteristic is essential for diagnosing cerebrovascular conditions and determining the appropriate course of treatment.