When interpreting a TCD exam, what suggests a significant flow abnormality?

In the context of a Transcranial Doppler (TCD) exam, significant flow abnormalities are typically indicated by changes in blood flow velocity patterns. Increased peak systolic velocities suggest that there is a heightened flow of blood in the vessels being evaluated, which can be indicative of various conditions, such as stenosis or vasospasm.

Increased peak systolic velocities often result from turbulent flow associated with narrowing of the vessel lumen. This abnormal increase can signal potential pathologies that may require further investigation or intervention. Thus, when interpreting a TCD exam, observing elevated peak systolic velocities serves as an important marker pointing toward significant vascular changes or abnormalities.

The other options reflect conditions that are less indicative of significant flow abnormalities. For instance, a decreased frequency shift might suggest reduced flow or occlusion, which does not necessarily imply a significant abnormality on its own. Altered directional flow changes, while important, need to be evaluated in the context of other findings; they don't solely hint at significant abnormalities without accompanying velocity changes. A stable baseline amplitude typically indicates normal flow and suggests that there are no significant changes occurring in the blood vessel being examined. Therefore, increased peak systolic velocities stand out as the most relevant indication of significant flow abnormalities in TCD interpretation