Transcranial Doppler Ultrasonography

Transcranial Doppler ultrasonography (TDU) is covered for assessing collateral blood flow and embolization during carotid endarterectomy; evaluating patterns/extent of collateral circulation in severe stenosis/occlusion including Moyamoya; assessing suspected patent foramen ovale/paradoxical embolism; assessing suspected brain death; and assessing stroke risk in children 2–16 years with sickle cell anemia (re‑screening is recommended about every 6 months). TDU is excluded (considered experimental/investigational) for all other indications—e.g., testing autoregulation, brain tumors, cerebral venous/sinus thrombosis, or monitoring response to antithrombotic therapy—because effectiveness is not established.

"Screening of children aged 2 to 16 years with sickle cell disease for assessing stroke risk (AAN report: "Screening of children aged 2 to 16 years with sickle cell disease for assessing stroke risk..."