CPT® Code 93892

A transcranial Doppler study is a non-invasive ultrasound procedure used to assess blood flow in the intracranial arteries, specifically for the purpose of detecting emboli. In this context, emboli refer to small particles or clots that can travel through the bloodstream and potentially cause blockages in the cerebral arteries. The study is conducted without the use of intravenous microbubble injection, which is a contrast agent typically used in other imaging studies to enhance visualization. Instead, the detection of emboli relies on the identification of short-duration, high-intensity signals that are generated by the Doppler ultrasound as it measures the movement of blood cells and any embolic material present in the blood flow. The intensity of these signals varies based on the density of the embolus compared to the surrounding blood cells, with gaseous emboli producing the highest intensity signals, while solid emboli, such as those formed from thrombotic, platelet, or atheromatous material, yield slightly lower intensity signals. During the procedure, a gel is applied to the patient's skin to facilitate the transmission of ultrasound waves. A handheld Doppler probe is then positioned on the skin, typically over the temporal bone, and directed at the middle cerebral arteries (MCA) on both sides of the head. Continuous monitoring of blood flow in the MCAs is performed, and the data is recorded on a specialized computer system that provides both auditory and visual feedback. A computer algorithm analyzes the recorded data to assist in identifying any high-intensity embolic signals, which the physician subsequently reviews to distinguish between genuine embolic signals and artifacts. Finally, the physician compiles a written report summarizing the findings of the study, which is essential for further clinical decision-making.