Transcranial Doppler Ultrasound: Practice Standards Part I. Test Performance and Interpretation

Scientific statement

Journal of Neurosonology 2016;8(1):1-13.

경두개도플러초음파 표준검사지침 1부. 검사의 시행과 해석

Abstract

Transcranial Doppler ultrasound (TCD) has been widely used to assess and monitor cerebrovascular hemodynamics. TCD has strong advantages of easy accessibility in time and space, and non-invasiveness over other imaging techniques. However, in addition to the dependency of examiner’s skills and experience, lack of the standardized scanning protocols is one of obstacles to overcome. Based on the present reports and expert’s consensuses, a routine TCD evaluation should include velocity measurement and waveform recording of the major intracranial vessels of circle of Willis and the extracranial carotid arteries via three transcranial and one submandibular insonation. TCD examination should contain 1) the transtemporal approach for the middle cerebral, anterior cerebral and posterior cerebral arteries, 2) the transorbital approach for the ophthalmic artery and internal carotid artery siphon 3) the transforaminal approach for both vertebral and basilar arteries. A routine TCD technique in combination with headframe with dual probe fixation devices provide real-time flow monitoring. Therefore, TCD monitoring could be used for hemodynamic change in various clinical situations. Real-time flow monitoring using TCD gives hemodynamic information to clinicians regarding to successful recanalization in in the occluded vessel of acute ischemia, plaque stability by detecting microemboli and collateral reservoir by vasomotor reactivity test. Beyond cerebrovascular disease, hemodynamic information is useful in assessing brain death, subclavian steal, syncope, rotational vertebral artery syndrome and perioperative monitoring. As TCD has expanded clinical utilities from cerebrovascular disease to other neurological diseases for the last thirty years, standardization of TCD protocol is essential for clinical practice as well as the future clinical studies. The authors reviewed the present literatures and expert's consensuses, and made the current scientific statements of TCD for proper application and interpretation.