CONSENSUS ON MICROEMBOLUS DETECTION BY TCD

Transcranial Doppler ultrasound is capable of detecting microembolic m aterial, both gaseous and solid, within the intracranial cerebral arte ries. To avoid discrediting this promising and exciting new technique, experts in this field met in January 1997 in Frankfurt, Germany, to d iscuss the limitations and problems of embolus detection and to determ ine guidelines for its proper use in clinical practice, as well as in scientific investigations. In particular, the authors suggest that stu dies report the following parameters: (1) ultrasound device, (2) trans ducer type and size, (3) insonated artery, (4) insonation depth, (5) a lgorithms for signal intensity measurement, (6) scale settings, (7) de tection threshold, (8) axial extension of sample volume, (9) fast Four ier transform (FFT) size (number of points used), (10) FFT length (tim e), (1 1) FFT overlap, (12) transmitted ultrasound frequency, (13) hig h-pass filter settings, and (14) recording time. There was agreement t hat no current system of automatic embolus detection has the required sensitivity and specificity for clinical use.