[Assessment of the rate of successful transcranial Doppler recording through the temporal windows in Japanese with special reference to aging and sex].

Transcranial Doppler method (TCD), newly developed in 1982, is ultrasound technology that measures physiologic parameters of blood flow in the major intracranial arteries. A major limitation of TCD is that, in some individuals, satisfactory recording is not possible, especially through the temporal windows. The purpose of the present study is to assess the rate of successful recording in TCD through the temporal ultrasonic windows in Japanese with special reference to aging and sex. In 423 Japanese (244 males and 179 females) aged from 25 to 93 years, measurement of blood flow velocity in basal cerebral arteries was performed by transcranial Doppler velocimeter with a 2 MHz pulsed wave Doppler probe. The signal was successfully recorded in 299 of 423 Japanese (71%). In Japanese males, successful measurement was more frequent (206/244; 84%) than in Japanese females (93/179; 52%). The rate of successful recording was evaluated in every decade from the twenties to the eighties, and it was found to decrease significantly according to age (100%, 94%, 91%, 74%, 66%, 67%, and 46%, respectively). In females, it significantly decreased in those older than 50 years old (100%, 100%, 93%, 61%, 36% 43%, and 27%, respectively), but not in males (100%, 88%, 89%, 81%, 88%, 83%, and 69%, respectively). These findings suggest that this noninvasive method has clinical usefulness for evaluating intracranial circulation but has limitation for assessing the intracranial lesions of elderly Japanese women.