Preferred technique for blood flow volume measurement in cerebrovascular disease

Background and Purpose-A noninvasive reliable technique that can reveal cer ebral blood flow volume could be a valuable tool in screening programs for stroke prevention. Tn diagnostic ultrasonography, spectral Doppler imaging (SDI) is popular among sonologists and vascular technologists to estimate b lood flow volume despite its documented inaccuracy and the availability of the more accurate technique of color velocity imaging (CVI), The aim of the present study was to demonstrate the discrepancy of blood now volume estim ation with CVI and SDI with use of an "internal" standard. Methods-The common, internal, and external carotid arteries of 50 healthy s ubjects (22 men, 28 women, age range 19 to 54 years) were examined with CVI and SDI. The total blood now volume of the internal and external carotid a rteries was then compared with the ipsilateral common carotid artery flow. An accurate technique would demonstrate no difference. The difference (expr essed as a percent inconsistency) was therefore a measure of the accuracy o f the method. Results-The mean+/-SD inconsistency was found to be 10.6+/-8.3% for CVI and 27.9+/-14.3% for SDI, The difference in inconsistency between CVI and SDI in measurement of carotid blood flow volume was statistically significant ( P<0.01), Conclusions-CVI is more accurate than SDI in the determination of blood flo w volume in the carotid arteries. For noninvasive clinical estimation of ce rebrovascular blood flow volume, CVI quantification should be the preferred technique.