A hydraulic engineer could tell you that unusual flow patterns are likely where a rapidly moving fluid diverges into two streams—at the carotid bifurcation, for example.
But it was only during the last year, and only with a very advanced ultrasonic scanning system, that scientists demonstrated for the first time a phenomenon predicted by theoreticians: an area of reverse blood flow just beyond the carotid bifurcation. This phenomenon, called a "boundary layer" or "flow separation" in hydraulic engineering parlance, is the basis for a newly emerging theory of how and why atherosclerosis develops.
The finding of a boundary layer was reported at the recent Joint International Conference on Stroke and Cerebral Circulation in New Orleans by Christopher P. L. Wood, MB, BS, of the British Medical Research Council's Clinical Research Centre in Harrow, England. While a visiting fellow in the neurology department at the Bowman Gray School of Medicine in