Comparison of laser Doppler and Doppler ultrasound in lower limb vascular diagnosis

This study represents a preliminary investigation into the use of laser Doppler flowmetry in lower limb vascular diagnosis. The method is compared with the accepted method of continuous wave Doppler ultrasound. Fifty-six patients with symptoms of lower limb vascular disease were investigated consecutively and independently using both techniques. In approximately two-thirds of patients the two methods showed broad agreement in their classification of disease severity (correlation coefficient = 0.63, P less than 0.001, n = 41). However, about 30% of those studied had impaired microvascular responses on laser Doppler evaluation with no detectable major vessel disease on continuous wave ultrasound investigation. The results indicate that more information is obtained about a subject's vascular status when results from both methods are combined. Thus laser Doppler flowmetry may be useful adjunct to Doppler ultrasound and segmental pressure measurements in the vascular laboratory.