Aortic regurgitation, Doppler color flow proximal isovelocity surface area method
Although Doppler color flow mapping has been used to quantitate the severity of aortic regurgitation, this approach has various limitations. Doppler color flow mapping of a proximal isovelocity surface area (PISA) , defined by a blue-red aliasing interface, has been shown in vitro to be accurate for estimated volume flow rate across an orifice. Volume flow rate can be calculated as PISA X aliasing velocity. To evaluate the clinical applicability of the PISA method, we compared the regurgitant stroke volume estimated by the PISA method with the conventional pulsed Doppler method in 20 patients with aortic regurgitation. Mean systolic aliasing radius was calculated from color overlayed -mode (Q/M-mode) images. The aortic regurgitant stroke volume calculated by the PISA method correlated well with that calculated by the pulsed Doppler method(r=0.88, SEE=15 ml). Thus, the color Doppler PISA method can be applicable to calculating the regurgitant volume in patients with aortic regurgitation.