Color Doppler echocardiographic determination of mitral regurgitant flow from the proximal velocity profile of the flow convergence region

Effect of Dynamic Flow Rate and Orifice Area on Mitral Regurgitant Stroke Volume Quantification Using the Proximal Isovelocity Surface Area Method

“…Quantitative methods used for comparison, such as the quantitative Doppler method (11,13,18,28,32) or combined thermodilution and quantitative angiography (8,21), were limited by indirect measurements of regurgitant flow prone to error, whereas angiographic grading did not provide absolute values of MRSV (11,13,33). Compared with this, MRI provides accurate estimates of MRSV from direct measurements of mitral inflow and aortic outflow from integration of flow over flow cross-sectional area and time (29,34), which can be used for reference in clinical studies (35).…”

“…The PISA-VTI approach describes the standard PISA approach multiplying single-point MRFR times the ratio of VTI and peak velocity of MR flow (3,8,11,12). First, peak MRFR is obtained by using the hemispheric PISA formula 2 ϫ r 2 ϫ v(Ny) as described earlier (Fig.…”

Aortic regurgitant flow by color Doppler measurement of the local velocity 7 mm above the leak orifice –¶Part 1: in vitro measurements

“…For curve fitting of the accelerating velocity profiles, a multiplicative regression model (y = ax b ) was used, as described elsewhere (6,9). For the analysis of the overall v (7 mm) , we selected 1 relative velocity profile for each combination of orifice type and size, each profile derived from 1 measurement with the setup for high velocities and 1 with the setup for low velocities, each measurement consisted of the mean of ≥ 10 color frames.…”

“…These studies focused on flow approaching the orifice equally from all directions, in the absence of lateral wall which might confine the flow convergence region toward the sides (6-8, 15, 27, 29, 30). Based on these in vitro data, atrioventricular valve regurgitation could be assessed satisfactorily by ultrasound color Doppler (1,5,9,13,17,18,22).…”

Quantification of Mitral Regurgitation by the Proximal Flow Convergence Method—Comparison of Transthoracic and Transesophageal Echocardiography

“…1,2 In addition to measuring the spatial distribution of the regurgitant jet within the left atrium, color Doppler imaging of the flow convergence region proximal to the regurgitant orifice has been applied for quantification of mitral regurgitation using transthoracic (TTE) or transesophageal echocardiography (TEE). [3][4][5][6][7][8][9][10] Since TEE is a semi-invasive approach for diagnosis and quantification of mitral regurgitation, a noninvasive method would be preferable in clinical routine. Thus far, no data exist to indicate whether TTE may be comparable with TEE for the detection and quantification of mitral regurgitation using the proximal flow convergence method, and the purpose of this study was to make such a comparison.…”