A new Doppler method for quantification of volumetric flow: in vivo validation using color Doppler.
OBJECTIVE
This study was designed to assess the accuracy of a new Doppler method for quantification of volumetric flow in vivo.


BACKGROUND
Noninvasive assessment of volumetric flow through heart valves and the great vessels remains a clinical goal. We present a new method for quantification of volumetric flow based on color Doppler mapping that computes velocity vectors over a surface normal to the point of scanning. This Doppler technique assumes only the incompressibility of the fluid. The method is basically independent of the angle of incidence between the ultrasound beam and the direction of blood flow and includes variations of flow area.


METHODS
The color Doppler method was tested in seven anesthetized pigs by measuring pulmonary volumetric flows using multiplane Doppler echocardiography. The results were compared with those obtained by the thermodilution technique. In addition, volumetric flows across the mitral valve were determined in 10 normal volunteers by transthoracic Doppler echocardiography and compared with flows obtained with velocity-encoded magnetic resonance imaging (MRI).


RESULTS
The mean value of the differences between the thermodilution technique and color Doppler were -0.16 +/- 0.94 liter/min for pulmonary volumetric flows (mean value of differences for [Thermodilution-Color Doppler] +/- 2 SD of differences). The mean value of the differences between MRI and color Doppler were 0.21 +/- 0.83 liter/min for mitral valvular volumetric flows (mean value of differences for [MRI-Color Doppler] +/- 2 SD of differences).


CONCLUSIONS
The method showed close agreement with thermodilution and MRI for assessment of volumetric flow in vivo. It is therefore a noninvasive method with potential applications for cardiac output measurement and for quantification of volumetric flow of valvular insufficiency and restrictive lesions.
Kim
W Y
WY
Department of Thoracic and Cardiovascular Surgery, Skejby Sygehus, Aarhus University Hospital, Denmark.
Poulsen
J K
JK
Terp
K
K
Staalsen
N H
NH
D000328:Adult; D000818:Animals; D001011:Aorta / Q000000981:diagnostic imaging / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology*; D003627:Data Interpretation, Statistical; D018618:Echocardiography, Doppler, Color / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008432:Mathematical Computing; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology; D012016:Reference Values; D015203:Reproducibility of Results; D013552:Swine; D013815:Thermodilution