Amplitude information from Doppler color flow mapping systems: A preliminary study of the power mode

Abstract

The flow of a saline-glycerin solution with sand particles through a continuous in vitro flow system was imaged by using two commercially available Doppler color flow mapping systems in a power mode (Toshiba SSH-160A and Advanced Technology Laboratories [ATL] Ultramark 9). The images generated from seven solutions with particle concentrations ranging from 0.0001 x 10(12) to 6 x 10(12) particles/liter and a mean velocity of 30 cm/s measured with use of pulsed Doppler ultrasound were used to examine the dependence of the power mode on particle concentration. To examine the velocity dependence, 20 mean velocities ranging from 0.1 to 0.53 m/s (3 to 30 liters/min) and three particle concentrations (1, 3 and 6 x 10(12) particles/liter) in the solution were used. The recorded images were digitized and analyzed off-line. The SUM values, or the adjusted color intensity levels in delineated areas of interest in the displayed flow, were compared. In general, the power mode was sensitive in displaying slower velocity flows; in the selected particle concentration and velocity ranges, it was both velocity and concentration dependent. The specific dependence differed for the two color flow mapping systems.

Power Doppler Imaging of the Fetal Upper Aerodigestive Tract Using a 4‐Point Standardized Evaluation

“…This produced an unacceptable degree of washout when compared with PD imaging, a finding consistent with reports in the general sonographic literature. 15,16 Low-velocity laminar flow on PD imaging produced a relatively smooth column of color and allowed topographic details such as eddy currents to be seen in high-flow activities or when the jets moved through nonuniform conduits such as the glottis.…”

“…Whereas CD imaging represents the spectrum of flow velocity and direction, PD imaging represents the amplitude, or intensity, of the Doppler signal. 15,16 Thus, PD imaging has increased sensitivity for detection of lowamplitude signals regardless of direction. At early gestational ages (GAs), the detection of very small, low-velocity bolus swallows is advantageous.…”

Power Doppler sonography of the kidney: Effect of Valsalva's maneuver

“…The relationship between the true blood flow volume and the total integrated Doppler power remains unclear. However, according to Parro et al's study, 8 power Doppler sonography is dependent on the concentration of red blood cells. Therefore, it appears that the total integrated Doppler power is, if not proportional to, at least dependent on the blood flow volume.…”