Experimental Validation of Color Doppler Velocity Measurement for Ultrasonic-Measurement-Integrated Simulation of Blood Flow

Abstract

Cardiovascular diseases are closely related to blood flow. Ultrasonic-Measurement-Integrated (UMI) simulation, in which results of ultrasonic measurement are fed back to the flow simulation, was proposed in a previous study in order to reproduce the real blood flow accurately and efficiently. The usability of the UMI simulation was confirmed by numerical experiment, but the effectiveness of this simulation was strongly affected by the accuracy of the ultrasonic measurement. In this paper, we examined the accuracy of a commercial ultrasonic measurement device by an experiment with a PVA-H straight tube phantom. By analyzing the measured color Doppler images for a developed laminar flow inside the phantom, we obtained the relationship between the color Doppler value and the Doppler velocity (C-V relationship). It was revealed that the original C-V relationship provided in the device as a color bar was not suitable for quantitative evaluation of Doppler velocity to be used in UMI simulation. Compared with the original C-V relationship, the present C-V relationship results are in far better agreement with the analytic solution. Investigation of the normalized error confirmed that the result obtained with the present C-V relationship was reliable in cases of relatively high Reynolds number in the flow domain except near the wall. The two signal conditioning factors of the device had little influence on the Doppler velocity. Finally, we investigated the effect of temporal and spatial averaging of ultrasonic measurement data to clarify the relation between the number of averagings and the level of agreement with the analytic solution.

Poly(vinyl alcohol) gel ultrasound phantom with durability and visibility of internal flow

“…Results and discussion Figure 2 shows variations of the acoustic properties of PVA gel for ultrasound with the PVA concentration, c PVA , at a constant DMSO concentration of c DMSO = 48 mol% without glass beads (c particle = 0 mass%). These PVA gels are comparable to those used to create flow phantoms in former studies [27,28]. The acoustic properties do not approximate those of in vivo soft tissue, implying that PVA gels are not suitable for tissue-mimicking.…”

“…PVA gel shows fine optical transparency with the addition of dimethyl sulfoxide (DMSO) [26]. Transparent PVA gel flow phantoms have been developed for the training of medical personnel in catheter intervention for cerebral aneurysms [27] and for experimental validation of ultrasound color Doppler measurement with conventional medical ultrasonic equipment [28]. However, the appropriateness of the acoustic properties of those transparent PVA gels has not been examined.…”