Rational design of flow phantoms for evaluation of new Doppler ultrasound techniques

With various advances in Doppler ultrasound technology such as high-frame-rate flow imaging and vector flow estimation, there is a growing need to devise appropriate phantoms that can holistically assess the accuracy of the derived flow estimates. Straight-tube models simply cannot serve this purpose, nor can spinning discs that simulate tissue motion instead of flow dynamics. In this presentation, we shall highlight a series of innovations in devising flow phantoms that can foster meticulous performance evaluation of new Doppler ultrasound techniques. First to be discussed is the design of a novel wall-less spiral phantom with omnidirectional flow (i.e., from 0 to 360 deg). With a three-loop spiral geometry with 4 mm lumen diameter and 5 mm pitch, this phantom was developed using a combination of computer-aided design, 3-D printing of vessel core, and lost-core casting with polyvinyl alcohol cryogel. It is useful for testing the performance of flow vector estimators. The design of anatomically realistic flow phantoms will also be described, and a representative example based on patient-specific aneurysm geometry will be highlighted. In addition, methodological innovations in developing walled arterial phantoms will be presented. Their application will be demonstrated in the context of testing new vascular imaging techniques that simultaneously track wall motion and blood flow.With various advances in Doppler ultrasound technology such as high-frame-rate flow imaging and vector flow estimation, there is a growing need to devise appropriate phantoms that can holistically assess the accuracy of the derived flow estimates. Straight-tube models simply cannot serve this purpose, nor can spinning discs that simulate tissue motion instead of flow dynamics. In this presentation, we shall highlight a series of innovations in devising flow phantoms that can foster meticulous performance evaluation of new Doppler ultrasound techniques. First to be discussed is the design of a novel wall-less spiral phantom with omnidirectional flow (i.e., from 0 to 360 deg). With a three-loop spiral geometry with 4 mm lumen diameter and 5 mm pitch, this phantom was developed using a combination of computer-aided design, 3-D printing of vessel core, and lost-core casting with polyvinyl alcohol cryogel. It is useful for testing the performance of flow vector estimators. The design of anatomically realistic ...