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ORIGINAL RESEARCH article

Front. Phys.
Sec. Medical Physics and Imaging
Volume 12 - 2024 | doi: 10.3389/fphy.2024.1461255
This article is part of the Research Topic Development of Task Specific Phantoms and Test Objects for Medical Imaging View all 8 articles

Adaptive Design of Ultrasound Phantoms using Additive Manufacturing

Provisionally accepted

The final, formatted version of the article will be published soon.

    The image formation process of conventional pulse-echo Ultrasound mainly uses the backscattered amplitude and assumes constant attenuation and speed of sound in the penetrated media. Thus, many commercially available ultrasound imaging phantoms use only a limited choice of materials with simple geometric shapes. Part of today's research in ultrasound is to gain more information on the acoustic properties of the object imaged. These advanced imaging and reconstruction procedures require more complicated phantom designs that contain different materials with precisely designable acoustic properties for validation and quality assurance (QS). To fabricate such phantoms, we produced molds for casting ultrasound phantoms using additive manufacturing. Phantom materials used were based on agar and polyvinyl alcohol. To adapt the speed of sound glycerol was added to the mixtures. As glycerol diffuses out of the phantom material, polluting the surrounding water, we designed a watertight sample holder. The effect of the freeze-thaw cycles (FTCs) on the acoustic properties of the polyvinyl alcohol (PVA)-based phantoms was also investigated. Speed of sound and attenuation were determined for both phantoms materials, and Shore hardness measured for the PVA-based phantoms. Shore hardness of the PVA phantoms increased by up to 79% of the initial value with increasing number of freeze-thaw cycles, but showed a saturation after 5 FTCs. However, the number of FTCs had only a small effect on the speed of sound and attenuation, as the sound speed increased slightly from 1530.14 m/s to 1558.53 m/s, (1.86\%) and the attenuation exhibited only an increase of 6.75\%. In contrast, differences of around 100 m/s in the speed of sound in the PVA phantoms (from 1558.53 to 1662.27 m/s), as well as in the agar-based phantoms (from 1501.74 to 1609.36 m/s) could be achieved by adding glycerol, making these materials appropriate candidates for the design and fabrication of US phantoms with defined sections and details with different speed of sound and attenuation. The use of the sample holder showed only an influence of 0.63% on the measured speed of sound.

    Keywords: Ultrasound phantom, speed of sound, attenuation, Additive manufacturing, Polyvinyl Alcohol, Agar

    Received: 08 Jul 2024; Accepted: 13 Dec 2024.

    Copyright: © 2024 Zalka, Köhrer, Songsaeng, Homolka, Kollmann, Hummel and Figl. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Michael Figl, Medical University of Vienna, Vienna, Austria

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.