Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds

TY - JOUR

T1 - Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds

AU - Maneas, Efthymios

AU - Xia, Wenfeng

AU - Nikitichev, Daniil I.

AU - Daher, Batol

AU - Manimaran, Maniragav

AU - Wong, Rui Yen J.

AU - Chang, Chia Wei

AU - Rahmani, Benyamin

AU - Capelli, Claudio

AU - Schievano, Silvia

AU - Burriesci, Gaetano

AU - Ourselin, Sebastien

AU - David, Anna L.

AU - Finlay, Malcolm C.

AU - West, Simeon J.

AU - Vercauteren, Tom

AU - Desjardins, Adrien E.

PY - 2018/1/4

Y1 - 2018/1/4

N2 - Here we describe methods for creating tissue-mimicking ultrasound phantoms based on patient anatomy using a soft material called gel wax. To recreate acoustically realistic tissue properties, two additives to gel wax were considered: paraffin wax to increase acoustic attenuation, and solid glass spheres to increase backscattering. The frequency dependence of ultrasound attenuation was well described with a power law over the measured range of 3-10 MHz. With the addition of paraffin wax in concentrations of 0 to 8 w/w%, attenuation varied from 0.72 to 2.91 dB cm-1 at 3 MHz and from 6.84 to 26.63 dB cm-1 at 10 MHz. With solid glass sphere concentrations in the range of 0.025-0.9 w/w%, acoustic backscattering consistent with a wide range of ultrasonic appearances was achieved. Native gel wax maintained its integrity during compressive deformations up to 60%; its Young's modulus was 17.4  ±  1.4 kPa. The gel wax with additives was shaped by melting and pouring it into 3D printed moulds. Three different phantoms were constructed: a nerve and vessel phantom for peripheral nerve blocks, a heart atrium phantom, and a placental phantom for minimally-invasive fetal interventions. In the first, nerves and vessels were represented as hyperechoic and hypoechoic tubular structures, respectively, in a homogeneous background. The second phantom comprised atria derived from an MRI scan of a patient with an intervening septum and adjoining vena cavae. The third comprised the chorionic surface of a placenta with superficial fetal vessels derived from an image of a post-partum human placenta. Gel wax is a material with widely tuneable ultrasound properties and mechanical characteristics that are well suited for creating patient-specific ultrasound phantoms in several clinical disciplines.

AB - Here we describe methods for creating tissue-mimicking ultrasound phantoms based on patient anatomy using a soft material called gel wax. To recreate acoustically realistic tissue properties, two additives to gel wax were considered: paraffin wax to increase acoustic attenuation, and solid glass spheres to increase backscattering. The frequency dependence of ultrasound attenuation was well described with a power law over the measured range of 3-10 MHz. With the addition of paraffin wax in concentrations of 0 to 8 w/w%, attenuation varied from 0.72 to 2.91 dB cm-1 at 3 MHz and from 6.84 to 26.63 dB cm-1 at 10 MHz. With solid glass sphere concentrations in the range of 0.025-0.9 w/w%, acoustic backscattering consistent with a wide range of ultrasonic appearances was achieved. Native gel wax maintained its integrity during compressive deformations up to 60%; its Young's modulus was 17.4  ±  1.4 kPa. The gel wax with additives was shaped by melting and pouring it into 3D printed moulds. Three different phantoms were constructed: a nerve and vessel phantom for peripheral nerve blocks, a heart atrium phantom, and a placental phantom for minimally-invasive fetal interventions. In the first, nerves and vessels were represented as hyperechoic and hypoechoic tubular structures, respectively, in a homogeneous background. The second phantom comprised atria derived from an MRI scan of a patient with an intervening septum and adjoining vena cavae. The third comprised the chorionic surface of a placenta with superficial fetal vessels derived from an image of a post-partum human placenta. Gel wax is a material with widely tuneable ultrasound properties and mechanical characteristics that are well suited for creating patient-specific ultrasound phantoms in several clinical disciplines.

KW - 3D printing

KW - interventional procedures

KW - tissue mimicking materials

KW - ultrasound phantoms

UR - https://www.scopus.com/pages/publications/85040356421

U2 - 10.1088/1361-6560/aa9e2c

DO - 10.1088/1361-6560/aa9e2c

M3 - Article

C2 - 29186007

AN - SCOPUS:85040356421

SN - 0031-9155

VL - 63

JO - Physics in Medicine and Biology

JF - Physics in Medicine and Biology

IS - 1

M1 - 015033

ER -