Characterizing mechanical and medical imaging properties of polyvinyl chloride‐based tissue‐mimicking materials

Abstract

Polyvinyl chloride (PVC) is a commonly used tissue‐mimicking material (TMM) for phantom construction using 3D printing technology. PVC‐based TMMs consist of a mixture of PVC powder and dioctyl terephthalate as a softener. In order to allow the clinical use of a PVC‐based phantom use across CT and magnetic resonance imaging (MRI) imaging platforms, we evaluated the mechanical and physical imaging characteristics of ten PVC samples. The samples were made with different PVC‐softener ratios to optimize phantom bioequivalence with physiologic human tissue. Phantom imaging characteristics, including computed tomography (CT) number, MRI relaxation time, and mechanical properties (e.g., Poisson’s ratio and elastic modulus) were quantified. CT number varied over a range of approximately −10 to 110 HU. The relaxation times of the T1‐weighted and T2‐weighted images were 206.81 ± 17.50 and 20.22 ± 5.74 ms, respectively. Tensile testing was performed to evaluate mechanical properties on the three PVC samples that were closest to human tissue. The elastic moduli for these samples ranged 7.000–12.376 MPa, and Poisson’s ratios were 0.604–0.644. After physical and imaging characterization of the various PVC‐based phantoms, we successfully produced a bioequivalent phantom compatible with multimodal imaging platforms for machine calibration and image optimization/benchmarking. By combining PVC with 3D printing technologies, it is possible to construct imaging phantoms simulating human anatomies with tissue equivalency.

Investigation of PolyVinyl Chloride Plastisol Tissue-Mimicking Phantoms for MR- and Ultrasound-Elastography

“…The T 1 values (220-260 ms) found for plastisol at 1.5 T are lower than those of most soft tissues. These relaxation times are different than those reported in the literature in PVCP without cellulose addition [36,38], but direct comparison is not straightforward as measurement were performed at higher magnetic fields (3 and 7 T, respectively) on different PVCP. However, the objective of this study was to evaluate whether the studied PVCP is a good TMP candidate for typical MRE acquisition sequences, rather than to reproduce NMR relaxation times of biological soft tissues.…”

“…. These values are compared to T 1 and T 2 values from the literature measured in similar PVCP TMP (not containing cellulose) at 3 [38] and 7 T [36] (gray crosses).…”

“…Soft PVCP has been proposed in robotics as TMP for needle insertion [27,28], and also for Magnetic Resonance Elastography (MRE) [15,24,26,45,69,81,83,84], sonoelastography [26,29] and biomedical photoacoustic [30][31][32][33][34][35]. PVCP has been previously compared to silicone-based Ecoflex [24] and has been shown to be a very interesting candidate for MRE in terms of MRI and dynamic viscoelastic properties [36][37][38]. In addition to their relatively low cost, PVCP TMP are simple to prepare, stable over time at room temperature and resistant to damage caused by typical handling procedures.…”

Tissue mimicking materials for imaging and therapy phantoms: a review

“…4D CT has increasingly been used to define tumour motion in radiotherapy and is utilized in diagnostic radiology to investigate joint problems, the cardiac cycle and parathyroid washout of contrast. Increasingly, there is a desire to capture motion and deformation within CT and CBCT, and therefore materials with deformable properties are starting to be developed (Liao et al 2017, He et al 2019b. A description of dynamic anthropomorphic phantoms has been recently presented in a review by Bertholet et al (2019).…”

Diverse resourcing of Nerium indicum leaves for bio-utilization

“…A large number of chemical raw materials have been found in the ethanol extract of Nerium indicum leaves. Benzyl alcohol is used as preservative for ointment, fiber, nylon silk and plastic film desiccant, polyvinyl chloride stabilizer, photographic developer, cellulose acetate, ink, coating, paint [23]. Oleic acid is an organic chemical raw material used to make soap, lubricant, flotation agent, ointment and oleate, and also is a good solvent for fatty acids and oil-soluble substances [24].…”