Hydrogel based tissue mimicking phantom for in‐vitro ultrasound contrast agents studies

Abstract

Ultrasound medical imaging (UMI) is the most widely used image analysis technique, and often requires advanced in-vitro set up to perform morphological and functional investigations. These studies are based on contrast properties both related to tissue structure and injectable contrast agents (CA). In this work, we present a three-dimensional structure composed of two different hydrogels reassembly the microvascular network of a human tissue. This phantom was particularly suitable for the echocontrastographic measurements in human microvascular system. This phantom has been characterized to present the acoustic properties of an animal liver, that is, acoustic impedance (Z) and attenuation coefficient (AC), in UMI signal analysis in particular; the two different hydrogels have been selected to simulate the target organ and the acoustic properties of the vascular system. The two hydrogels were prepared starting from cellulose derivatives to simulating the target organ parenchyma and using a PEG-diacrylate to reproduce the vascular system. Moreover, harmonic analysis was performed on the hydrogel mimicking the liver parenchyma hydrogel to evaluate the ultrasound (US) distortion during echographic measurement. The phantom was employed in the characterization of an experimental US CA. Perfect agreement was found when comparing the hydrogel acoustical properties materials with the corresponding living reference tissues (i.e., vascular and parenchimal tissue).

Automatic image detection of Halloysite clay Nanotubes as a future ultrasound theranostic agent for tumoral cell targeting and treatment

“…To conduct the experiments, HNTs were dispersed in tissue mimicking gel samples, whose employment in the study of signal enhancement produced by solid nanoparticles have been already reported in literature [19][20][21][22]. In our case, the employment of an agarose gel was particularly suited to identify the specific HNT contribution to the backscatter amplitude with respect to the control, i.e.…”

Laser fluence and exposure time effects on optoacoustic signal from gold nanorods for enhanced medical imaging

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Echographic detectability of optoacoustic signals from low-concentration PEG-coated gold nanorods

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“…[45][46][47] After the mixing stage, an alkaline water solution of potassium hydroxide was added as a catalyst, and the resulting solution was poured into the phantom box, according to the following procedure. Before filling, the top of the box was sealed by means of a silicon layer, fabricated using a proper resin mold in turn realized by means of stereolithography, which presented four precisely positioned and shaped "bumps" (aimed at creating the corresponding solution housings directly into the hydrogel mass) and two circular stoppers (to close the lateral holes of the box).…”