An ultrasound tomography system with polyvinyl alcohol (PVA) moldings for coupling: in vivo results for 3-D pulse-echo imaging of the female breast

Abstract

Full-angle spatial compounding (FASC) is a concept for pulse-echo imaging using an ultrasound tomography (UST) system. With FASC, resolution is increased and speckles are suppressed by averaging pulse-echo data from 360°. In vivo investigations have already shown a great potential for 2-D FASC in the female breast as well as for finger-joint imaging. However, providing a small number of images of parallel cross-sectional planes with enhanced image quality is not sufficient for diagnosis. Therefore, volume data (3-D) is needed. For this purpose, we further developed our UST add-on system to automatically rotate a motorized array (3-D probe) around the object of investigation. Full integration of external motor and ultrasound electronics control in a custom-made program allows acquisition of 3-D pulse-echo RF datasets within 10 min. In case of breast cancer imaging, this concept also enables imaging of near-thorax tissue regions which cannot be achieved by 2-D FASC. Furthermore, moldings made of polyvinyl alcohol hydrogel (PVA-H) have been developed as a new acoustic coupling concept. It has a great potential to replace the water bath technique in UST, which is a critical concept with respect to clinical investigations. In this contribution, we present in vivo results for 3-D FASC applied to imaging a female breast which has been placed in a PVA-H molding during data acquisition. An algorithm is described to compensate time-of-flight and consider refraction at the water-PVA-H molding and molding-tissue interfaces. Therefore, the mean speed of sound (SOS) for the breast tissue is estimated with an image-based method. Our results show that the PVA-H molding concept is applicable and feasible and delivers good results. 3-D FASC is superior to 2-D FASC and provides 3-D volume data at increased image quality.

Spatial domain reconstruction for imaging speed-of-sound with pulse-echo ultrasound: simulation and in vivo study

“…Our proposed method uses measurements of observed echo phase delays between different lines of propagation, which thus uses pulse-echo measurements from singlesided tissue access, in contrast to transmission USCT, e. g. , with circular arrays (Duric et al 2010, Koch et al 2015 and to those techniques that require a passive reflector on the other side of the investigated tissue (Krueger et al 1998, Huang & Pai-Chi 2005, Sanabria & Goksel 2016. In contrast to other methods which use misregistration of ultrasound images when scanning the tissue from different angles (Krücker et al 2004, Shin et al 2010, Cho et al 2014, our proposed method utilizes the echo shift measurements, which is much more sensitive to sound-speed variations than use of the envelope (Jaeger et al 2015).…”

Multi-Perspective Ultrasound Imaging Technology of the Breast with Cylindrical Motion of Linear Arrays

“…Likewise, breast ultrasound relies heavily on the doctor's interpretation and is often used as a supplementary tool [13,14]. In general, biopsy is the gold standard for the diagnosis of breast cancer, which show that there are a lot of false-positive cases diagnosed by ultrasound imaging [15][16][17][18]. Ultrasound computer tomography (USCT) is a potential candidate for the imaging of breast cancer [19,20].…”

The Application of an Ultrasound Tomography Algorithm in a Novel Ring 3D Ultrasound Imaging System

“…One of the main advantages of the USCT system is the simultaneous recording of reflection, attenuation, and speed of sound images [ 8 , 9 ]. Additionally, high image quality and fast data acquisition can be achieved [ 10 ]. The patient is imaged in the prone position with the breast hanging freely into the imaging volume [ 11 ] so that the USCT images of the female breast are produced.…”