Investigation of foreign objects in soft-tissue using a PE-CMOS ultrasound system: a preliminary comparative study

Abstract

In this study, we have tested the ability of four imaging modalities to investigate foreign objects in soft tissue. We inserted wood, plastic, glass, and aluminum objects into a pork sample to simulate traumatized soft tissue. Each object was inserted into the skin, then passed through the fat tissue layer and penetrated into the muscle layer. We then took images of the pork sample using four different modalities:(1) a C-Scan imaging prototype which consists of an unfocused transducer, a compound acoustic lens, and a 2D ultrasound sensor array based on the piezoelectric sensing complementary metal-oxide semiconductor (PE-CMOS) technology; (2) a portable B-Scan ultrasound system; (3) a conventional X-ray system; (4) and a computed radiography (CR) X-ray system. We found that the aluminum and glass objects were clearly visible in both conventional X-ray and CR X-ray images with good contrast-to-noise ratio (CNR); however, the wood and plastic objects could not be clearly seen using these modalities. However, we found that the wood, plastic, and glass objects, as well as the thicker aluminum object, were clearly visible in the C-Scan ultrasound images. Furthermore, the fold fibro structures of the fat and muscle tissues in the pork were observable using this modality. The C-Scan prototype images produce neither speckle nor geometry distortion. Both of these issues are commonly seen in B-Scan ultrasound. The results of this study also indicate that the C-Scan images have better CNRs for most foreign objects when compared to other imaging modalities.