A "Foreign Body" (FB) is any undesirable piece of solid matter (metal, glass, stone, plastic)

The purpose of this study was to observe sequential changes in rabbit liver under transmission electron microscopy after high-intensity focused ultrasound (HIFU) ablation. Thirty rabbits were randomly divided into 2 groups. The livers of rabbits in group A underwent single HIFU ablation; those in group B were given the ultrasound contrast agent Sonovue 0.2 mL/kg before HIFU exposure. Five rabbits from each of the 2 groups were killed at 0 h, 6 d, and 14 d after HIFU ablation. Tissue samples that included targeted and untargeted tissues were observed under transmission electron microscopy. Electron microscopy showed that most of the cell organs in targeted areas of groups A and B disappeared early after HIFU, but the basic cell structure was seen in group A. On the sixth day after HIFU ablation in the 2 groups, all cells in the targeted areas were disrupted and fibrous bands were detected in the rims of targeted areas. In surrounding areas, cell swelling in group B was more severe than in group A, and a greater number of apoptotic bodies were found in group B. The use of an ultrasound contrast agent can enhance the effects of HIFU ablation on the destruction of cell ultrastructure and can enlarge the region of HIFU ablation; this provides experimental evidence for control of HIFU effects.

The aim of this study is to assess the physical damage of cavitation effects induced by low frequency ultrasound and microbubbles (MBs) to an in vitro vessel. A rabbit carotid artery filled with SonoVue MBs and methylene blue was irradiated with 20-kHz ultrasound, and the results were recorded by high-speed photography at 3000 frames per second. The carotid artery filled with MBs experienced a slight tremor during ultrasonication. Six intermittent blue flow events occurred in two places on the artery wall during the 5-s process. The duration of each leakage event was 90-360ms with an average of 200ms. Hematoxylin-eosin (H-E) staining demonstrated the separation of the carotid artery elastic membrane, local blood vessel wall defects and hole formation, and the surface of the ruptured area was rough and irregular. Another carotid artery was filled with a 0.9% NaCl solution and methylene blue as a control and irradiated with 20-kHz ultrasound. No blue liquid flow was seen, and no holes in the vessel were observed. H-E staining revealed intact vascular endothelial cells and smooth muscles with no vascular wall defects. Low-frequency ultrasound combined with MBs can cause a vessel to rupture and holes to form in a short time. High-speed photography is useful for observing transient changes caused by the effects of ultrasound cavitation on an in vitro vessel.

Quantitative and multiparametric blood analysis is of great clinical importance in cardiovascular disease diagnosis. Current blood analysis methods are typically restricted to invasiveness, bulky instruments and complicated clinical procedures. Wearable devices can realize on-skin assessment of several vital signals but generally exhibit very limited blood analyzing functions. Here, we report a flexible optoacoustic blood stethoscope (OBS) for multiparametric cardiovascular monitoring, bypassing the need for invasive procedures. The device features the light delivery elements for blood illumination and the piezoelectric acoustic elements capable of capturing the light-induced acoustic waves. This flexible device can adhere to the skin for continuous and non-invasive in-situ monitoring of multiple cardiovascular biomarkers, including hypoxia, drug concentration decay, and hemodynamics, which can be further visualized with the tailored 3D algorithm. Demonstrations on both in-vivo animal trials and human subjects highlight the OBS's unique potential to provide a new avenue for cardiovascular disease diagnosis and prediction.