Application of high‐frequency ultrasound in detection and identification of nasal filling injection materials

Objective To access and determine the ultrasound images of different nasal filling injection materials. Methods From November 2014 to November 2021, facial ultrasound images of Plastic Surgery Hospital of Chinese Academy of Medical Science were analyzed and judged. Results A total of 337 cases were enrolled, including 203 cases of hyaluronic acid, 102 cases of polyacrylamide hydrogel, 16 cases of calcium hydroxyapatite‐based fillers, 10 cases of silicone oil, and 6 cases of growth factor. According to ultrasound images, hyaluronic acid is characterized by anechoic area with a clear boundary, which seems like a capsule, and the internal echo is uniform, there is no obvious blood flow signal in it. It is possible to see a stratified appearance if hyaluronic acid diffused into surrounding tissues, and it is mainly exhibited as hypoechoic area, with anechoic or hypoechoic areas in it. Polyacrylamide hydrogel showed irregular flocculent hypoechoic or fine punctured hypoechoic under ultrasound, which could aggregate into cystic hypoechoic area or disperse in tissue space, and echo floating or dislocation flow could be seen under probe pressure. Under ultrasound, calcium hydroxyapatite‐based filler is characterized by heterogeneous hyperechoic or hypoechoic area, which spreads in the tissue space with unclear boundary with surrounding tissue, and no obvious liquid flow could be observed. Silicone oil is commonly found in the dermis, it is characterized by cloud‐like high echo, the deep tissue is not clear. Growth factor is characterized by heterogeneous echo, which is similar to the echo of peripheral tissue, and the boundary is not clear. Plenty of blood flow signals suggest infection. If the image is characterized with posterior echogenic shadow, it suggests calcification. Conclusions High‐frequency ultrasound can identify the types of nasal filling injection materials and can guide the selection of clinical treatment plan according to the classification of imaging features.