Application of High-Frequency Ultrasound to Evaluate Forehead Filling Materials.

BACKGROUND: In recent years, soft tissue materials have been applied as forehead fillers. Some filling materials need to be removed or refilled in a timely manner in certain situations; therefore, it is important to develop a method to identify the location and type of filling materials. This study summarizes the imaging findings of different filling materials under high-frequency ultrasound, providing a reference for clinical treatment. METHODS: We screened facial ultrasound images performed at the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences from April 2015 to July 2023 and classified and summarized the types of frontal filling materials and their imaging results. RESULTS: This study included ultrasound imaging results from 114 patients, including 39 with hyaluronic acid (HA) filling, 45 with polyacrylamide hydrogel (PAG) filling, 14 who received autologous fat transplantation, 2 who received prosthesis implantation, 2 who received both HA and PAG filling, and 12 who received silicone oil filling. HA mainly manifests as an anechoic zone on ultrasonography, with images divisible into four types. PAG primarily presents as fine punctate echoes, divisible into five types. Fat transplantation presents as a low-echo area with uneven density, divisible into five types. Finally, the silicone oil-filling material appears as a cloud-like high echo on the forehead, visible throughout the entire skin layer, and unclear imaging in deep tissues. CONCLUSION: High-frequency ultrasound is a safe and reliable method to evaluate the type and position of forehead filling materials, which can be easily applied in clinical practice. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Localization of the Submandibular Glands Using High-Frequency Ultrasound.

BACKGROUND: Injecting botulinum toxin (BTX) into the submandibular glands (SMGs) can treat drooling symptoms in neurological diseases and improve the aesthetics of SMG hypertrophy and ptotic SMGs. OBJECTIVES: This study aimed to define the size and position of the SMGs by high-frequency ultrasound, and to perform statistical analysis to improve the safety and accuracy of BTX injection therapy. METHODS: Neck ultrasonography with high-frequency ultrasound was performed on 214 volunteers. The length, height, and thickness of the SMGs, and the distance between the SMGs and the midline, the anterior border of the sternocleidomastoid, the mandible, and the surface were measured. RESULTS: The SMGs were almond-shaped with a mean [standard deviation] length of 33.7 [4.7] mm, a thickness of 13.3 [2.9] mm, and a height of 27.6 [6.0] mm. The length and height were significantly different between underage and youth groups. The size of the SMGs did not show any notable differences with increasing BMI; however, their depth, and the distance from the mandible, midline, and anterior border of the sternocleidomastoid increased. No significant differences were observed between the affected and healthy sides in patients with microtia, hemifacial microsomia, or cleft lip and palate. CONCLUSIONS: Ultrasound provides more comprehensive information regarding the size and position of the SMGs, which can serve as a reference in BTX therapy and in the diagnosis of SMG diseases involving size alterations.

High-Frequency Ultrasound Imaging Findings of Different Mental Injectable Soft Tissue Fillers.

BACKGROUND: In recent years, the use of mental injectable soft tissue fillers is popular. However, some fillers are difficult to distinguish from pathological tissue, and some non-absorbable fillers need to be removed in time. Therefore, identification of different fillers is important. In this study, we summarized the ultrasonic manifestations of different mental injectable soft tissue fillers to provide references for clinical practice. METHODS: We screened the mental ultrasound images from November 2014 to November 2021 in the Plastic Surgery Hospital of Chinese Academy of Medical Sciences, identified different filling injection materials, and summarized and classified the ultrasonic characteristics of each filling material. RESULTS: A total of 244 cases were included, involving 62 cases of hyaluronic acid, 126 cases of polyacrylamide hydrogel, 19 cases of growth factor, 16 cases of calcium hydroxyapatite, 15 cases of silicone oil and 6 cases of fat. The ultrasonic manifestation of hyaluronic acid was anechoic area, which could be divided into six types according to the distribution characteristics. The ultrasonography of polyacrylamide hydrogel showed fine punctate echo, which could be divided into nine types. The ultrasonographic appearance of growth factor was similar to the echo of the surrounding tissue, and the boundary was not clear. Calcium hydroxyapatite was characterized by uneven hyperechoic area, which was spread in the tissue space, with unclear boundary with surrounding tissues. Sonographic patterns of silicone oil were hyperechoic and cloudy on high-frequency ultrasound. The deep tissue and periosteum layer were not clear. Transplanted fat showed isoechoic area or uneven low-echo area, with clear boundary and peripheral adipose tissue acoustic enhancement. CONCLUSIONS: High-frequency ultrasound is safe and reliable for identification and typing of chin filling injection materials, which can be applied in clinical practice. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.