Abstract
It aimed to explore the application value of high-frequency ultrasound image based on the wavelet bilateral filtering algorithm in the repair evaluation of hypertrophic scar and keloid, as well as the expression change of nerve growth factor (NGF). 72 patients with scars admitted to hospital from October 2018 to October 2019 were chosen and classified as hypertrophic scar patients (group A) and keloid patients (group B), with 36 cases in each group. All patients received scar repair treatment, and another 30 normal skin volunteers (group C) were selected. High-frequency ultrasound images based on the wavelet bilateral filter algorithm were utilized for skin examination. The expression differences of NGF and pro-NGF in each group were measured by immunohistochemical staining and Western blot. The results showed that the denoising effect (signal-to-noise ratio (PSNR) = 33.2762), structural similarity (SSIM = 0.8963), and edge similarity (FoM = 0.2975) of the proposed algorithm were better than those of bilateral filtering and wavelet soft-threshold algorithms. The skin thickness of groups A and B was considerably higher relative to that of group C ( P < 0.05), but the echo intensity of the skin dermis of groups A and B was evidently inferior to that of group C ( P < 0.05). The results of immunohistochemistry showed that in contrast to group C, the average optical density of NGF in groups A and B increased remarkably ( P < 0.01). In contrast to group C, the positive expression of pro-NGF in groups A and B was notably reduced ( P < 0.05). Western blot results showed that relative to group C, the expression of NGF protein in groups A and B was increased greatly ( P < 0.01), but the expression of pro-NGF protein in groups A and B was reduced ( P < 0.01). The results suggested that the wavelet bilateral filter algorithm can be adopted to evaluate pathological skin scars, and pathological skin scar formation was closely related to the expression levels of NGF and pro-NGF.
Highlights
It aimed to explore the application value of high-frequency ultrasound image based on the wavelet bilateral filtering algorithm in the repair evaluation of hypertrophic scar and keloid, as well as the expression change of nerve growth factor (NGF). 72 patients with scars admitted to hospital from October 2018 to October 2019 were chosen and classified as hypertrophic scar patients and keloid patients, with 36 cases in each group
Speckle noise has a greater impact on image quality. e wavelet transform denoising algorithm is a commonly used ultrasound image denoising algorithm [9], but it is very susceptible to changes in the noise frequency distribution, and speckle noise is still present in the low-frequency part. e bilateral filter can suppress the low-frequency domain noise, while effectively retaining the edge information of the ultrasound image [10]
Compared with bilateral filtering and wavelet soft-threshold, the peak signal-to-noise ratio (PSNR), SSIM, and FoM values of the proposed algorithm were all the largest, suggesting that the denoising effect, structural similarity, and edge similarity of the algorithm proposed in this work were favorable
Summary
Massive studies have shown that NGF plays a biological role in the production of pathological scars [5], but further research and verification are needed. With the rapid progression of medical imaging diagnostic technology, high-frequency ultrasound has become the main diagnosis tool due to its higher resolution and penetration rate, which is able to diagnose and distinguish the fine structure of the skin [7, 8]. 20 MHz high-frequency ultrasound is widely adopted in the diagnosis of skin lesions. It was applied to high-frequency ultrasound image processing to obtain high-quality images, to evaluate pathological skin scars, and to measure the expression changes of NGF and its pro-NGF, hoping to provide a theoretical basis for the diagnosis and prevention of pathological scars
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
