Non‐invasive evaluation of elasticity of skin with the processing of ultrasound images during ultraviolet radiation: An animal photoaging model

Abstract

Objective The aim of this study was to provide a non‐invasive imaging method to evaluate the physical and mechanical parameters as a novelty method during skin photoaging. Methods In order to evaluate the process of skin damage, 25 mice (C57BL6) were exposed to UVB radiation (0.03 mW/cm2), 5 times a week for 5 weeks. The thickness of the epidermal and dermal layers was measured weekly from the ultrasound images (40 MHz). The elastic parameters of the skin were estimated from the processing of the sequential ultrasound images with the motion detection algorithm during the injury generation process. Results The thickening, Young modulus, and shear modulus of the dermal and epidermal layers during the UVB damage process significantly increased during the 5‐week study period (P < .05). In addition, the percentage of changes in the thickness of the epidermal layer (0.22 ± 0.01 mm in day 0 to 0.37 ± 0.02 mm in day 35) and dermal layer (0.57 ± 0.05 mm in day 0 to 0.90 ± 0.08 mm in day 35) increased by 68% and 57%, respectively. Furthermore, Young modulus (154.41 ± 8.8 kPa) was 11 times more than that of non‐irradiated skin (14.90 ± 2.2 kPa) and the shear modulus (2.33 ± 0.04 kPa) was 2.2 times more than non‐irradiated skin (1.06 ± 0.04 kPa). Conclusion With processing the sequential ultrasound images and extracting the thickening, the elasticity of the skin layers can detect skin lesions by UVB radiation.

Elastic Modulus of Suboccipital Muscles, Cervical Range of Motion, and Forward Head Posture in Cervicogenic Headache

“…Based on the studies, applying compressive force and detecting changes in ultrasound images can be effective for evaluating biomechanical properties of the tissues such as stiffness [ 22 , 23 ]. Accordingly, in the present study, the following method was used for measuring elastic modulus:…”

“…The strain was determined by measuring the diameter of suboccipital muscles at two force levels (L1 and L2) using image J software according to the equation Strain = (L2-L1)/L1. Stress was determined based on the applied force (F) measured with a force gauge connected to the transducer via a retaining ring made of polylactic acid, according to the equation Stress = F2-F1/S (the area of the transducer) [ 22 , 23 ].…”

Light exposure and its applications in human health

“…For instance, UVB can induce keratinocyte and epidermal cell apoptosis, while UVA can affect cytochrome P450 (CYP450) activity and cell growth, leading to DNA damage and inflammatory responses [70]. Therefore, studying rat skin light models is crucial in exploring photosensitivity, skin inflammation, and neoplastic lesions [71][72][73][74][75]. The main types of human cells used in light studies are skin cells and fibroblasts.…”

Light exposure and its applications in human health

“…[107] Therefore, studying rat skin light models is crucial in exploring photosensitivity, skin inflammation, and neoplastic lesions. [108][109][110][111][112] In the future, we must continue to refine rat skin light models and apply them to various fields, including medicine, drug development, and cosmetology.…”

“…The mouse skin light model plays a crucial role in exploring skin inflammation, neoplastic lesions, immune response, and other related factors. [110,[113][114][115] This model has found extensive applications in life sciences, medical research, beauty, and other domains.…”