Application of High-Frequency Ultrasound (48 MHz) in Imaging and Evaluating the Effectiveness of Microneedling in Reducing Striae Distensae—A Pilot Study

Background: Striae distensae (stretch marks) are atrophic skin lesions. Microneedling stimulates collagen remodeling, and high-frequency ultrasonography (HFUS) allows for the evaluation of these tissue changes. Objective: To assess the effectiveness of microneedling in reducing abdominal striae distensae using photographic and HFUS imaging. Methods: Ten women underwent three microneedling treatments at 6–8 week intervals. Skin structure was evaluated before and after the therapy using HFUS and photography. Results: Ultrasound imaging revealed pronounced structural tissue remodeling and a visible reduction in lesion visibility across the cohort. However, quantitative ultrasound shifts did not reach statistical significance in this pilot sample (n = 10), indicating that these findings represent observational trend data. In seven patients, a more homogeneous and ordered collagen structure was observed (increased medium echogenicity), while three showed the opposite trend. Visually, all subjects experienced shallower stretch marks, improved skin texture, evened color, and observational improvement. Conclusions: High-frequency ultrasonography suggests that microneedling is a safe and promising method for tissue remodeling and the clinical reduction of striae distensae.