Ultra-High Frequency Ultrasound (UHFUS) Features of Pyoderma Gangrenosum, Venous Leg Ulcers, and Acute Ulcerative Lesions.

Pyoderma gangrenosum (PG) is a neutrophilic dermatological disorder, marked by the dysregulation of both innate and adaptive immunity. Recently, non-invasive imaging techniques, including the use of Ultra-High Frequency Ultrasound (UHFUS), have been used to assess patients with PG. The primary objective of this study is to characterize the UHFUS differences among various cutaneous ulcerative diseases. We enrolled 45 patients: 15 patients suffered from PG (Group 1), distinguished in inflammatory phase (PG-i) and non-inflammatory phase (PG-ni); 15 patients had Venous Leg Ulcers (VLU) (Group 2); and 15 patients had Acute Injury (AI) (Group 3). For each lesion, UHFUS examination was performed with a 70 MHz linear probe to examine the angle of ulceration, epidermal and dermal morphological characteristics vascular morphology and the "scattering" signal. The study identified significant differences in the ulceration angle among various ulcerative pathologies: obtuse in Group 2, flat or straight in Group 3, predominantly acute or straight in Group 1. Moreover, PG-i phase exhibited significant fragmentation of the dermoepidermal junction (DEJ). The presence of a Subepidermal Low Echogenic Band (SLEB), hypoechogenicity of the dermis, and fluid collections were predominantly observed in the PG-i. The predominant vascular morphology in Groups 2 and 3 was regular, while in Groups 1 was irregular, presenting a high degree of "scattering" signals. The study highlights the usefulness of UHFUS as an imaging tool for assessing skin ulcers, especially those related to PG. This approach could be promising for improving diagnosis and treatment. However, further research is needed for standardization and clinical implementation.