Correlation between 75 MHz high-frequency ultrasound and histopathology in psoriatic lesions

Background. High-frequency ultrasound (HFUS) at frequencies >20 MHz is a valuable non-invasive tool for high-resolution skin imaging, enabling quantitative assessment of epidermal and dermal morphology with an axial resolution of 21 μm. Such precision supports objective monitoring of dermatoses, including psoriasis. Objectives. To compare epidermal and dermal measurements of psoriatic lesions using 75 MHz HFUS and histopathology. Methods. Thirty psoriatic papules/plaques were imaged with 75 MHz HFUS (axial resolution: 21 μm) in patients who were referred for diagnostic biopsy, measuring epidermal thickness and subepidermal hypo-anechoic zone thickness. Lesions were marked for biopsy alignment, and histologic sections were evaluated along the same axis. Spearman’s correlation analyzed agreement between methods. Results. Mean epidermal thickness was 220 ± 33 μm (HFUS) vs. 215 ± 35 μm (histopathology; R = 0.82, p < 0.01). subepidermal hypo-anechoic zone thickness was 483 ± 97 μm (HFUS) vs. 448 ± 89 μm (histopathology; R = 0.88, p < 0.01). No significant inter-method differences were observed. Conclusion. 75 MHz HFUS correlates strongly with histopathology in measuring psoriatic epidermal and dermal inflammatory changes, supporting its use as a non-invasive tool for therapeutic monitoring.