Imaging of melanoma: usefulness of ultrasonography before and after contrast injection for diagnosis and early evaluation of treatment.

High-frequency ultrasound (8-14 MHz) is routinely used to display cutaneous melanomas. Maximum thickness measurement (Breslow index) has been shown to be well correlated to histologic findings for lesions of more than 0.75 mm. Some morphological criteria (strong delineation, hypoechoic texture, homogeneity) have been reported to help differentiate between malignant and benign pigmented blue lesions, but remain insufficient. Vascular ultrasound analysis using Doppler mode provides additional information and showed good specificity for malignancy (90%-100%), but variable sensitivity (34%-100%). Recent advances in ultrasound imaging allow functional evaluation. Likewise, dynamic contrast-enhanced ultrasound using contrast medium injection and specific perfusion and quantification software showed promising results in clinical and preclinical trials for early prediction of tumor response to target treatments.