ultrasound The introduction of high frequency ultrasound scanners has made it possible for non-invasive technology to be ušed in dermatology. It is possible to create an image of the skhťs structure by means of ultrasonic waves and computer technology, which is of use in research, diagnostics and follow-up examinations of therapeu-tic procedures. The sensitivity and scope of this methoďs possibilities depend firstly on the physical quality of the ultrasound waves and then on the technique ušed (especially scanners) and then on the characteristics and composition of the skin under observation, which significantly influences the spread of acoustic signál within the tissue. The more MHz the probe has, the more detailed the image we derive, but we gain lower depth. In dermatology the most commonly ušed probes háve a frequency of 20 MHz. This technique gained ground in investigation of oedemas and in wound healing, determining skin thickness, psoriasis therapy, sc-leroderma, and panniculitis. This application is important in melanomas and squamous-cell carcinomas. The differentiation of some structures such as nevi, sebaceous glands or hair follicles in difficult. A lot depends on the lateral and axial resolution of the device, so 50-100 MHz probes are ušed to study epidermal structu¬res, sebaceous glands etc. Our device (50 MHz) is mostly ušed in studying the electromagnetic and light fi-eld influence on skin as part of a wider research project.

        Key words: high frequency ultrasound, diagnostics, ultrasound use in dermatology.