Hidradenitis suppurativa (HS) is a chronic, recurrent and often devastating disease with longterm evolution and severe psychological impact on patients. For practical management of patients as well as for pathogenetic research, skin imaging at a lesser magnification than used for histopathology may also be of interest. In vivo imaging in the millimetre range allows visualization of the hair follicle structure as well as the identification of associated inflammation and the spread of the disease into deeper tissues. This may be of considerable benefit to patients. When abscess and sinus tracts develop in the axillae, the ano-genital region or under the breasts, they may penetrate far from the skin, and may reach distant sites. If this is not properly identified before treatment the presence of such lesions may adversely affect the outcome of, for example, surgery. Similarly, appropriate visualization of the extent of all lesions may help in the planning of surgery; finally, non-invasive visualization of lesions may be used to monitor the effect of, for example, medical therapy. Imaging of this debilitating skin disease may therefore have broad positive consequences for the patients. Two methods have been used for the study of HS: high-frequency ultrasound and MR scanning.