A medical imaging system for identifying a target structure (TS), e.g. a tumor, in a biological tissue. A hyperspectral camera system is used for imaging a surface area (A1) of the tissue (BT), e.g. with a limited spectral resolution, but enough to allow identification of suspicious areas where the target structure (TS) may be, e.g. such areas can be visually indicated on a display to the operator. A probe (PR), e.g. an optical surface probe, is used to provide probe measurement of a smaller surface area (A2) of the tissue, but with more information indicative of the target structure. The probe is selected to provide a higher specificity with respect to identification of the target structure than the hyperspectral camera (HSC). The hyperspectral processing algorithm (PP) is then calibrated based on probe measurement data performed within the suspicious areas, thus providing a calibrated hyperspectral processing algorithm resulting in images with an enhanced sensitivity to identify the target structure. Only few probe measurements are required to significantly improve the resulting image, thereby providing a reliable and fast target structure (TS) identification.