A system for determining presence or absence of one or more thermally distinguishable objects in a living body is disclosed. The system comprises a combined image generator configured for combining non-thermographic three-dimensional data of a three-dimensional tissue region in the living body with thermographic two-dimensional data of the tissue region so as to generate three-dimensional temperature data associated with the three-dimensional tissue region. In a preferred embodiment the combined image generator comprises a computing device configured for calculating the location and/or orientation of the thermally distinguishable object in the three-dimensional tissue region, based on the three-dimensional temperature data.