Apparatus for performing a medical procedure on a tissue within a body of a subject includes a wireless tag configured to be fixed to the tissue and adapted to emit radiation, thereby causing first signals to be generated indicative of a location of the tag in the body. An invasive medical tool includes a probe, which is adapted to penetrate into the body so as to reach the tissue. A handle is fixed proximally to the probe, for manipulation by an operator of the tool. A display, mounted on the handle, presents a visual indication to the operator of an orientation of the probe relative to the tag. A processing unit processes the first signals so as to determine coordinates of the tag relative to the probe, and drives the display responsive to the coordinates.