Polythermal image
A polythermal image showing Malon moving around on a Malon ship
A polythermal image was a type of imaging that could be done using a coherent neutrino beam.
In early 2375, Seven of Nine used coherent neutrino beams to scan the interior of a Malon freighter, determining that the Malon on board were constructing a shuttlecraft to steal the USS Voyager's multi-spatial probe from a gas giant. (VOY: "Extreme Risk")