Deep body scan
A deep body scan was a medical imaging scan that went to the subatomic level.
In 2373, The Doctor set his holo-imager to take deep body scans of USS Voyager's crew. He had yet to scan Kathryn Janeway and said so, before revealing that he had discovered, via such a scan, that he'd performed complex neurosurgery Harry Kim, yet had no memory of having done so. (VOY: "Latent Image")