text: Ultrasounds are actually the reading of digitized echos, like bats use to find objects in the dark. Or like sonar.\n\nAn "echo" in an ultrasound reading would be similar to a "shadow" in a photograph, and may mean nothing at all. If they told you to wait 3 months, there is almost definitely nothing to suggest a new cancer, but you can always ask the doc who ordered it to explain further.