Some patients are anxious when referred for an unfamiliar study or procedure and sharing some basic information about what to expect during their ultrasound study may help reduce some of their concerns. Sonography uses sound waves to create internal images of the body. The above video is an ultrasound image of a beating heart. The red and blue images appear because of the different sound waves produced when blood flows toward or away from the transducer as the test is performed. Ultrasound doppler is similar to the sense of echolocation used by dolphins and bats to locate objects.
While ultrasound technology is a painless non-invasive procedure, some test do require special preparation to obtain accurate readings.