Ultrasounds use high or low frequency sound waves to produce images of structures within your body. Most ultrasounds are performed using a sonar device outside of your body. However, some ultrasounds involve placing a device inside a natural opening in your body. Ultrasounds can be used for a variety of reasons, from diagnostic purposes to evaluating the growth and development of a fetus, to guiding needles used for cancer treatment. There are many different types of ultrasounds that will vary depending on what the ultrasound is being used for. Here are the most common types.
Transvaginal Ultrasound
This is a type of fetal ultrasound that involves inserting a wand-like transducer into the vagina where it will send out sound waves and gather reflections to create an image of the uterus, cervix, and fallopian tubes. Sometimes this type of ultrasound is used during the early stages of pregnancy, since the uterus and fallopian tubes are closer to the vagina than to the abdominal surface.
Transrectal Ultrasound
This type of ultrasound involves inserting a probe with a transducer attached into the rectum. Transrectal ultrasounds are most often used to check men’s prostate for any abnormalities that may indicate prostate cancer.
Transesophageal Echocardiogram
This is an alternative way to perform a procedure called an echocardiogram, which is used to diagnose or monitor heart disease. This is a type of ultrasound that is used to create an image of your heart by inserting a transducer into your esophagus. Because of the nature and location of this procedure, it usually requires sedation.
Transabdominal Ultrasound
This is an external ultrasound that involves applying gel to the abdomen before moving the transducer over the skin to create an image. This type of ultrasound is most often used during the later stages of pregnancy to evaluate the development and position of the fetus to make sure there are not any complications during the delivery. Transabdominal ultrasounds can sometimes also detect certain birth defects.
3D Ultrasound
Traditional ultrasounds are flat, two-dimensional images. 3D ultrasounds offer a type of technology that can provide three-dimensional images of a fetus with photo-quality details while it is still inside the uterus. This type of ultrasound is the most effective at detecting facial abnormalities or neural tube defects. Further, 4D ultrasounds are able to show 3D images of the baby in motion. 3D and 4D ultrasounds can also be used to create images of other parts of the body as well.
Doppler Ultrasound
A Doppler ultrasound is based on the Doppler effect, which looks at moving objects and can detect how fast it is moving by measuring the frequency of the echoes created by the sound waves. Doppler ultrasounds are mostly used to measure the rate of blood flow that is moving through the heart and other major arteries.