How Do Ultrasounds Work

How Do Ultrasounds Work?

An ultrasound scan uses high-frequency sound waves to create images of the inside of the body. It’s very good at looking at the soft tissues of the body and is often the first step in determining the cause for your symptoms. 

Also known as sonography, ultrasound imaging uses a small transducer (probe) to both transmit sound waves into the body and record the waves that echo back. Sound waves travel into the area being examined until they hit a boundary between tissues, such as between fluid and soft tissue, or soft tissue and bone. At these boundaries some of the sound waves are reflected back to the probe, while others travel further until they reach another boundary and are reflected back. Since the speed, direction, and distance sound waves travel differ depending on the boundary they run into, a computer can interpret this information as a two-dimensional image on a screen.


Ultrasound has a variety of uses, despite being most often associated with pregnancy. It can be ordered to investigate pain, swelling, or other symptoms.

For example, ultrasound can help determine the composition of lump, distinguishing between a cyst and a tumor. A cyst is a sac filled with fluid, which is mostly benign. A tumor is an area of complex tissue, which can be either benign or malignant. Ultrasound can usually help differentiate between benign and malignant tumors based on shape, location, and a number of other sonographic characteristics. Both cysts and tumors can be found in your skin, tissue, organs, and bones.

Ultrasound is a standard part of prenatal care, providing images of the fetus or embryo’s viability and growth.

In the abdomen ultrasound can help check for kidney stones, gallstones, liver disease, and the cause of stomach pain. Multiple still images are taken to represent the location, texture, and blood flow of each organ.  

Ultrasound is also very good at looking at cartilage, muscles, tendons, and ligaments to evaluate joints for fluid or inflammation. Called a musculoskeletal (MSK) ultrasound, these exams are often ordered for joint concerns such as symptoms in the ankle, elbow, knee, shoulder, or wrist. Again the dynamic nature of ultrasound is an advantage for accurate diagnosis, since we can evaluate the area in question while it’s moving and watch as a patient performs the action causing symptoms. MSK ultrasounds may be requested on their own or in conjunction with an X-ray to rule out a fracture.


To book an ultrasound, visit us at Medmo helps people schedule radiology imaging tests – such as MRI, CT scans, PET, and more – at nearby accredited centers and identify the payment solution that works best for them.


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