Often, the terms sonogram and ultrasound are used interchangeably. However, there’s a difference between the two:
- An ultrasound is a tool used to take a picture.
- A sonogram is the picture that the ultrasound generates.
- Sonography is the use of an ultrasound tool for diagnostic purposes.
In short, an ultrasound is the process, while a sonogram is the end result.
Sonography is a noninvasive, painless procedure. It uses high-frequency sound waves — called ultrasound waves —to produce images of organs, soft tissues, blood vessels, and blood flow, from inside the body. These images are used for medical analysis.
After x-ray exams, ultrasound is the most commonly used form of diagnostic imaging. It helps doctors gain insights into the inner workings of the body, and is known for being:
- radiation free
- widely accessible
A sonogram (also called an ultrasonogram) is the visual image produced during an ultrasound examination.
A medical sonographer — often referred to as an ultrasound tech — is the person trained to use ultrasound diagnostic imaging technology (sonography). They provide doctors with detailed images of what’s going on inside of patients.
Ultrasounds use high-frequency sound waves that are beamed into the body and bounce back (echo) off tissue and organs. These echoes generate electrical signals that are translated by a computer to produce images of the tissues and organs.
Variations of ultrasound include:
- Doppler ultrasound can be used to measure and visualize blood flow in the heart and blood vessels.
- Elastography is used to differentiate tumors from healthy tissue.
- Bone sonography is used to determine bone density.
- Therapeutic ultrasound is used to heat or break up tissue.
- High intensity focused ultrasound (HIFU) has been designed to destroy or modify abnormal tissue in the body without opening the skin.
Most ultrasounds are done using a transducer on the surface of the skin. At times, a better diagnostic image can be generated with the insertion of a special transducer into one of the body’s natural openings:
- Transvaginal ultrasound uses a transducer wand that is placed in a woman’s vagina to get images of her uterus and ovaries.
- Transrectal ultrasound, sometimes used in the diagnosis of prostate conditions, uses a transducer wand that is placed in the rectum.
- Transesophageal echocardiogram uses a transducer probe in the esophagus to get images of the heart
Probably best known for confirming and monitoring pregnancy, ultrasound is also commonly used by doctors for:
Doctors use ultrasound imaging to help diagnose conditions affecting the organs and soft tissues of the body, including:
- blood vessels
There are some diagnostic limitations for ultrasounds. For example, sound waves do not transmit well through areas that might hold gas or air (such as intestines), or areas blocked by dense bone.
When a doctor needs to remove tissue from a very precise area in the body — such as in a needle biopsy — ultrasound imaging can help with visual direction.
Ultrasound is sometimes used in the detection and treatment of certain soft-tissue injuries.
Although often used interchangeably, ultrasound is the procedure of using sound waves to create images from inside the body. Sonogram is the image produced by an ultrasound examination.
Ultrasound is considered a safe and affordable imaging technology to help a doctor make a diagnosis regarding soft tissue and organs in the body.