Ultrasound and sonogram are closely related terms, but they refer to slightly different things. An ultrasound is the test or technique that uses high-frequency sound waves to create pictures inside the body. A sonogram is the picture produced by that test. In everyday conversation, people and healthcare professionals often use the two words interchangeably, so they usually mean the same appointment.
If a healthcare professional recommends an ultrasound or tells you to schedule a sonogram, you generally do not need to look for two different tests. Both terms refer to the same type of medical imaging in everyday use. The main distinction is that ultrasound describes the imaging method or examination, while sonogram refers to the resulting image.
What is the difference between an ultrasound and a sonogram?
The difference is primarily in how the terms are used, rather than in the technology. Ultrasound imaging uses sound waves to create pictures of structures inside the body. The images produced by this process are called sonograms or ultrasound images.
According to MedlinePlus, ultrasound is also known as sonography or ultrasonography, and its images may be called sonograms. These terms overlap in clinical conversations, which is why a healthcare professional may use them to describe the same examination.
| Term | What it means | Example |
|---|---|---|
| Ultrasound | The imaging method or examination that uses high-frequency sound waves. | An abdominal ultrasound to examine internal organs. |
| Sonogram | The image created during an ultrasound examination. | A picture showing the appearance of an organ or a developing fetus. |
| Sonography | Another name for the ultrasound imaging technique. | Diagnostic sonography used to examine soft tissues. |
In practice, the distinction rarely changes what you need to do as a patient. If your appointment instructions say sonogram instead of ultrasound, check the specified body area and preparation instructions rather than assuming that a different procedure is required.
How does an ultrasound create a sonogram?
An ultrasound machine uses a small device called a transducer, often referred to as a probe. The probe sends high-frequency sound waves into the body and receives echoes that bounce back from internal structures. A computer processes those echoes to create images that appear on a screen, sometimes in real time.
During a typical external examination, the healthcare professional applies a water-based gel to the skin. The gel helps sound waves pass between the probe and the body. The probe is then moved over the area being examined to capture the required views. Cleveland Clinic describes ultrasound as a noninvasive imaging test that produces real-time pictures or video of internal organs and other soft tissues.
Not every ultrasound uses a probe on the outside of the body. Some examinations involve placing a specially designed probe inside a body opening to obtain images of particular organs. The technique selected depends on the area being examined and the information the healthcare professional needs.
What can an ultrasound or sonogram show?
Ultrasound examinations can help healthcare professionals examine different body structures and investigate specific medical questions. Depending on the type of examination, the images may show organs, soft tissues, blood vessels, or a developing fetus during pregnancy.
According to the American College of Radiology and Radiological Society of North America through RadiologyInfo, ultrasound has several uses, including examining internal organs, monitoring pregnancy, evaluating certain heart conditions, and guiding biopsies. The technique used depends on the body part and the reason for the examination.
Some common examples include:
- Abdominal ultrasound: Examines structures such as the liver, gallbladder, kidneys, and other abdominal organs.
- Pregnancy ultrasound: Provides images of the fetus and helps healthcare professionals assess development and other aspects of the pregnancy.
- Breast ultrasound: Examines breast tissue and may provide additional information about an area that needs evaluation.
- Doppler ultrasound: Evaluates blood flow by showing its direction and speed in certain blood vessels.
- Ultrasound-guided procedures: Helps a healthcare professional guide a needle during certain biopsies or other procedures.
A sonogram shows the information captured during the examination, but the image alone does not always establish what is causing a symptom or whether a particular condition is present. A healthcare professional interprets the findings in the context of the reason for the test and any other relevant information.
Is an ultrasound the same as an X-ray?
No. Ultrasound and X-rays use different technologies to create images. Ultrasound uses high-frequency sound waves, whereas conventional X-ray imaging uses ionizing radiation. Ultrasound does not use ionizing radiation, which is one reason it is commonly used in pregnancy and for examining many soft tissues.
The U.S. Food and Drug Administration (FDA) explains that ultrasound can produce real-time images of internal structures and blood flow without the ionizing radiation associated with X-rays. However, ultrasound is not the best examination for every medical question, and the appropriate imaging method depends on the body area and the information needed.
Ultrasound is generally considered safe when performed prudently by appropriately trained healthcare professionals. The FDA also notes that ultrasound energy can produce biological effects under some circumstances, so examinations should be performed for appropriate medical purposes rather than solely to obtain keepsake images or videos.
What should you expect during an ultrasound appointment?
The experience depends on the part of the body being examined. For many external ultrasounds, you lie on an examination table while a healthcare professional applies gel to your skin and moves a probe over the area. You may be asked to change position, hold your breath briefly, or remain still to help obtain useful images.
Some examinations require a fuller bladder, while others may require you to avoid eating or drinking for a specified period beforehand. Internal examinations may involve a specially designed probe inserted into the vagina or rectum, depending on the purpose of the scan.
The National Health Service (NHS) explains that preparation varies by examination and that an ultrasound appointment may involve an external or internal scan. Follow the instructions provided by your healthcare team, because preparation requirements for one type of ultrasound may not apply to another.
Does the difference matter when you receive your results?
Usually, the distinction between ultrasound and sonogram does not affect how your results are handled. The sonogram is the image, while the findings from the examination may also be documented in a report. Depending on the service and the reason for testing, a radiologist or another appropriately qualified healthcare professional may interpret the images and communicate the findings to the clinician who requested the examination.
If you receive a report, the wording may describe the images, note observations, or recommend additional evaluation when appropriate. Ask the healthcare professional who ordered the test to explain findings that are unclear and how they relate to your symptoms, medical history, or follow-up plan.
Which term should you use: ultrasound or sonogram?
Both terms are widely understood, and either may be used when discussing an appointment. Ultrasound is commonly used to describe the examination itself, while sonogram is more precise when referring to an image produced by the examination. Sonography and ultrasonography are also accepted terms for the imaging technique.
The key point is that an ultrasound and a sonogram are not usually two separate medical tests. If you are unsure what was ordered, confirm the type of examination and the body area with the healthcare provider or imaging center.