What is an ultrasound (sonography) imaging?
Diagnostic ultrasound (also known as sonography) is a diagnostic imaging method, operated by the transmission and receipt of sound waves to produce pictures of the inside of the body. It is used to view the heart, blood vessels, kidneys, liver, and other organs and internal body structures. At our clinic we use the latest ultrasound systems, providing distinct types of imaging in different parts of the body.
Why is an ultrasound imaging needed?
It can provide valuable information for diagnosing and treating a variety of diseases and conditions. It can help diagnose the causes of pain, swelling and infection in the body’s internal organs.
Ultrasound is the preferred imaging procedure for the diagnosis and monitoring of pregnant women to view the fetus.
What are the types of ultrasound imaging?
Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional ultrasound, that formats the sound wave data into 3-D images.
Most ultrasound examinations are done using a transducer on the surface of the skin, though sometimes doctors and assistants can get a better diagnostic image by inserting a special transducer inside the body.
As the technology has advanced, different types of ultrasound imaging have evolved:
- Doppler is a special application of ultrasound that measures the direction and speed of blood cells as they move through vessels.
- Bone sonography helps doctors diagnose osteoporosis.
- Echocardiograms are used to view the heart.
- 3D imaging adds another dimension to the ultrasound image, creating three-dimensional interpretations rather than the flat two-dimensional images that are made with traditional ultrasound.
- 4D ultrasounds show 3D images in motion.
What happens during an ultrasound imaging?
For most ultrasound exams, the patient is positioned lying face-up on an examination table. A warm water-based gel will be applied to the area of the body being studied. The gel will help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin that can block the sound waves. The radiologist or sonographer moves the transducer over the area being examined. If a Doppler ultrasound study is performed, you may actually hear pulse-like sounds that change in pitch as the blood flow is monitored and measured.
Most examinations are completed within 30 minutes, although more extensive exams may take up to an hour. The radiologist or sonographer – specifically trained to supervise and interpret the examination – will analyze the images and send a signed report to your primary care physician who will share the results with you.
How does ultrasound imaging work?
Ultrasound imaging involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe and are reflected back through tissue to varying degrees to the ultrasound transducer. A computer then uses those sound waves to create pictures of the inside of the body.
What are the benefits and risks of ultrasound imaging?
It has numerous benefits, particularly that the images are captured in real-time, so they can show the structure and movement of the body’s internal organs, as well as blood flowing through blood vessels. Ultrasound does not use ionizing radiation, so there is no radiation exposure. There are no known harmful side effects and there is virtually no discomfort during the test. Ultrasound examinations are a safe, non-invasive and painless procedure.
Ultrasound is also a good tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration. It is widely available, easy-to-use and less expensive than other imaging methods.
How should I prepare for an ultrasound imaging?
Preparation for the procedure will depend on the type of examination you will have. For some examinations your doctor may instruct you to fast for eight to twelve hours before your ultrasound, especially if your abdomen is being examined. Undigested food can block the sound waves, making it difficult to get a clear picture. For other examinations, you may be asked to drink a lot of water and to hold your urine so that your bladder is full when the scan begins for better visualization.
You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewelry in the area to be examined and you may be asked to wear a gown during the procedure.
What shall I do after the ultrasound imaging?
Ultrasound examinations are painless and easily tolerated. After an ultrasound examination, you should be able to resume your normal activities immediately.
Sometimes, follow-up examinations may be necessary because a suspicious or questionable finding needs clarification with additional views. Follow-up examinations are sometimes the best way to see if a treatment is working or if an abnormality is stable or changed over time.
What are the limitations of ultrasound imaging?
Some factors can affect image quality, including the presence of air (air-filled bowel or organs obscured by the bowel) and calcified areas in the body (bones, plaques and hardened arteries). The patient’s body size can also be an influential factor, because greater amounts of tissue attenuate (weaken) the sound waves as they pass deeper into the body.
Ultrasound has difficulty passing through the bone and, therefore, can only see the outer surface of bony structures and not what lies within (except in infants who have more cartilage in their skeletons than older children or adults). For visualizing internal structure of bones or certain joints, other imaging modalities such as MRI are typically used.
Although ultrasound is often used for diagnosis in order to prevent an invasive measure, sometimes it is unable to determine whether or not a mass is malignant, and a biopsy will be recommended which can also be performed at our clinic.