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Ultrasound imaging is becoming a popular imaging technique that is a safe and painless alternative to Mammography 1p123 and other imaging procedures. Ultrasound uses sound waves to produce images from inside the body 2p1. Ultrasound imaging is sometimes referred to as sonography or ultrasound scanning. It requires the use of ultrasound gel, which is applied directly on the skin, and a small transducer. The probe acts as a transmitter which relays high-frequency sound waves 2p1. The gel acts as a conduit for the high-frequency sound waves to travel into the body. The resulting sound that bounces back is then gathered by the probe. Using these sound waves as data, an image is then generated by a computer 2p1. Ultrasound examinations are safe for the patient. Unlike x-rays, ultrasound imaging does not require the use of ionizing radiation. Real-time image capture via ultrasound enables the movement and inner workings of the body. Ultrasound imaging is non-invasive and can assist physicians in diagnosing medical conditions 2p1. Ultrasound imaging gives an image of the breast and its movement and structure.
Image 1. An ultrasound unit 2p2.
To gauge the level of blood flow in breast mass, a physician may use Doppler ultrasound techniques when performing an ultrasound examination of the breast. This is a special ultrasound technique that can analyze the blood flow that passes through blood vessels in major arteries and veins 2p1. Using this technique can sometimes yield extra data to determine the root cause of the mass.
Ultrasound imaging
Ascertain breast abnormality
The main objective of using breast ultrasound is to identify and diagnose abnormalities 2p1. These abnormalities are detected either through a physical exam (lump or discharge) or via breast magnetic resonance imaging (MRI) or a mammography 3p824. An abnormality can either be solid (tumor or lump) or fluid-filled (cyst) or a combination of both solid and cystic. Ultrasound imaging helps determine the state of the abnormality by displaying extra features of the area. Additionally, the rate of the blood flow in breast lesions is determined by the use of doppler ultrasound.
Additional Screening Method for Breast Cancer
Deaths due to breast cancer can be reduced via early 1p125. The only screening tool which is proven to be effective at this is mammography. However, not all forms of breast cancer can be detected with mammography. Some abnormalities are not noticeable with mammograms, especially in breasts that are dense 3p824. Breasts which are dense usually contain less fat and more fibrous tissue. Ultrasound and MRI can help detect breast cancer that may not be noticeable with mammography 2p1. MRI is more effective in detecting breast cancer but this option is sometimes not available to everyone due to the cost. If MRI is used for screening then ultrasound is not needed. However, abnormalities seen on MRI can still be diagnosed with ultrasound. Compared to both mammography and MRI, various abnormalities that need biopsy are detected when ultrasound is used 3p824. Usually these abnormalities are false positives (not cancer). Ultrasound is an ideal screening method for women who are not able to go for an MRI examination and at risk for breast cancer. Another example is pregnant women who are not able to go for a mammogram (due to x-ray exposure) 2p1.
Breast Biopsy Guided by Ultrasound
When a breast abnormality shows up in an ultrasound exam, an ultrasound-guided biopsy may be conducted. Ultrasound is commonly used to guide biopsy procedures because it dispenses real-time images. Usually, the ultrasound exam is conducted before the biopsy 2p3. The procedure and feasibility of this method can then be planned accordingly.
Prepare for an ultrasound
During the examination, a gown will be provided for patients to wear 2p4. Patients will need to undress from the waist up and remove all metal objects.
How is the ultrasound examination conducted?
Patients will be required to lie down with their back on the examining table 1p125. They will then be asked to raise their arms above their head. After that, the sonographer will apply the water-based ultrasound gel to the area of the body that needs examining. The gel’s function is to remove any air pockets that may reside between the transducer and the skin. Air pockets can interfere with the movement of sound waves 2p1. The gel also helps the transducer to firmly come into contact with the skin. The necessary image is then captured with the transducer by placing it on the body and moving it around the area that is being examined. There is no discomfort that is felt involving this procedure. However, if the area is tender, minor discomfort or pressure from the transducer is felt. If doppler sonography is required, the same transducer is used. The gel will be wiped off once ultrasound imaging is complete. Any remaining gel that is not wiped off will dry into powder form. No discoloration or staining is caused by the gel 2p1.
What happens during and after the ultrasound examination?
Patients experience little or no discomfort during an ultrasound examination 3p824. The entire procedure normally takes half an hour. A pulsating sound that changes in frequency may be heard if a doppler sonography is used to monitor blood flow 2p1. During the procedure, you may be required to change positions. Once the examination is complete, the ultrasound images are inspected. You may be asked to wait for the results while they are being reviewed. Normal activities can be resumed immediately after the ultrasound examination.
Interpretation of results
Patients can get the results of the examination from their primary care physician 2p5. The physician gets the results and a signed report from a radiologist who does the breast imaging and is responsible for interpreting the ultrasound images. Sometimes the radiologist will share the results with the patients after the examination. A follow-up exam is sometimes be necessary to further monitor any suspicious results or changes in a confirmed abnormality. This is the ideal method to determine the effectiveness of the treatment and if abnormality stabilizes over a period of time.
Benefits vs. risks
Benefits
Non-invasive scanning method (does not require the use of needles).
Little or no discomfort experienced.
Easily available, ease of use and less costly compared to other methods.
Extremely safe as it does not require the use of ionizing radiation
Soft tissues which does not display effectively on x-ray scans, show up clearly on ultrasound scanning.
Real-time imaging is possible with ultrasound. Minimally invasive methods such as fluid aspiration and needles biopsies benefit from this.
Lesions can be detected in women with dense breasts.
Detects and diagnose a breast lesion that cannot be scanned using mammography.
Determines areas of concern that are due to benign cysts or fat lobules
An ultrasound is used with a mammogram for women above the age of 30 3p826. For women below 30 years old, using ultrasound alone is enough to examine whether a biopsy is needed for an area of concern.
Risks
Following an ultrasound examination, further procedures such as biopsy or aspiration and follow-up ultrasound may be conducted. Usually areas of concern determined through ultrasound are found to be non-cancerous.
Limitations of ultrasound imaging
There are numerous types of cancer which do not show up on ultrasound.
Although ultrasound is one method used in breast imaging, it is not a replacement for clinical breast exams and mammography.
A biopsy may need to be further conducted to decide if a dubious abnormality is cancerous.
The majority of dubious abnormalities discovered through ultrasound are not cancers.
Some cancer signs only show up on mammograms and MRI and cannot be detected through ultrasound. One such example is calcifications which can only be determined through mammography.
Facilities that provide ultrasound imaging are limited.
Not all insurance plans cover ultrasound imaging.
A facility with radiologists that has expertise in breast imaging should be the most important factor when it comes to choosing where to do an ultrasound. This is because an effective ultrasound imaging depends on whether the radiologist is able to recognize any abnormality that may turn up during the scan, considering that it’s real-time imaging. A facility’s ACR accreditation status can determine a facility’s knowledge in ultrasound imaging. Please check the ACR accredited facilities database to locate the facilities in the area closest to you.
References
1. Chen P, Slanetza P. Incremental clinical value of ultrasound in men with mammographically confirmed gynecomastia. European Journal of Radiology; 83:123– 129. http://dx.doi.org/ 10.1016/j.ejrad.2013.09.021
2. American College of Radiology. Ultrasound. 2015; 1-5. Retrevied from http://www.radiologyinfo.org/en/info.cfm?pg=breastus
3. Shi X, Cheng H, Hua L, Jua W, Tian J. Detection and classification of masses in breast ultrasound images. Digital Signal Processing. 2010; 20:824–836. DOI:10.1016/j.dsp.2009.10.010.
