Ultrasound is an imaging technique that uses sound waves to create a picture of what’s going on inside your body. The images produced by ultrasound are not always black and white. Instead, they can appear in a range of shades of gray.
If a mass appears darker gray than surrounding tissue in an ultrasound, it is considered hypoechoic. If a mass appears brighter, it’s considered hyperechoic.
In this article, we’ll explore the differences between hypoechoic and hyperechoic masses and what these findings might mean for your health.
How Ultrasound Works: A Quick Primer
Before we dig into the specifics of hypoechoic vs. hyperechoic, let’s zoom out and discuss how ultrasound works.
Sound Waves and Image Creation
Ultrasound machines send high-frequency sound waves into the body. These waves bounce off your tissues, and the ultrasound machine then picks up these echoes and turns them into an image. Tissues that are denser reflect more sound waves.
Echogenicity and Tissue Density
Echogenicity is the term doctors use to refer to a tissue’s ability to reflect sound waves. Tissues that are highly echogenic appear as bright spots on the ultrasound image. Tissues with low echogenicity appear darker.
Anechoic structures, such as urine, appear black on an ultrasound because they don’t reflect any sound waves.
Hypoechoic Masses: What They Are and What They Mean
On an ultrasound, hypoechoic masses appear darker than the tissue around them. This darkness suggests that the tissue is relatively dense.
Hypoechoic tissues include solid tumors and some kinds of inflammation.
What it might mean for you
Hypoechoic results can be associated with both harmless and cancerous conditions, so more testing is usually needed to figure out what’s going on.
Factors like the size and shape of the mass, as well as whether there are calcifications or not, can make doctors more or less suspicious of cancer. Larger hypoechoic nodules with calcifications tend to be more likely to be cancerous.
Here are some examples of hypoechoic masses in specific areas of the body:
- Breast: Could be a fibroadenoma or cancerous tumor
- Thyroid: Nodules are common, but a small number are cancerous
- Uterus: Could be a fibroid
Hyperechoic Masses: What They Are and What They Mean
In ultrasound imaging, hyperechoic masses show up as brighter than the tissues around them. This usually means the tissue is relatively dense, or that it’s composed of materials that reflect sound waves well.
Fat, calcium deposits, and air are all hyperechoic.
Whether a hyperechoic finding is cause for concern depends on the circumstances. Both benign and malignant conditions can have hyperechoic qualities.
For example, lipomas (fatty, noncancerous tumors) are often hyperechoic. Calcifications, or areas of hardened calcium, within tumors are also hyperechoic.
In the liver, hyperechoic lesions might turn out to be hemangiomas, which are benign vascular tumors. In the kidney, hyperechoic areas can be angiomyolipomas, or benign tumors that contain fat, muscle, and blood vessels.
Benign vs. Malignant Masses: What’s the difference?
Ultrasound can help doctors tell the difference between tumors that are unlikely to cause harm (benign) and those that are likely to be dangerous (malignant).
Benign tumors usually have defined borders and don’t invade other organs. Malignant tumors may have irregular shapes and invade surrounding tissues.
Doppler ultrasound can also show blood flow within the mass. A lot of blood flow can mean a tumor is malignant.
Keep in mind that doctors often need to biopsy a mass to know for sure.
Frequently Asked Questions
Is hypoechoic a tumor?
Not necessarily. A hypoechoic finding simply means that an area on an ultrasound appears darker than the surrounding tissue. While some tumors can be hypoechoic, so can many benign conditions like cysts, inflammation, or even normal tissue variations. Further investigation, like a biopsy, is often needed to determine the exact cause and whether it’s cancerous.
Should hypoechoic nodules be removed?
It depends. The decision to remove a hypoechoic nodule is based on several factors, including its size, shape, location, growth pattern, and the presence of any suspicious features. If the nodule is small, stable, and doesn’t show any concerning characteristics, your doctor may recommend monitoring it with regular ultrasounds. If there’s a risk of cancer or if the nodule is causing symptoms, removal or biopsy might be necessary.
What tissue is hyperechoic?
Hyperechoic tissue appears brighter on an ultrasound image because it reflects more sound waves than surrounding tissues. Examples of hyperechoic tissues include bone, fat, and fibrous tissue. Air also reflects sound waves strongly, making it appear hyperechoic. The appearance of tissue on an ultrasound is relative, so a tissue can be hyperechoic compared to one tissue and hypoechoic compared to another.
Conclusion
Hypoechoic masses appear darker on an ultrasound image, suggesting they’re denser, while hyperechoic masses are brighter, indicating they reflect more sound waves. Both types can be either harmless or cancerous.
Ultrasound is a useful tool that helps doctors find and understand masses inside the body.
If an ultrasound shows a hypoechoic or hyperechoic mass, be sure to discuss the results with your doctor. You might need more tests to find out what’s causing the finding.