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Echogenicity (misspelled sometimes as echogenecity) or echogeneity is the ability to bounce an echo, e.g. return the signal in ultrasound examinations. In other words, echogenicity is higher when the surface bouncing the sound echo reflects increased sound waves. Tissues that have higher echogenicity are called "hyperechogenic" and are usually represented with lighter colors on images in
medical ultrasonography Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscle ...
. In contrast, tissues with lower echogenicity are called "hypoechogenic" and are usually represented with darker colors. Areas that lack echogenicity are called "anechogenic" and are usually displayed as completely dark.


Microbubbles

Echogenicity can be increased by intravenously administering gas-filled microbubble contrast agent to the systemic circulation, with the procedure being called
contrast-enhanced ultrasound Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast medium to traditional medical sonography. Ultrasound contrast agents rely on the different ways in which sound waves are reflected from interfaces between substances. T ...
. This is because microbubbles have a high degree of echogenicity. When gas bubbles are caught in an ultrasonic frequency field, they
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,
oscillate Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
, and reflect a characteristic echo- this generates the strong and unique sonogram in contrast-enhanced ultrasound. Gas cores can be composed of
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, or heavy gases like perfluorocarbon, or nitrogen. Heavy gases are less water-soluble so they are less likely to leak out from the microbubble to impair echogenicity (McCulloch ''et al.'', 2000). Therefore, microbubbles with heavy gas cores are likely to last longer in circulation.


Reasons for higher echogenicity

During ultrasound examinations, sometimes echogenicity is higher in certain parts of body. Fatty liver could cause increased echogenicity in the liver, especially if the liver transaminases are elevated. Women with
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may also show an increase in stromal echogenicity.


See also

*
Contrast-enhanced ultrasound Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast medium to traditional medical sonography. Ultrasound contrast agents rely on the different ways in which sound waves are reflected from interfaces between substances. T ...
*
Echogenic intracardiac focus Echogenic intracardiac focus (EIF) is a small bright spot seen in the baby's heart on an ultrasound exam. This is thought to represent mineralization, or small deposits of calcium, in the muscle of the heart. EIFs are found in about 3–5% of nor ...
* Ultrasound


References

{{reflist Hearing Acoustics Ultrasound Medical physics Medical ultrasonography