Echogenicity
Encyclopedia
Echogenicity is the ability to bounce an echo, e.g. return the signal in ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

 examinations. In other words, Echogenicity is higher when the surface bouncing the sound echo reflects increased sound waves. It could be increased by intravenously administering gas-filled microbubble contrast agent to the systemic circulation. This is because microbubbles have a high degree of echogenicity. When gas bubbles are caught in an ultrasonic frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...

 field, they compress, oscillate, and reflect a characteristic echo- this generates the strong and unique sonogram in contrast-enhanced ultrasound. Gas cores can be composed of air, or heavy gases like perfluorocarbon, or nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 (Lindner, 2004). 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
Fatty liver
Fatty liver, also known as fatty liver disease , is a reversible condition where large vacuoles of triglyceride fat accumulate in liver cells via the process of steatosis...

 could cause increased echogenicity in the liver.

Women with polycystic ovary syndrome
Polycystic ovary syndrome
Polycystic ovary syndrome is one of the most common female endocrine disorders. PCOS is a complex, heterogeneous disorder of uncertain aetiology, but there is strong evidence that it can to a large degree be classified as a genetic disease....

may also show an increase in stromal echogenicity.
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