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echogenicity : ウィキペディア英語版 | echogenicity
Echogenicity (misspelled sometimes as echogenecity) 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. 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. This is because microbubbles have a high degree of echogenicity. When gas bubbles are caught in an ultrasonic 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. 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.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「echogenicity」の詳細全文を読む
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