Ultrasound technique to observe mechanical properties of tissue
Many diseases cause changes in the mechanical properties of tissues. Current imaging devices such as computed tomography (CT), ultrasound (US) and magnetic resonance imaging (MRI) are not directly capable of measuring these mechanical properties of soft tissue. Elastography as a straing imaging technique has been well established in the literature as a new imaging method. The straing distributions in tissues in response to an external compression are closely related to the distribution of tissue elasticity. These straing images can give a clear illustration of the underlying tissue stiffness which has been shown to provide useful clinical information.
In real-time elastography RF frames are acquired continuously and elastograms are generated in real-time by estimating the strain between sequential frames similarly to static methods. Fast algorithms are necessary in this kind of imaging. Strains between frames are small, thus the sensitivity of the algorithms is also very important.