Elastography refers to medical imaging modalities that map the elastic properties and stiffness of soft tissue.
The cancer is much stiffer than the healthy tissue.
The most prominent techniques use ultrasound or magnetic resonance imaging (MRI).
Elastography can be used for additional diagnostic information compared to a mere anatomical image, and it can be used to guide biopsies or, increasingly, replace them entirely.
Elastography is completely noninvasive.
Elastography is used to investigate disease in the liver:
Liver stiffness is usually indicative of fibrosis or steatosis.
Elastography is used for detection and diagnosis of breast, thyroid, and prostate cancers.
Elastography are also suitable for musculoskeletal imaging, and they can determine the mechanical properties and state of muscles and tendons.
Magnetic resonance elastography is capable of assessing the stiffness of the brain.
Elastography has been used on transplanted kidneys to evaluate cortical fibrosis.
Elastography creates a distortion in the tissue.
It observes the tissue response to infer the mechanical properties of the tissue, and then displays the usually as an image.
Elastographic techniques use ultrasound, magnetic resonance imaging (MRI) and pressure/stress sensors in tactile imaging (TI) using tactile sensor(s).
There are many ultrasound elastographic techniques.
Acoustic radiation force impulse imaging uses ultrasound to create a qualitative 2-D map of tissue stiffness.
In shear-wave elasticity imaging a push is induced deep in the tissue by acoustic radiation force.
Supersonic shear imaging gives a quantitative, real-time two-dimensional map of tissue stiffness.
Supersonic shear imaging has demonstrated clinical benefit in breast, thyroid, liver, prostate, and musculoskeletal imaging.
Transient elastography gives a quantitative one-dimensional image of tissue stiffness.
This technique is used mainly by the Fibroscan system, which is used for liver assessment, to diagnose cirrhosis.
The liver stiffness is significantly higher in the cirrhotic liver.
Magnetic resonance elastography (MRE)
provides a quantitative 3-D map of the tissue stiffness, as well as a conventional 3-D MRI image.
Other techniques include elastography with optical coherence tomography, and tactile imaging.