Glossary of Terms

E

• Elastography

  A medical imaging technique that measures the elasticity or stiffness of a tissue. The technique captures snapshots of shear waves, a special type of sound wave, as they move through the tissue. The stiffness of the tissue gives information about the possible presence of disease. For example tumors are harder than the surrounding normal tissue and disease livers are stiffer than healthy ones.

• Electroencephalography (EEG)

  The recording of electrical activity along the scalp resulting from current flowing within the neurons of the brain. EEG can be used to diagnose epilepsy and other disorders associated with altered brain electrical activity.

• Electromagnetic Radiation

  A kind of radiation including visible light, radio waves, gamma rays, and x-rays, in which electric and magnetic fields vary simultaneously. The different forms are differentiated by their wavelength and energy. For instance, visible light has relatively long wavelengths and less energy compared to x-rays or gamma rays with short wavelengths and high energy.

• Electroporation

  Application of an external electrical field to increase the permeability of the cell membrane. It is usually used in molecular biology as a way of introducing some substance into a cell such as a drug, protein, or piece of DNA that can change the cell’s function.

• Endoscope

  A thin illuminated flexible or rigid tube-like optical system used to examine the interior of a hollow organ or body cavity by direct insertion. Instruments can be attached for biopsy and surgery. Similar technology is used in a laparoscope.

• Ex vivo

  A Latin phrase translating to "out of the living" that, in the medical sciences, refers to experiments conducted on tissues or organs that have been removed from a living organism.

• Exoskeleton

  The external skeleton that supports and protects an animal’s body in contrast to the bones of an internal skeleton. Rehabilitation engineers have used this design in nature to develop exoskeletons that attach to the outside of the body and assist individuals with functions like arm and leg movement.

• Extracellular Matrix (ECM)

  The ECM is a collection of extracellular molecules secreted by support cells that provides structural and biochemical support to the surrounding cells.

• Extracellular Vesicles

  Extracellular vesicles (EVs) are nanosized, membrane-bound vesicles released from cells that can transport cargo--including DNA, RNA, and proteins--between cells as a form of intercellular communication. For example, EVs released from healthy cells can carry DNA, RNA or proteins that help to direct repair of damaged tissues. EVs released from tumor cells can carry DNA, RNA, and proteins that act to help the tumor to metastasize to other tissues.