the act or process of recording or producing an image, esp. by such means as radar, ultrasound, CT scan, etc. as for scientific research or medical diagnosis
See imaging in American Heritage Dictionary 4
noun
The visual representation of an object, such as a body part or celestial body, for the purpose of medical diagnosis or data collection, using any of a variety of usually computerized techniques, such as ultrasonography or spectroscopy.
Psychology The use of mental images to influence bodily processes and to control pain, or to achieve a goal that one has visualized or imagined.