Technological advances developed from our understanding of the electromagnetic spectrum have provided medical technologists sophisticated tools with which to analyse and interpret bodily processes for diagnostic purposes. These methods are usually non-invasive processes for identifying and monitoring diseases or injuries of the body by using images representing internal anatomical structures and organs of the body. Ultrasound, computed axial tomography, positron emission tomography and magnetic resonance imaging are methods that can often provide clear diagnostic pictures without surgery. Perhaps the greatest advantage of each of these techniques is their ability to allow diagnosis without the need for surgery. Diagnostic imaging expands the knowledge of practitioners and the practice of medicine.