Technological advances developed from our understanding of the electromagnetic spectrum, has provided medical technologists sophisticated tools with which to analyze and interpret bodily process 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, compute axial tomography, positron emission tomography and magnetic resonance imaging, are methods that can often provide clear diagnostic pictures without surgery. A magnetic resonance image (MRI) scan provides a view of bone, nerves and other soft tissues. The medical practitioner can view the MRI films and diagnose ailments such as a pinched nerve, a degenerative disc or a tumor. 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.