Finding out information about what is going on inside the body is a critical part of diagnosing disease and injury. One way to find out is to perform surgery to look directly inside the body. However, today we can obtain much of the same information without surgery by using of a variety of medical imaging techniques that show us pictures of the inside of our bodies.
X-ray imaging is the oldest and perhaps the most common medical imaging method. Others include magnetic resonance imaging (MRI), ultrasound imaging, computed tomography (CT), positron emission technology (PET), Electroencephalogram (EEG) and the use of digital camera technology.
The different imaging methods are suited to different tasks and are often complementary. X-ray based techniques such as X-ray film images and CT scans are based on the difference in the density of tissue and bone. MRI shows good image contrast between various soft tissues. Ultrasound can be done in real-time imaging to follow motion within the body.