Imaging Instruments

Where the instruments in the previous section listen to or sample the body directly, imaging instruments let a clinician actually see inside a living patient without surgery. Techniques such as EEG, X-ray radiography, ultrasound, CT, MRI and PET scanning each reveal a different kind of information - electrical activity, dense versus soft tissue, moving structures, three-dimensional anatomy, or metabolic activity - and together they allow diseases or defects to be detected at a very early stage, often before any clinical sym …