ABSTRACT
The management and evaluation of traumatic brain injury have been revolutionized with the advent of structural and, more recently, functional brain imaging. Computed tomography (CT) techniques were developed by the Nobel Prize-winning scientist Godfrey Hounsfield. The first CT imagers were developed by EMI Ltd. of Middlesex, England, and were introduced into clinical practice in 1972. These scanners came into the U.S. during approximately 1972-1973 and now have gone through five generations of development. CT is presently recognized as the first and most important step in evaluating for head and contiguous spine injuries following trauma.1 In 1946, Bloch and Purcell discovered that when atomic nuclei are placed in a magnetic field, certain properties of structures or tissues can be measured. These scientists received a Nobel Prize for their discoveries in 1952, and their work led to the use of magnetic resonance imaging (MRI) in humans in about 1983.2,3 MRI has been very much improved in its ability to be used for the evaluation of traumatic brain injury, and it is growing in adaptation in the acute care setting with the advent and refinement of fast imaging techniques and improvements in scanner hardware. The examination time for MRI is no longer a significant limitation in the evaluation of head trauma patients, as it is possible to obtain high-quality T1-weighted scans in 2 to 3 min using standard short repetition time/echo time (TR/TE) techniques.4
