MRI: a charmed past and an exciting future.

The invention and development of MRI took place under very desirable circumstances. Dr. Lauterbur, a distinguished NMR chemist, conceived of the basic idea. Once this concept was presented to the medical imaging community, a wonderful synergy developed between the two mature disciplines of NMR physical chemistry and medical imaging. This resulted in amazingly rapid progress and acceptance by the clinical community. This adventure is in sharp contrast to the history of x-ray imaging. This began with the accidental discovery of x-rays by Roentgen at the end of the 19th century. Unlike NMR, the basic x-ray mechanism was not understood and was mistakenly thought to not be an electromagnetic wave. MRI is now at an advanced stage where investigators study advanced hardware and software improvements. These studies include improved signal-to-noise ratio, resolution, and speed, which generally involve higher B(0). The high readout field results in numerous problems. These can be overcome by prepolarizing techniques using a high polarization field and a relatively low readout field.