I am particularly pleased to be able to write the introduction to this book that resulted from a collaborative effort by the Radiology Department, under the auspices of the Boerhaave Committee for Postgraduate Medical Education of the Faculty of Medicine, at the University of Leiden and the Department of Medical Imaging and Radiological Sciences at Vanderbilt University. Magnetic resonance imaging affords the opportunity to interrogate organ and system structure and function in a nondestructive manner without serious biological implications. Tissue contrast with this modality is exquisite and inherently superior to that of x-ray computed tomography. The advances to improve signal capture, development of rapid data acquisition techniques, fabrication of more appropriate pulse sequences, and availability of contrast agents portend increased versatility and specificity of these studies. Despite the proliferation of numerous general and specialized texts, the developments in MRI occur at such a pace that data in these references are necessarily dated. The technical horizon of MRI is vast with almost limitless possibilities of signal generation and plan reconstruction. Tissue contrast is so importantly affected by the coupling of signal generation and capture that collective experience of institutions and investigators is extremely important to the initiate and useful even to those individuals with the greatest clinical experience.