In this unprecedented era of revolutionary developments in clinical imaging, in no area of the body are dramatic breakthroughs better exemplified than in imaging of the heart. It is difficult for this writer to be objective about this work because he has watched its development in the exceptionally capable hands of a cardiovascular radiologist and a cardiovascular internist, functioning as an ideal amalgam in its preparation. In the process, the author of this Foreword has developed an unbounded enthusiasm for the content of the work. At the outset it must be stressed that the dramatic gains in the develop ment of new imaging modalities and the improvements in the old [e. g. , ul trasonography, echocardiography, radionuclides, computerized tomography (CT), cineradiography, magnetic resonance (MR)] have changed our concepts about the anatomy of a number of organ systems. Anatomy and even physiology virtually are being rewritten. These changes apply particularly to the chest (mediastinum), biliary tract, central nervous system (brain), heart and great vessels and the hemodynamics of the cardiovascular system. The authors have demonstrated in this exhaustive treatise how far our understand ing of the many cardiac abnormalities has progressed, made possible by the application of the new modalities and further advances in those already estab lished, particularly echocardiography and radioisotope scanning. These de velopments have altered and added significantly to our body of information, particularly in the many complex congenital anomalies and in coronary artery disease.