NMR proton imaging

A broad-based review of NMR imaging is presented from the viewpoint of one who has followed this new modality since its conception, but who has been working in the allied area of NMR blood flow measurement. Organizations working in NMR imaging throughout the world are identified, and clinical applications of several commercial systems are illustrated. The different pulse sequences currently used, as well as focused selective excitation are discussed in detail. Types of gradient fields as typified by Aberdeen's two-dimensional Fourier transform (2DFT) spin warp method, and Hammersmith Hospital's two-dimensional projection reconstruction (2DPR) method, are analyzed. Alternate magnet systems are compared, and arguments for the use of a permanent magnet structure are set forth. The principles and benefits of Mansfield's echo-planar technique are discussed. Finally, safety guidelines published by the Bureau of Radiological Health are stated and critically analyzed.