Nuclear magnetic resonance imaging using pulse sequences combining selective excitation and driven free precession

摘要

An improved nuclear magnetic resonance (NMR) imaging method using selective excitation in conjunction with driven free precession (DFP) to form two or three-dimensional images is disclosed. The combination of these techniques enables a plane section to be selected and subsequently reconstructed from multiple angle projections by known multiple angle reconstruction techniques such as are used in X-ray computed tomography. Alternatively the plane sections can be reconstructed using known Spin Warp or Fourier Transform Zeugmatography methods to produce a map of the spin density of the material, or a combination of spin density of the material, or a combination of spin density and relaxation times of the material in the selected plane. The improved imaging technique is particularly applicable to the detection and localization of various disease states of biological tissue which exhibit altered relaxation times.