Evaluation of Selective Saturation and Refocousing Pulses in Chemical Shift NMR Imaging

  • Shin, Yong-Jin (Division of Physics & Chemistry, Chosun University) ;
  • Park, Young-Sik (Department of Marine Architecture & Ocean Engineering, Chosun University)
  • Published : 2000.02.01

Abstract

There are several methods to achieve selective NMR image of differing chemical species with the three most popular methods of Dixon's, CHESS, and SECSI. A major problem common to all chemical shift imaging methods is the uniformity of the static magnetic field and distortions introduced when RF coils are loaded with a conducting specimen. Without magnetic field shimming, these methods cannot be used to acquire selectively image protons in fat and water which are separated by approximately 3.0ppm. Experiments with a phantom, with linewidths of 2.5 to 3.5ppm, were quantitatively evaluated for the three methods and a new chemical shift imaging method. In this study the new chemical shift imaging method (modified CHESS+SECSI technique) which included a selective saturation and refocusing pulse, was developed to determine the ratios of water and fat in different samples.

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