Chemical-shift selective image

Fig. 1.26 I maging of 129Xe using (a) regular imaging and (b) chemical shift selective imaging sequence along the cross section of three NMR tubes containing toluene, water...

Fig. 7. Double spin-echo imaging sequence for chemical shift selective imaging. The sequence applies spectral-spatial excitation pulses as presented in Fig. 6. Refocusing is performed with standard slice selective 180° pulses. For the examples in Fig. 8 echo times were chosen to TEi = 20 ms and TE2 = 60 ms.

Another approach to water and fat selective imaging which is also based on chemical shift elfects should be mentioned here The so-called Dixon method works with phase shifts in asymmetric spin-echo versus symmetric spin-echo acquisition. This method was shown to provide high-quality chemical shift selective images even in the presence of an inhomogeneous magnetic field. However, extreme high sensitivity to only one component seems to be obtained more difficult. 

Pope et al. (1991) applied chemical-shift-selective imaging at microscopic resolution of various plant materials, including dried and undried fruits of fennel, to the study of selective imaging of aromatics and carbohydrates, water and oil. The non-invasive nature of the method gives it advantages over established methods of plant histochemistry, which involve sectioning and staining to reveal different chemical constituents. 

Spectroscopic and chemical-shift selective imaging of polymers... 

Fig. 10.3.2 [Hepl] Demonstration of chemical-shift selective imaging on a three-layer sandwich phantom from PTFE sheets, (a) Geometry of the phantom. The outer layers are ft om isotropic material the inner layer is from oriented material, (b) ID spin-density image.

Figure 5 (A) Full image of a polymer rod that has been immersed in a solvent mixture (isooctane, ethanol, toluene). (B,C) Chemical shift selected images of isooctane and toluene, respectively, showing the different degrees of penetration.

CHESS Chemical Shift Selective Imaging Sequence... 

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