Practical problems and solutions in spatially resolved spectroscopy

• Published in: Journal of magnetic resonance (1969) Vol. 79; no. 1; pp. 11 - 20
• Main Authors: Narayana, Ponnada A, Jensen, Dye J, Jackson, Edward F, Brey, William W
• Format: Journal Article
• Language: English
• Published: Orlando, FL Elsevier Inc 01.08.1988; Academic Press
• Subjects: Exact sciences and technology; Metrology, measurements and laboratory procedures; Physics; NMR spectrometry; Nuclear magnetic resonance; Nuclear magnetic resonance imaging; Spatial resolution
• ISSN: 0022-2364; 1557-8968
• DOI: 10.1016/0022-2364(88)90318-6

The practical problems in the implementation of the spatially resolved spectroscopy (SPARS) sequence have been addressed. Phantom studies have shown that the slice profile is distorted due to the spurious echoes and the phase shift induced by the settling gradient fields. Studies indicate that the spurious echoes arise because of the imperfect 180° refocusing pulse within the localization pulse train. It has been demonstrated that these echoes can be eliminated by the application of two orthogonal gradients around the 180° pulse. The phase shift introduced by the settling gradient fields has been compensated by phase shifting the selective 90° pulse with respect to the 180° refocusing pulse. It is shown that the spurious echoes do not significantly compromise the quality of the localized spectrum.