@article {270,
	title = {Shimmed matching pulses: Simultaneous control of rf and static gradients for inhomogeneity correction},
	journal = {Journal of Chemical Physics},
	volume = {131},
	year = {2009},
	note = {J Chem Phys536HUTimes Cited:4Cited References Count:30},
	month = {Dec 21},
	abstract = {<p>Portable NMR systems generally suffer from poor field homogeneity and are therefore used more commonly for imaging and relaxation measurements rather than for spectroscopy. In recent years, various approaches have been proposed to increase the sample volume that is usable for spectroscopy. These include approaches based on manual shimming and those based on clever combinations of modulated radio frequency and gradient fields. However, this volume remains small and, therefore, of limited utility. We present improved pulses designed to correct for inhomogeneous dispersion across wide ranges of frequency offsets without eliminating chemical shift or spatial encoding. This method, based on the adiabatic double passage, combines the relatively larger corrections available from spatially matched rf gradients [C. Meriles , J. Magn. Reson. 164, 177 (2003)]. with the adjustable corrections available from time-modulated static field gradients [D. Topgaard , Proc. Natl. Acad. Sci. U.S.A. 101, 17576 (2004)]. We explain the origins of these corrections with a theoretical model that simplifies and expedites the design of the pulse waveforms. We also present a generalized method for evaluating and comparing pulses designed for inhomogeneity correction. Experiments validate this method and support simulations that offer new possibilities for significantly enhanced performance in portable environments.</p>
},
	keywords = {design},
	isbn = {0021-9606},
	doi = {Doi 10.1063/1.3243850},
	url = {<Go to ISI>://WOS:000273036300030},
	author = {Franck, J. M. and Demas, V. and Martin, R. W. and Bouchard, L. S. and Pines, A.}
}
@article {324,
	title = {"Shim pulses" for NMR spectroscopy and imaging},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {101},
	year = {2004},
	note = {P Natl Acad Sci USA882PTTimes Cited:38Cited References Count:16},
	month = {Dec 21},
	pages = {17576-17581},
	abstract = {<p>A way to use adiabatic radiofrequency pulses and modulated magnetic-field gradient pulses, together constituting a \&quot;shim pulse,\&quot; for NMR spectroscopy and imaging is demonstrated. These pulses capitalize on phase shifts derived from probe gradient coils to compensate for nonlinear intrinsic main magnetic field homogeneity for spectroscopy, as well as for deviations from linear gradients for imaging. This approach opens up the possibility of exploiting cheaper, less-than-perfect magnets and gradient coils for NMR applications.</p>
},
	keywords = {acquisition},
	isbn = {0027-8424},
	doi = {Doi 10.1073/Pnas.0408296102},
	url = {<Go to ISI>://WOS:000225951500004},
	author = {Topgaard, D. and Martin, R. W. and Sakellariou, D. and Meriles, C. A. and Pines, A.}
}
