foerfarande foer selektiv nmr avbildning av i kemiskt foeraendrad kaerna.

摘要

a method for providing NMR images free of chemical shift artifacts, obtained from selected nuclei of a sample containing nuclei having chemically-shifted NMR frequencies is described. Non-selected nuclei of the sample are selectively saturated prior to applying an NMR imaging sequence by applying to the sample an RF pulse containing frequencies equal to the chemically-shifted frequencies of the non-selected nuclei and having a narrow frequency spectrum about the chemically-shifted frequencies, Alternatively, selected nuclei are directly excited during application of an NMR imaging sequence by applying to the sample an RF pulse containing frequencies equal to the chemically-shifted frequencies of the selected nuclei, and having a a narrow frequency spectrum about the chemically-shifted frequencies so as to exclude signal contributions from the nonselected nuclei. These selective pulses are applied in the absence of the imaging magnetic field gradients.