AN ADIABATIC MULTIPLE SPIN-ECHO PULSE SEQUENCE - REMOVAL OF SYSTEMATIC-ERRORS DUE TO PULSE IMPERFECTIONS AND OFF-RESONANCE EFFECTS

Application of AFP (adiabatic fast passage) pulses for removal of syst ematic errors associated with multiple spin-echo sequences is demonstr ated. The adiabatic fast passage pulses facilitate minimization of cum ulative pulse errors for all three components of magnetization. It is also shown that off-resonance effects present in conventional CPMG seq uences which degrade image quality in magnetic resonance imaging and i ntroduce systematic errors in measured T-2 relaxation time peak amplit udes can be suppressed by introduction of AFP pulses without any degra dation of overall signal intensity. The technique has been tested on t he N-15 spin-spin relaxation time measurements of a 110 amino acid dom ain of the F-actin cross-linking protein. (C) 1998 Academic Press.