Volume Selective Detection by Weighted Averaging of Constant Tip Angle Scans

We propose a method to improve the sensitivity in volume selective detection based on the CARVE excitation sequence (I. Serša and S. Macura, J. Magn. Reson. 135, 466-477 (1998)) which consists of signal acquisition with constant tip angle excitation and a short phase-encoding gradient pulse. Volume selectivity is achieved using the weighted average of a number of scans whose weights and gradient steps are determined by the shape of the excitation profile. The method is particularly useful for broadband volume selective detection of insensitive spins where the volume selection can be merged with the standard signal averaging process, without compromising the excitation bandwidth or Sensitivity.