This is plotted in Fig. , for both optimal sensitivity (α = 1) and constant noise (α = 2) NUWS schemes. The function increases for large resolution enhancements, indicating a practical if not theoretical limit to the approach. Equally however, linewidths may be significantly reduced, by 4.6-fold or 2.8-fold (α = 1 or 2 respectively), with a ten-fold increase in acquisition time, which is entirely practical when rapid longitudinal relaxation optimised SOFAST or BEST experiments are employed .