Effect of increased repetition time TR on precision of inversion-recovery T1 measurements

The effect of increased repetition time, TR, on the precision of inversion-recovery measurements of the spin-lattice relaxation time, T1, was calculated theoretically, simulated numerically, and measured experimentally. All three methods yielded similar results. With constant inversion times, the T1 precision was independent of TR. Therefore, 1) multiple-slice inversion-recovery fast-spin-echo T1 maps should be made one slice at a time, not with interleaved acquisition, and 2) once the longest inversion time ti has been set, TR should be set just enough longer than the longest ti to allow data acquisition.