T-1 imaging using phase acquisition of composite echoes

A new magnetic resonance method for T-1 imaging is presented. It is based o n the simultaneous acquisition of a spin echo and a phase-shifted, stimulat ed echo. The phase of this composite echo image is modulated heavily by the spin-lattice relaxation time T-1, whereas spin density and T-2 do not infl uence the phase information. This phase information can be assigned easily to corresponding T-1 values. Although this method is sensitive to radiofreq uency inhomogenities, phantom studies showed that high precision and reason able accuracy of T-1 determination can be achieved. Moreover, this method w as found to be very robust, because no fitting is required. T-1 imaging of the human brain was performed to confirm the in vivo utility of this method . (C) 1999 Wiley-Liss, Inc.