A Tuned, 7-pulse Implementation of the Variable Power and Optimized Relaxations Delays

Motivation: In 1H MRS, higher efficiency of the water suppression is desirable. Goal(s): To develop an efficient water suppression method. Approach: Based on the variable power and optimized relaxations delays (VAPOR), all flip angles and inter-pulse delays of 7 radio frequency (RF) pulses were further tuned. Results: The spectra which acquired both a phantom (at 1.5 and 3 T) and a volunteer (at 3 T) demonstrated that the proposed implementation suppressed water signals efficiently. Simulation results also showed that the efficiency of the water suppression using the proposed VAPOR implementation was superior to that using existing implementations. Impact: The proposed implementation of the variable power and optimized relaxations delays (VAPOR) improved efficiency of the water suppression of MRS. The spectra acquired with the proposed implementation demonstrated the efficiency at 1.5 and 3 T.