Optimization Of Scan Parameters For T-1-Flair Imaging At 1.5 And 3t Using Computer Simulation

Purpose: We attempted to optimize scan parameters for T-1-weighted fluid-attenuated inversion recovery (T-1-FLAIR) sequence at 3 and 1.5 tesla (T) using computer simulation.Methods: We measured the T-1 and T-2 relaxation time values (T(1)v and T(2)v) of gray (GM) and white matter (WM) at 3 and 1.5T, generated computer-simulated T-1-FLAIR (CS-T-1-FLAIR) images using those values, and compared the simulated and actual T-1-FLAIR images to verify the contrast reliability of our computer simulation. We mathematically and visually evaluated CS-T-1-FLAIR images at various repetition times (TR) and echo times (TB).Results: At 3T, the measured relaxation values for GM were T(1)v, 1524 ms, and T(2)v, 85 ms, and for WM, Tiv, 750 ms, and T(2)v, 65 ms. At 1.5T, the measured relaxation values for GM were Tiv, 1251 ms, and T2V, 99 ms, and for WM, Tiv, 623 ms, and T(2)v, 75 ms. Contrast of CS-T-1-FLAIR and actual T-1-FLAIR images was identical. An optimal TR of 3140 ms was determined for T-1-FLAIR at 3T and 2440 ms at 1.5T based on mathematical evaluation. The optimal TR ranges were 2400 to 3900 ms at 3T and 1800 to 3200 ms at 1.5T based on visual assessment of CS-T-1-FLAIR. A shorter TB provided better T-1 contrast.Conclusion: We optimized T-1-FLAIR by focusing on its most important scan parameters using computer simulations and determined that a longer TR was suitable at 3T than at 1.5T. Our computer simulation was useful for determining the optimal scan parameters.