2013 年 69 巻 4 号 p. 380-385
This study focuses on optimization of the flip angle (FA) of phase-sensitive inversion recovery (PSIR) reconstruction (PSIR-FA) to achieve improved tissue contrast. Intensity normalization removes the larger variations in image intensity caused by falloff, thus improving the visualization of tissue contrast. We evaluated tissue contrast for images in healthy volunteers using the phantom influence of T1 relaxation and FA. T1 relaxation is improved due to the T1* effect and enables a high PSIR-FA to be set. The contrast-to-noise ratio (CNR) of the PSIR-FA 20° image is good, since magnetization is almost fully restored to normal. The usefulness of PSIR-FA 20 images was proved statistically. PSIR-FA 20° shows improved tissue contrast as a result of the high accuracy of intensity normalization.
