DANTE fast MR imaging using frequency modulation in NMR

Abstract

Recently ultra fast MR imaging using DANTE sequence have been reported. The advantages of the fast imaging using DANTE pulse sequence are that the method does not require high speed gradient switching on the contrary to the other fast imagings techniques such as the Echo Planar Imaging (EPI) and Spiral Scan Eho Planar Imaging (SEPI) techniques where submillisecond gradient switching are the basic requirement. DANTE fast imaging unlike the other gradient switching based techniques it can be implemented on the conventional MRI system. On the other hand, the original DANTE pulse sequence, excites only a small fraction of imaging voxel is usually selected, that means only a small fraction of the magnetization in each imaging pixel is used, therefore, results in a poor signal to noise ratio (SNR). In this paper, we analyze the SNR of various of DANTE fast imaging sequences and proposed a new FM shaped DANTE sequence with which a substantial amount of the signal to noise ratio can be improved.