(A) new phase encoded flow imaging and its application to high speed dynamic NMR tomography

Abstract

In this thesis, the effects of motion in NMR imaging is studied. A new phase encoding method is proposed to obtain the flow images for high speed velocity. The measurement of high speed velocity as well as the methods of moving a artifact correction are discussed according to the motion types which can be classified from spin density variation and the change in flow velocity of spins in the sample. In order to correct moving artifacts, phase compensation using phase coding gradient in pulse sequence is suggested. In addition, as an application to the real human imaging, E.C.G. (electro-cardiogram) gated imaging is performed to obtain blood velocity images of descending aorta and density images of the heart. Computer simulations as well as experiments are carried out and results are presented.