Patent ID: 6310479
Filing Date: 2001-10-30
Classification: A61B,G01R

Abstract:
A method for producing an image of a moving object with an MRI system, comprising the steps of:a) altering longitudinal magnetization of spins located outside a selected region of spins that includes the moving object, the step of altering longitudinal magnetization of spins comprising:i) applying a selective RF excitation pulse to produce a flip angle of (90+.alpha.) degrees in the selected region through the moving object; and,ii) applying a non-selective RF excitation pulse to alter spins throughout a volume by a flip angle of negative (90+.alpha.) degrees;b) performing a two-dimensional imaging pulse sequence to acquire NMR signals from spins located in the volume which includes the selected region;c) repeating steps a) and b) until sufficient NMR signals are acquired to form an image data set with which an image can be reconstructed; andd) reconstructing a two-dimensional image in which the NMR signals produced by spins located in the volume are projected onto the two-dimensional image.