The measurement and the image of a flue signal flow by means of a function of the nuclear magnetic resonance.

摘要

A method for measuring (direction and magnitude) and imaging fluid flow in an NMR sample. Nuclei in an imaging slice, transaxial, for example, to a direction of fluid flow, are first tagged (saturated or inverted) and then excited to produce a first NMR signal. This signal originates from tagged nuclei in the imaging slice and untagged nuclei which have partially or wholly replaced nuclei flowing out of the slice. Thereafter, nuclei are tagged in a second thicker sample region which includes the imaging slice and extends therefrom in a direction opposite to the fluid flow. The nuclei are again excited in the imaging slice. The NMR signal detected is again from the entire imaging slice but is due entirely to tagged nuclei (if the second slice is selected to have the appropriate thickness) and, therefore, has a smaller magnitude than the first signal. These signals are useful in measuring the fluid flow velocity. The method is also useful, for example, with multiple-angle projection reconstruction and two-dimensional Fourier transform (2DFT) techniques to reconstruct NMR images exhibiting flowing nuclei only.