| 摘要 |
A method of separating fat and water proton NMR images in the presence of local magnetic field inhomogeneities uses three images acquired with pi , 0, and - pi phase shift between the water and fat signals. A switch function is developed from the argument of the combined images to unambiguously identify the predominant chemical species of each pixel. Wrap arounds in the argument resulting from the limited range of trigonometric functions are treated first by subtracting a low order polynomial, fit to the phase image, to accentuate and remove wrap around discontinuities, and second by using trend analysis to detect and remove discontinuities caused by the wrap arounds. <IMAGE> |
