THE VOXEL SENSITIVITY FUNCTION IN FOURIER-TRANSFORM IMAGING - APPLICATIONS TO MAGNETIC-RESONANCE ANGIOGRAPHY

In this paper the problem of small structure visualization in magnetic resonance imaging (MRI) is considered. The relationship between the s tructure and the image intensities is defined in terms of the voxel se nsitivity function (VSF). Using the VSF, the spatial dependence of the voxel signal for small spheres and cylinders is computed. Although th e spatial fluctuation is smaller in the MRI VSF than that which would be obtained from a uniformly sensitive cubical voxel, the deviation st ill results in significant signal loss near the edges and corners of t he voxels. Finally, the VSF formalism is used to demonstrate the impro vement in signal uniformity that can be obtained by using zero-filled (band-limited or sine) interpolation.