Band-limited interpolation for maximum intensity projection images

X-ray computed tomography (CT) scanners, due to its inherent scanning geometry, provide images with non-isotropic voxels. The typical CT scanner generates axial slices with the thickness on the order of a few millimeters with sub- millimeter pixels. The multi-slice images obtained with such protocol must be then interpolated across the slices for an effective and realistic 3-D visualization of the patient anatomy. In this paper we focus on the effects of slice interpolation for maximum intensity projection (MIP) images with the projection direction orthogonal to the z-axis, for instance, for the generation of coronal or sagittal views. Linear interpolations, although simple, due to the inherent noise in the data, generate MIP images with noise whose variance vary quadratically along the z-axis. As such, the MIP images will often suffer from horizontal streaking artifacts, exactly at the position of the original slices. To combat this situation we have developed a different interpolation technique based on a digital finite impulse response (FIR) filter. It is shown that this band-limited interpolation based on the FIR filter will flatten the change in the noise variance along the z-axis, the net effect being either the elimination or a reduction of the horizontal streaking artifact.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.