Three dimensional texture analysis of multidetector computed tomography images of the liver

A three dimensional (3-D) Multidetector Computed Tomography (MDCT) liver volume dataset of a patient with colorectal cancer was employed, each slice containing 512 x 512 pixels with pixel dimensions of 0.84 mm x 0.84 mm and slice reconstruction at a 2 mm interval. The 2-D slices were down-sampled to obtain a pixel width of 2mm x 2mm, thus resulting in an isometric cubic voxel of dimension of 2mm(3). A 3-D Laplacian of Gaussian filter mask was generated for different pass-band regions in order to highlight fine to coarse texture within the volume. 3-D Fourier transformations of the liver volume and filter mask were obtained and their product computed. The filtered volume in the spatial domain was obtained by taking the inverse 3-D Fourier transform of this product. This 3D filtered volume highlighted textural features within different bands of spatial frequencies. The 3-D texture of the liver was viewed using maximal intensity projection. We quantify the texture over different spatial scale ranges for 3-D filtered liver volume which may have the potential of improving our preliminary results of 2-D texture analysis of liver images of patients with colorectal cancer and therefore could be employed as a computer assisted diagnostic tool in medical cancer imaging.