A Multistep Approach for Micro Tomography Obtained Medical Image Segmentation

Images were acquired using micro tomography technique (μCT ). That technique allows to study nondestructive internal structures imaging of any object. X-ray tube generates x-ray electromagnetic radiation which penetrates through the studied sample. Attenuation of x-rays intensity is registered at the opposite side of the sample by two-dimensional detector. Value of x-ray intensity registered in each pixel of the detector depend on materials property across beam path. Captured image is called “projection”. After acquiring one projection sample is rotated by small angle and another projection is captured. Few hundreds or few thousands of projections are acquired. Software reconstruct 3D object from set of projections using one of existing methods. For example filtered back projection method based on Radon transform theorem [8]. The reconstructed object is represented by 3D matrix of voxels. To separate material phases every 2D slice of that matrix should be segmented. That allows to create 3D model of studied sample and calculate volumes of each individual phases. The X-ray measurements presented in this paper were obtained using ”nanotom 180N” device produced by GE Sensing & Inspection Technologies phoenix X-ray Gmbh equipped with nanofocus X-ray tube with maximum 180kV voltage. The tomograms were registered on Hamamatsu 2300x2300 pixel detector and reconstruction of measured objects was done using of proprietary GE software datosX ver. 2.1.0 with Feldkamp algorithm for cone beam X-ray CT [4].