Volume rendering for 3-D echocardiography visualization

Volume rendering techniques are particularly useful for the visualization of echographic data which appear noisy, irregular and fuzzy. Data were acquired by means of an annular transducer which rotates around its axis with increments of 3.6 degrees allowing the acquisition of 50 ECG-gated 2-D echography images. The 2-D images acquired in polar coordinates were remapped over a cartesian grid to produce a cube of data. A transfer function that allows the mapping of the 3-D echo data into colour and opacity visual parameters to enhance the regions of interest has been considered. A suitable shading algorithm allows the data to be viewed 3-dimensionally by means of a simple illumination technique. The final 2-D image is obtained by means of a back to front ray casting algorithm