1. A method of rendering a flattened view of a tubular body structure having a lumen defined by a wall, comprising: providing a data set containing data representing a plurality of cross-sectional images of a tubular structure of the body taken along a longitudinal axis of the tubular body; processing the data set to reconstruct a three-dimensional image of the tubular body; identifying a central pathway through a lumen of the three-dimensional image; selecting a starting point along the central pathway; projecting a ray from the starting point to the wall, the direction of the ray corresponding to an angle of view; calculating a voxel value at the location of the wall; storing the voxel value in an image buffer to provide the flattened view; shifting the angle of view by one degree in a selected direction, projecting another ray from the starting point to the wall, the direction of the ray corresponding to the shifted angle of view if the angle of view has not been shifted a total of 180 degrees from the initial starting point, calculating a voxel value at the location of the wall and storing the voxel value in the image buffer; returning to the starting point if the angle of view has been shifted a total of 180 degrees; shifting the angle of view by one degree in a direction opposite from the selected direction, projecting another ray from the starting point to the wall, the direction of the ray corresponding to the shifted angle of view if the angle of view has not been shifted a total of 180 degrees from the initial starting point, calculating a voxel value at the location of the wall and storing the voxel value in the image buffer; advancing the starting point along the longitudinal axis of the lumen by a selected value if the angle of view has been shifted a total of 180 degrees from the initial starting point; displaying the flattened view of the image.