1. A non-transitory computer readable storage medium having stored thereon a computer program comprising instructions, which, when executed by a computer, cause the computer to: acquire a set of image data comprising a plurality of image voxels; isolate a set of pulmonary emboli candidates from the plurality of image voxels, the set of pulmonary emboli candidates comprising a subset of the plurality of image voxels; apply a non-linear contrast enhancement to the subset of the plurality of image voxels comprising the set of pulmonary emboli candidates; assign pairs of contrast values to the set of pulmonary emboli candidates, wherein a first contrast value of a respective pair of contrast values corresponds to the non-linear contrast enhancement and a second contrast value of a respective pair of contrast values corresponds to a gray scale range of the initial set of image data; apply a first filter to the set of pulmonary emboli candidates based on the first contrast values to generate a filtered set of pulmonary emboli candidates; apply a second filter to the filtered set of pulmonary emboli candidates to generate a final set of pulmonary emboli candidates, wherein applying the second filter comprises removing pulmonary emboli candidates having second contrast values outside the gray scale range; output the final set of pulmonary emboli candidates; and create an image visually depicting the final set of pulmonary emboli candidates.