Stereo Display for Chest CT

摘要

Based on the need to increase the efficacy of chest CT for lung cancer screening, a stereoscopic display for viewing chest CT images has been developed. Stereo image pairs are generated from CT data by conventional stereo projection derived from a geometry that assumes the topmost slice being displayed is at the same distance as the screen of the physical display. Image grayscales are modified to make air transparent so that soft tissue structures of interest can be more easily seen. Because the process of combining multiple slices has a tendency to reduce the effective local contrast, we have included mechanisms to counteract this, such as linear and nonlinear local grayscale transforms. The physical display, which consists of a CRT viewed through shutter glasses, also provides for real-time adjustment of displayed thickness and axial position, as well as for changing brightness and contrast. While refinement of the stereo projection, contrast, and transparency models is ongoing, subjective evaluation of our current implementation indicates that the method has considerable potential for improving the efficiency of the detection of lung nodules. A more quantitative effort to assess its impact on performance, by ROC type methods, is underway.