LOCAL MAXIMUM INTENSITY PROJECTION (LMIP) - A NEW RENDERING METHOD FOR VASCULAR VISUALIZATION

Purpose: The purpose of our study was to demonstrate a new visualizati on method (local maximum intensity projection; LMIP) that can clearly depict densitometric as well as geometric information in vascular visu alization from 3D data such as obtained from MR and CT angiography. Me thod: LMIP is an extended version of maximum intensity projection (MIP ). However, LMIP differs from MIP in that the latter method selects th e maximum value along an optical ray, whereas LMIP selects the first l ocal maximum value encountered that is larger than a preselected thres hold value along an optical ray from a viewpoint in the viewing direct ion. Results and Conclusion: Examples are presented in which LMIP is u sed to visualize renal vessels from CT angiography data and cerebral v essels in the vicinity of an aneurysm from phase-contrast MR angiograp hy data. We demonstrate that LMIP can clearly depict geometric informa tion, as shaded surface display does, and densitometric information, a s is done by volume rendering, in a straightforward and objective mann er.