MaximumIntensityProjection

Maximum Intensity Projection (MIP) is a computer graphics technique used in medical imaging to visualize high-intensity structures within volumetric data. By projecting the voxel with the greatest intensity along each viewing ray to the output image, MIP creates a two-dimensional representation that highlights bright features such as contrast-enhanced vessels in CT or MR datasets.

Implementation typically involves traversing the volume along rays from the viewer’s perspective, keeping the maximum voxel value encountered. The method can be applied in real time and is commonly accelerated by GPU processing. To improve interpretability, data are often pre-processed with contrast enhancement and sometimes thresholding to suppress low-intensity noise; windowing and color mapping may be used to differentiate structures.

Applications include CT angiography and MR angiography to delineate arteries and veins, as well as lung imaging to visualize bronchial and vascular structures. MIP is often used in conjunction with other rendering methods such as MinIP (minimum intensity projection) and isosurface rendering to convey depth and structure.

Limitations include the loss of depth information, as multiple structures along a ray are collapsed into a single pixel; overlapping vessels may obscure relationships and nonvascular high-intensity structures (bone, calcifications) can obscure vasculature unless filtered. Artifacts and noise can mislead interpretation; thus MIP is usually viewed within a broader imaging workflow and interpreted by radiologists.

See also: Minimum Intensity Projection, isosurface rendering, direct volume rendering.