What Is MIP (Maximum Intensity Projection)?

What Is MIP (Maximum Intensity Projection)

Maximum intensity projection (MIP) casts a ray through a slab of the volume for every pixel of the output image and keeps the highest value it meets. Bright structures therefore survive and everything dimmer disappears.

That makes it the natural way to look at anything bright and thin spread over many slices: contrast-filled vessels, calcifications, a lung nodule that is hard to spot slice by slice.

The trade-off is depth. Because only the maximum along each ray is kept, a MIP says nothing about which of two bright structures lies in front of the other, and a single very bright voxel — metal, a clip, contrast in an adjacent vessel — can hide what is behind it. This is why a thin slab is usually more informative than projecting the whole volume: it limits how much anatomy is flattened into one image.

A MIP is a projection, not a rendering: it has no lighting and no surfaces, and it is not a substitute for reading the source slices.

In Weasis, see MIP Viewer.