Slab projection (MIP / MinIP / average)

Project a slab of voxels through the MPR planes as MIP, MinIP or average.

A slab projection replaces each reconstructed plane with a summary of the voxels in a slab around it. A maximum intensity projection (MIP) keeps the brightest voxel along each ray, so contrast-filled vessels and lung nodules stand out. A minimum intensity projection (MinIP) keeps the darkest, which shows airways and emphysema. An average reads as a smoothed thick slice.

Steps

1. Open a multi-slice series (⌘O) and switch to 3D MPR.
2. In the Projection control, choose MIP, MinIP or Average. Composite is the ordinary single-plane reconstruction.
3. Set the slab thickness in millimetres. Thin slabs stay close to the original plane; thick slabs cover more anatomy but can hide small detail.

All three planes share one mode and one thickness, because they reconstruct the same volume. See Slab projection for the control itself.

Limits

• The projection returns to Composite when you leave MPR or load a different study.
• A projection is not a slice that exists in the file. Measure and set window/level on Composite.

Result

Axial, sagittal and coronal planes that each show a MIP, MinIP or average of the chosen slab.