Question

If a multiplanar reformation is rendered as a maximum intensity projection, what CT number will be displayed for a voxel containing mostly air, lung, fluid, and a small amount of iodinated contrast?

Answer 1

Multiplanar reformation (MPR) is a technique used in CT imaging to create new images. The displayed CT number depends on the relative proportions of air, lung, fluid, and contrast.

Step-by-step explanation:

Multiplanar reformation (MPR) is a technique used in medical imaging, specifically in computed tomography (CT), to create new images from existing volumetric data. A maximum intensity projection (MIP) is a type of MPR that displays the maximum intensity of voxels along a given viewing direction.

In the case of a voxel containing mostly air, lung, fluid, and a small amount of iodinated contrast, CT numbers representing the different tissues will be displayed. The CT number for air will be approximately -1000 HU, for lung tissue it will be between -300 and -700 HU, for fluid it will be around 0 HU, and for the iodinated contrast it will be a positive value. Therefore, the displayed CT number for this voxel will depend on the relative proportion of air, lung, fluid, and iodinated contrast within the voxel.