Ordered subset expectation maximization
- This article is about an algorithm. For Israeli food corporation, see Osem (company).
Ordered Subset Expectation Maximisation (OSEM) is an algorithm widely used in medical imaging for Positron Emission Tomography, Single Photon Emission Computed Tomography and less frequently for X-Ray Computed Tomography.
It improves upon the speed of previous EM techniques and improves upon the quality of previous FBP (Filtered Back Projection) techniques.