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.