Body deformation correction improved the reconstruction of the Single Photon Emission Computed Tomography (SPECT) by considering the body deformation during the imaging procedure. This book is organised by background, body modelling, computation method and results in dissection sequences providing a clear roadmap to understand the research topic. Inside the book, you will find a mathematical motion model of the spine, a modified MLEM algorithm for motion correction purpose and a set of experimental results based on MRI and SPECT modality to illustrate the clinic applicability of this improvement. This work was supported by the National Institute of Biomedical Imaging and Bioengineering by Grant R01-EB001457. The most of the experiments were done in the Nuclear Imaging Lab of University of Massachusetts Medical School with the team of "SPECT Motion Correction" led by Prof. Michael A. King.