creator Hurtado Jaramillo, Juan Sebastian advisor Yang, Yongyi Single photon emission computed tomography (SPECT) is a type of nuclear imaging test that is used for detection of cardiac diseases. Unfortunately it suffers from several image degrading factors, including respiratory motion, that can affect the accuracy of diagnosis. Four-dimensional (4D) respiratory gated SPECT helps to correct this issue by performing the acquisition at several intervals and applying motion-compensated reconstruction methods. With this in mind, and to improve 4D reconstruction, three different motion estimation methods (i.e., optical flow equation, center of mass, and template matching) are applied in this project. Three different sets of dose levels are simulated using NCAT and one set of clinical data is used. The results for motion estimation on simulated data show that the template matching methods have better performance overall. Additionally, noise reduction by means of a spatial smoothing filter helps on the reduction of the average error. Rotational motion estimation using principal component analysis (PCA) was also studied to examine if there can be improvements over the translational motion methods. The initial outcome is that there is a small rotation that can be detected on the ideal reconstruction; the compensation of this rotation also helps to reduce the error obtained from translational motion, albeit by a small margin. Unfortunately, the same cannot be said when noisy reconstructions were used. Submitted by Erma Thomas (thomase@iit.edu) on 2015-07-13T22:28:26Z No. of bitstreams: 2 JuanSebastiánHurtadoJaramillo_MotionEstimationMethodsForRespiratoryGatedSPECT.pdf: 3536314 bytes, checksum: 851d91c6f3efd041e72fd1451e28105c (MD5) JuanSebastiánHurtadoJaramillo_MotionEstimationMethodsForRespiratoryGatedSPECT_TitlePageSigned.pdf: 97005 bytes, checksum: 354d8967b23a76c9f854961f6dfb06ad (MD5) Made available in DSpace on 2015-07-13T22:28:26Z (GMT). No. of bitstreams: 2 JuanSebastiánHurtadoJaramillo_MotionEstimationMethodsForRespiratoryGatedSPECT.pdf: 3536314 bytes, checksum: 851d91c6f3efd041e72fd1451e28105c (MD5) JuanSebastiánHurtadoJaramillo_MotionEstimationMethodsForRespiratoryGatedSPECT_TitlePageSigned.pdf: 97005 bytes, checksum: 354d8967b23a76c9f854961f6dfb06ad (MD5) Previous issue date: 2014-12 M.S. in Electrical Engineering, December 2014 2014 2014-12 http://hdl.handle.net/10560/3455 en Thesis born digital application/pdf In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access ECE / Electrical and Computer Engineering Illinois Institute of Technology Affiliated department