Compensation for rigid-body patient motion during reconstruction and respiratory motion post-reconstruction in phase-binned slices

Bing Feng, IEEE
Joyoni Dey, IEEE
P. Hendrik Pretorius, IEEE
Richard D. Beach, IEEE
Joseph E. McNamara, University of Massachusetts Medical School
Mark S. Smyczynski, University of Massachusetts Medical School
Karen Johnson, University of Massachusetts Medical School
Michael A. King, IEEE


In SPECT and PET, methods have been developed to track respiratory and patient motion. By acquiring list-mode emission data in synchrony with motion tracking, each type of motion can be corrected. The list-mode events can be binned into respiratory-gated projections by their relative temporal positions within the respiratory cycle. This is called phase-binning. Rigidbody motion can then be corrected during reconstruction using 3D Gaussian interpolation in the projector and backprojector. Finally, registration can be used to combine the phase-binned slices. To evaluate this approach for cardiac SPECT perfusion imaging, a SPECT list-mode acquisition a Tc-99m filled anthropomorphic phantom was performed in synchrony with motion tracking of the phantom using a Polaris IR motion tracking system. The phantom was placed on a board and manually moved with a cyclic axial motion of about 2 cm amplitude, and with additional rigid-body steps of -2 cm followed by 4 cm during SPECT acquisition. An additional SPECT acquisition was performed with the phantom stationary for comparison. Images were obtained for the 4 cases: No motion; Motion-present, no correction of the motion; Motion-present, correction of the patient motion only; And motion-present, correction of both respiratory and patient motion. Results show that correction of both respiratory and patient motion greatly reduced artifact. © 2006 IEEE.