Non-rigid dual respiratory and cardiac motion correction methods after, during, and before image reconstruction for 4D cardiac PET

Abstract

Respiratory motion (RM) and cardiac motion (CM) degrade the quality and resolution in cardiac PET scans. We have developed non-rigid motion estimation methods to estimate both RM and CM based on 4D cardiac gated PET data alone, and compensate the dual respiratory and cardiac (R&C) motions after (MCAR), during (MCDR), and before (MCBR) image reconstruction. In all three R&C motion correction methods, attenuation-activity mismatch effect was modeled by using transformed attenuation maps using the estimated RM. The difference of using activity preserving and non-activity preserving models in R&C correction was also studied. Realistic Monte Carlo simulated 4D cardiac PET data using the 4D XCAT phantom and accurate models of the scanner design parameters and performance characteristics at different noise levels were employed as the known truth and for method development and evaluation. Results from the simulation study suggested that all three dual R&C motion correction methods provide substantial improvement in the quality of 4D cardiac gated PET images as compared with no motion correction. Specifically, the MCDR method yields the best performance for all different noise levels compared with the MCAR and MCBR methods. While MCBR reduces computational time dramatically but the resultant 4D cardiac gated PET images has overall inferior image quality when compared to that from the MCAR and MCDR approaches in the 'almost' noise free case. Also, the MCBR method has better noise handling properties when compared with MCAR and provides better quantitative results in high noise cases. When the goal is to reduce scan time or patient radiation dose, MCDR and MCBR provide a good compromise between image quality and computational times.

Hybrid Imaging: Instrumentation and Data Processing

“…[193], during PET-image reconstruction-motion compensation during image reconstruction (MCIR) [194], and after PETimage reconstruction [195]-Reconstruction Transform Average (RTA). Recent studies have been performed to evaluate the performance of these three methodologies [196,197]. More advanced methods, that use the synergistic information derived from the simultaneous PET and MR data acquisition, have been proposed to estimate [198] and to correct for motion in both PET and MR images [189].…”

Cardiac and Respiratory Motion Correction for Simultaneous Cardiac PET/MR

“…Several methods have been proposed to obtain motion information directly from 18 F-FDG PET scans (7,8,(11)(12)(13). Nevertheless, the accuracy of the estimated motion depends, especially for nonrigid cardiac motion, on sufficient PET uptake in the ventricle.…”

“…For this, the list-mode data are subdivided into different motion states (i.e., binned), and a motion model is used to transform these to a single reference state before the data are combined. Motion correction is achieved either by combining transformed images after image reconstruction (6), as a preprocessing step before image reconstruction (7,8) or during an iterative reconstruction scheme (i.e., motion-corrected image reconstruction [MCIR]) (9). Several techniques derive motion information directly from PET data (7,8,(10)(11)(12).…”

Impact of motion and partial volume effects correction on PET myocardial perfusion imaging using simultaneous PET-MR

“…The inverse motion transformation (i.e. based on the inverse motion fields) was used as an approximation for the transpose motion warping operator ${\mathbf{M}}_{1\to m}^{\mathbf{T}}$ (Li et al ., 2006; Feng et al ., 2015; Furst et al ., 2015). The inverse motion fields were calculated using 3D interpolation of the estimated B-spline registration based motion fields.…”