Robust 4D-MRI Sorting with Reduced Artifacts Based on Anatomic Feature Matching
dc.contributor.advisor | Ren, Lei | |
dc.contributor.advisor | Cai, Jing | |
dc.contributor.author | Yang, Zi | |
dc.date.accessioned | 2018-05-31T21:19:05Z | |
dc.date.available | 2020-05-15T08:17:10Z | |
dc.date.issued | 2018 | |
dc.department | Medical Physics | |
dc.description.abstract | Purpose: Motion artifacts induced by breathing variations are common in 4D-MRI images. This study aims to reduce the motion artifacts by developing a novel, robust 4DMRI sorting method based on anatomic feature matching, which is applicable in both cine and sequential acquisition. Method: The proposed method uses the diaphragm as the anatomic feature to guide the sorting of 4D-MRI images. Initially, both abdominal 2D sagittal cine MRI images and axial MRI images (in both axial cine and sequential scanning modes) were acquired. The sagittal cine MRI images were divided into 10 phases as ground truth. Next, the phase of each axial MRI image is determined by matching the diaphragm position in the intersection plane between the axial MRI and the ground truth cine MRI. Then, those matched phases axial MRI images were sorted into 10-phase bins identical to the ground truth cine images. Finally, 10-phase 4D-MRI were reconstructed from these sorted axial MRI images. The accuracy of reconstructed 4D-MRI data was evaluated in a simulation study using the 4D eXtended Cardiac Torso (XCAT) digital phantom with a sphere tumor in the liver. The effects of breathing signal, including both regular (cosine function) and irregular (patient data), on reconstruction accuracy were investigated by calculating total relative error (TRE) of the 4D volumes, Volume-Percent-Difference (VPD) and Center-of-Mass-Shift(COMS) of the simulated tumor between the reconstructed and the ground truth images. Results: In both scanning modes, reconstructed 4D-MRI images matched well with the ground truth except minimal motion artifacts. The averaged TRE of the 4D volume, VPD and COMS of the EOE phase in both scanning modes were 0.32%/1.20%/±0.05𝑚𝑚 for regular breathing, and 1.13%/4.26%/±0.21𝑚𝑚 for patient irregular breathing, respectively. Conclusion: The preliminary results illustrated the robustness of the new 4D-MRI sorting method based on anatomic feature matching. This method improved image quality with reduced motion artifacts in the resulting reconstructed 4D MRI is applicable for axial MR images acquired using both cine and sequential scanning modes. | |
dc.identifier.uri | ||
dc.subject | Medical imaging | |
dc.subject | 4D-MRI | |
dc.subject | Motion artifacts | |
dc.subject | Sorting | |
dc.title | Robust 4D-MRI Sorting with Reduced Artifacts Based on Anatomic Feature Matching | |
dc.type | Master's thesis | |
duke.embargo.months | 24 |