Keywords:
Performed at one institution, Experimental, Not applicable, Image verification, Artifacts, Technical aspects, Radiation therapy / Oncology, Experimental investigations, MR, Oncology, MR physics, MRI
Authors:
Y. kato, K. okudaira, M. kumagai, T. Taoka, T. Kamomae, Y. Itoh, S. Naganawa; Nagoya/JP
DOI:
10.26044/ecr2020/C-01229
Results
The representative combined images from nine positions and geometric distortion vector maps with no-DC, 2D-DC, and 3D-DC are shown in Fig. 5 (direct coronal plane) and Fig. 6 (reconstruction coronal plane from axial images). Figure 7 shows the changes in mean distortion magnitude with distance from the magnetic field center in 2D T1-SE with in-plane (a) and through-plane (b), 2D T2-FSE with in-plane (c) and through-plane (d). Figure 8 shows the changes in mean distortion magnitude with distance from the magnetic field center in 3D T1-GRE with in-plane (a) and through-plane (b), 3D T2-FSE with in-plane (c) and through-plane (d). Table 2 summarizes the distortion magnitude in all sequences within a radius of 20–220 mm from the magnetic field center with in-plane and through-plane for no-DC, 2D-DC, and 3D-DC.The quantified distortion increased with the distance from the magnetic field center. The in-plane distortions were reduced by both 2D- and 3D-DC compared to no-DC in all sequences, whereas the through-plane distortions were reduced by 3D-DC compared to 2D-DC in all sequences. Although there was no difference identified between 2D- and 3D-DC performances in in-plane distortions, there was a remarkable difference noted between 2D- and 3D-DC performances in the through-plane distortions in all sequences. In addition, the distortion magnitude varied among different MR sequences on the edge of FOV using DC.