Signal intensity correction for multichannel MR images using radon transformation
The purpose of this study is to correct signal intensity at low-field MRI system with multichannel receiver coils using Radon transformation and filtered backprojection (FBP) method. An open-type 0.32 T MRI system and a body size phantom were used to acquire the MR images. We used various types of coils from 2-channels to 4-channels, which minimized the loss of signal. In the intensity correction process, Radon transform was used for the images of each channel and low-pass filtering was applied to reduce noise. After that FBP was used for the space transform again from the Radon space to the image space. We also made changes to the projection ranges and their intervals, and then confirmed them to evaluate the optimal parameters. All the intensity corrected results were compared with its original sum-of-square (SOS) images, and the corrected images showed more uniform and homogeneous intensities than the images without correction. In addition, these results were also shown in the quantitative values through the signal intensity variations according to the cut view along the horizontal lines of the images. The feasibility of our approach and results for signal intensity correction may be useful and helpful for the researchers of low-field system with multichannel coils.
intensity correction radon transformation low-field mri filtered backprojection multichannel coil sum-of-square image