About The Research Of The Method Of Reducing Artifacts And Parallel Imaging Algorithm In MRI

In the reconstruction algorithm in MRI, it is very important and practical to improve the quality of images and to speed the imaging. Two missions here are completed. On the one hand, the variable density K space trajectory is utilized to reduce the artifacts images. On the other hand, SENSE parallel images method is studiedIn MRI, undersampling is usually used for reducing the scan time, but it often results in the aliasing artifacts because the sampling frequency is not satisfied by the Nequest frequency. My initial worK is focused on trying to reduce the low frequency components in the images. It is Known that if the K-space, where most energy of an image being concentrated, is uniformly undersampled, the aliasing artifacts will often contain most low frequency components; Furthermore, the edge of K-space contains less energy, which can not lead to severe aliasing if undersampled. So, the variable density sampling method is utilized in both the spiral trajectory imaging and the two-dimensional Fourier transform imaging. It is concluded that this method can significantly reduce the aliasing artifacts by comparing with the uniform undersampling pattern during the same scan time.Based on my initial worK, the reconstruction of SENSE parallel image is studied for further speeding scan time. The method, combining method of partial K space acquisition with the SENSE parallel images, is proposed. It is concluded that this method is efficient and effective by comparing with other reconstruction methods. It is proposed that combining the partial K space acquisition with the parallel acquisition can further speed the scan time.