TY  - BOOK
AU  - Mahesh Sankar 
TI  - High-speed compressed sensing reconstruction in parallel MRI using modified grappa
KW  - MAGNETIC RESONANCE IMAGING
KW  - RADIOLOGY
KW  - MATLAB
N1  - Project report by an external student from Sree Chitra Thirunal College Of Engineering,Thiruvananthapuram
N2  - High image quality with short acquisition time is desirable for any fast MR imaging application. Parallel MRI is an important technology to achieve these goals. By de-ploying multiple receiver coils, parallel MR imaging can achieve several-fold reductions in scan-time. To reconstruct high quality full-FOV images from under-sampled data, a good reconstruction algorithm is needed.The GeneRalized Autocalibrated Partially Parallel Acquisition (GRAPPA) is a significant Parallel MR Imaging reconstruction technique in frequency domain for subsampled multiple-coil MR data. The additional k-space lines in low frequency region, named as auto calibration signal (ACS) lines, are used to find the relationship between sampled and nonsampled k-space data. Finally, the image is recovered by using sum of squares to combine all coil images. GRAPPA adopts a single finite-size kernel to approximate the true relationship between sampled and non-sampled signals. However, the estimation of this kernel, based on k-space signals is imperfect. Better reconstruction can be achieved by considering low frequency and high frequency regions separately. Here a method of reconstruction dealing with this frequency variation in k-space is implemented
ER  -