Comparison of partial Fourier reconstruction algorithms in MRI image processing / 重庆医学

Objective To compare the various partial Fourier reconstruction algorithms in MRI image processing and their advantages and disadvantages for improving algorithm .Methods Based on the conjugate symmetry in k‐space data in the partial Fourier reconstruction algorithm theory ,the 1 .5T medical magnetic resonance equipment was utilized ,the k‐space data were collect‐ed ,in reconstruction ,only 55% -80% of full data were utilized to simulate the partial collection pattern and reconstruct the images by using the several algorithms of zero filling ,conjugate synthesis ,Homodyne detection and POCS .Results The results presented that the ringing artifact was most obvious in the conjugate filling pattern and the POCS algorithm had the best effect for eliminating the ringing artifact .Conclusion The POCS algorithm repeatedly uses the weighted iteration with low frequency phase positions , which eliminates artifact ,meanwhile causes the lose of high frequency image details ,moreover the time consuming is longer ;the Ho‐modyne algorithm can keep a good balance between maintaining the image details and diminishing ringing .If the Sinc function serves as a weighting function for conducting phase unwrapping ,the image quality may be further improved .

Overview of optimization of MRI RF coil arrays for parallel imaging / 中国医疗器械杂志

In this paper, an overview is given on the optimization methods of designing RF coil array. Advantages and disadvantages are also discussed.

A new approach to research graphical performance of MRI RF coil based on the quantitative comparison method / 中国医疗器械杂志

<p><b>OBJECTIVE</b>To compare the performance of three different types of RF coil in 3.0T MRI, the signal-to-noise ratio (SNR) and image uniformity in 3.0 Tesla magnetic resonance imaging system have been studied.</p><p><b>MATERIALS AND METHODS</b>In addition to the measurement of SNR and Uniformity based on the protocol recommend by AAPM, the images had also been analyzed using SPSS and MATLAB to get the SNR distribution along two vertical direction and the whole imaging plane.</p><p><b>RESULTS</b>The SNR with T/R birdcage coil and 8-ch surface coil is seven and twelve times higher than surface coil in the region of interest (ROI), which was set in the center of the phantom images. With regard to the spatial variation of sensitivity, the uniformity of T/R birdcage coil and 8-ch surface coil are also much higher than that of surface coil.</p><p><b>CONCLUSION</b>The images from T/R birdcage and phased array coils are all better than those of surface coil. The SNR of the images from phased array coil is highest while the uniformity of the images from T/R birdcage coil is highest.</p>