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Image reproduction
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Slice selection
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FBP
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Filtered Back Projection
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Filtered backprojection Filter the measured projection data at different projection angles with a special function. Backproject the filtered projection data to form the reconstructed image. Filtering can be implemented in 2 ways, in the spatial domain, the filter operation is equivalent to to convolving the measured projection data using a special convolving function h(t) More efficient multiplication will be in the spatial frequency domain. FFT the measured projection data into the frequency domain: p(, )=FT {p(t, ) Multiply the the fourier transform projections with the special function. Inverse Fourier transform the product p ’ (, ).
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Phase Encoding Gradient FrequencyPhaseSlice Slice Plane Y or XX or YZXY Z or XX or ZYXZ Z or YY or ZXYZ
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Phase encoding
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K space
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K Space
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Partial K space reconstruction
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Zero padding
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Conjugate symmetry
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Homodyne reconstruction
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