TY - GEN
T1 - Reconstruction of magnetic resonance images from EPI data
AU - McColl, Roderick W.
AU - Clarke, Geoffrey D.
AU - Peshock, Ronald M.M.D.
PY - 1993
Y1 - 1993
N2 - We present a method for reconstructing magnetic resonance (MR) images from data acquired using echo-planar imaging (EPI) techniques. All data were acquired from a commercial scanner, the 1.5 Tesla Picker Vista HPQ MR imaging system, equipped with a special, high-performance, gradient system. Blipped echo planar imaging (BEPI) was performed, with and without digitizer pausing during data acquisition. Both sinusoidal and trapezoidal readout gradients were programmed and tested. Samples obtained from the gradient amplifier current monitors were used to calculate the approximate position of every sample obtained in the spatial-frequency (k-space) plane. A convolution function with compact support int he k-space and good rolloff in the image domain was used to resample the data onto a lattice permitting the use of fast transformation methods to the image domain. Strong ghosting was observed in the resulting images due probably to static magnetic field variation, gradient asymmetry and echo asymmetry between data lines. A piecewise-linear function was used to model the introduced ghost and hence to remove pixels in the reconstructed image which were determined to be spurious. Initial results are promising.
AB - We present a method for reconstructing magnetic resonance (MR) images from data acquired using echo-planar imaging (EPI) techniques. All data were acquired from a commercial scanner, the 1.5 Tesla Picker Vista HPQ MR imaging system, equipped with a special, high-performance, gradient system. Blipped echo planar imaging (BEPI) was performed, with and without digitizer pausing during data acquisition. Both sinusoidal and trapezoidal readout gradients were programmed and tested. Samples obtained from the gradient amplifier current monitors were used to calculate the approximate position of every sample obtained in the spatial-frequency (k-space) plane. A convolution function with compact support int he k-space and good rolloff in the image domain was used to resample the data onto a lattice permitting the use of fast transformation methods to the image domain. Strong ghosting was observed in the resulting images due probably to static magnetic field variation, gradient asymmetry and echo asymmetry between data lines. A piecewise-linear function was used to model the introduced ghost and hence to remove pixels in the reconstructed image which were determined to be spurious. Initial results are promising.
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M3 - Conference contribution
AN - SCOPUS:0027868490
SN - 0819411302
T3 - Proceedings of SPIE - The International Society for Optical Engineering
SP - 158
EP - 168
BT - Proceedings of SPIE - The International Society for Optical Engineering
A2 - Shaw, Rodney
PB - Publ by Society of Photo-Optical Instrumentation Engineers
T2 - Medical Imaging 1993: Physics of Medical Imaging
Y2 - 14 February 1992 through 19 February 1992
ER -