Conjugate symmetry magnetic resonance imaging

Claim 1

A method of magnetic resonance imaging comprising: (a) exciting magnetic resonance of nuclei in an image region; (b) after each excitation of magnetic resonance, causing a magnetic resonance echo during which a magnetic resonance echo signal is generated; (c) applying a phase encode gradient between a maximum positive gradient and a maximum negative phase encode gradient such that the resultant magnetic resonance echo signal is phase encoded in accordance with the phase encode gradient; (d) quatradure detecting and digitizing the magnetic resonance signal to create a view of digial data values; (e) repeating steps (a), (b), (c), and (d) with each of a plurality of phase encode gradients centered around a central phase encode gradient to create centrally encode data values; (f) repeating steps (a), (b), (c), and (d) with each of a plurality of phase encode gradients to create actually collected side data values between the central data values and a view corresponding to one of the maximum positive and negative phase encode gradients; (g) generating a phase map from the centrally encoded data values; (h) generating a set of synthesized data values corresponding to non-collected views between the central data values and a view corresponding to the other of the maximum positive and negative phase encode gradients from the collected side data values; (i) Fourier transforming the central and the collected side data values to form a first image representation; (j) determining complex conjugate values from the phase map and correcting each data value of the first image representation with the complex conjugate of a corresponding value of the phase map to create a phase corrected first image representation; (k) Fourier transforming the synthesized data values to create a second image representation; (l) phase correcting the second image representation in accordance with corresponding values from the phase map; and, (m) combining the first and second phase corrected image representations.

Claim 2

A method of magnetic resonance imaging comprising: (a) exciting magnetic resonance of nuclei in an image region; (b) after each excitation of magnetic resonance, causing a magnetic resonance echo during which a magnetic resonance echo signal is generated; (c) applying a phase encode gradient between a maximum positive gradient and a maximum negative phase encode gradient such that the resultant magnetic resonance echo signal is phase encoded in accordance with the phase encode gradient; (d) quatradure detecting and digitizing the magnetic resonance signal to create a view of digial data values; (e) repeating steps (a), (b), (c), and (d) with each of a plurality of phase encode gradients centered around a central phase encode gradient to create centrally encode data values; (f) repeating steps (a), (b), (c), and (d) with each of a plurality of phase encode gradients to create actually collected side data values between the central data values and a view corresponding to one of the maximum positive and negative phase encode gradients; (g) generating a phase map from the centrally encoded data values; (h) generating a set of synthesized data values corresponding to non-collected views between the central data values and a view corresponding to the other of the maximum positive and negative phase encode gradients from the collected side data values; (i) Fourier transforming the central and the collected side data values to form a first image representation; (j) determining complex conjugate values from the phase map and correcting each data value of the first image representation with the complex conjugate of a corresponding value of the phase map to create a phase corrected first image representation; (k) Fourier transforming the synthesized data values to create a second image representation; (l) phase correcting the second image representation in accordance with corresponding values from the phase map; and, (m) combining the first and second phase corrected image representations.

Claim 3

A method of magnetic resonance imaging comprising: (a) exciting magnetic resonance in an image region; (b) after each excitation of magnetic resonance, causing a magnetic resonance echo during which a magnetic resonance echo signal is generated; (c) applying a phase encode gradient such that the resultant magnetic resonance echo signal is phase encoded in accordance with the phase encode gradient; (d) collecting a central portion of the magnetic resonance echo signal surrounding a central frequency and a side portion of the magnetic resonance signals between the central portion and one extreme of a resonance signal bandwidth; (e) digitizing the collected magnetic resonance echo signal portions to create digital central and side data values; (f) repeating steps (a), (b) (c), (d), and (e) with each of a plurality of phase encode gradients; (g) generating a phase map from the central data values; (h) generating a set of synthesized data values corresponding to frequencies between the central frequency portion and an opposite extreme of the bandwidth from the collected side data values; (i) Fourier transforming the central and side data values to form a first image representation; (j) determining comples conjugate values of the phase map and correcting each data value of the first image representation with the complex conjugate of a corresponding value of the phase map to create a phase corrected first image representation; (k) Fourier transforming the synthesized data values to create a second image representation; (l) phase correcting the second image representation in accordance with corresponding values from the phaes map; and, (m) combining the first and second phase corrected image representations.

Claim 4

A method of magnetic resonance imaging comprising: (a) exciting magnetic resonance in an image region; (b) after each excitation of magnetic resonance, causing a magnetic resonance echo during which a magnetic resonance echo signal is generated; (c) applying a phase encode gradient such that the resultant magnetic resonance echo signal is phase encoded in accordance with the phase encode gradient; (d) collecting a central portion of the magnetic resonance echo signal surrounding a central frequency and a side portion of the magnetic resonance signals between the central portion and one extreme of a resonance signal bandwidth; (e) digitizing the collected magnetic resonance echo signal portions to create digital central and side data values; (f) repeating steps (a), (b) (c), (d), and (e) with each of a plurality of phase encode gradients; (g) generating a phase map from the central data values; (h) generating a set of synthesized data values corresponding to frequencies between the central frequency portion and an opposite extreme of the bandwidth from the collected side data values; (i) Fourier transforming the central and side data values to form a first image representation; (j) determining comples conjugate values of the phase map and correcting each data value of the first image representation with the complex conjugate of a corresponding value of the phase map to create a phase corrected first image representation; (k) Fourier transforming the synthesized data values to create a second image representation; (l) phase correcting the second image representation in accordance with corresponding values from the phaes map; and, (m) combining the first and second phase corrected image representations.

Claim 5

A method of magnetic resonance imaging comprising: generating magnetic resonance data including a first set of centrally encoded data values and a second set of data values which includes half of the remaining data values; generating a phase map from the first data value set; generating a conjugately symmetric third data set from the second data set; Fourier transforming the first and second data value sets; phase correcting the Fourier transformed first and second data sets in accordance with the phase map; Fourier transforming the third data set; phase correcting the Fourier transformed third data set in accordance with the phase map; combining the phase corrected, Fourier transformed data sets to produce an image representation.

Claim 6

A method of magnetic resonance imaging comprising: generating magnetic resonance data including a first set of centrally encoded data values and a second set of data values which includes half of the remaining data values; generating a phase map from the first data value set; generating a conjugately symmetric third data set from the second data set; Fourier transforming the first and second data value sets; phase correcting the Fourier transformed first and second data sets in accordance with the phase map; Fourier transforming the third data set; phase correcting the Fourier transformed third data set in accordance with the phase map; combining the phase corrected, Fourier transformed data sets to produce an image representation.

Claim 17

A method of magnetic resonance imaging comprising: acquiring an incomplete data set in which a peak datum value is off set in one of a phase encode direction and a frequency direction; generating a phase map including: filtering the acquired data set in a neighborhood of the peak datum value, completing a filtered acquired data set with zeroes, inverse Fourier transforming the completed data set to give a complex phase map image with unit magnitude; generating an acquired data image by inverse Fourier transforming the acquired data set; generating a symmetric at image including: creating a symmetric data set which completes the incomplete data set by using a conjugate symmetry relationship therebetween, inverse Fourier transforming the symmetric data set to generate the symmetric data image; correcting the acquired and symmetric images with the phase map image; summing the phase map corrected acquired and symmetric images to create a complex resultant image; and, displaying at least one of a real, imaginary, and magnitude component of the resultant image.

Claim 18

A method of magnetic resonance imaging comprising: acquiring an incomplete data set in which a peak datum value is off set in one of a phase encode direction and a frequency direction; generating a phase map including: filtering the acquired data set in a neighborhood of the peak datum value, completing a filtered acquired data set with zeroes, inverse Fourier transforming the completed data set to give a complex phase map image with unit magnitude; generating an acquired data image by inverse Fourier transforming the acquired data set; generating a symmetric at image including: creating a symmetric data set which completes the incomplete data set by using a conjugate symmetry relationship therebetween, inverse Fourier transforming the symmetric data set to generate the symmetric data image; correcting the acquired and symmetric images with the phase map image; summing the phase map corrected acquired and symmetric images to create a complex resultant image; and, displaying at least one of a real, imaginary, and magnitude component of the resultant image.