Method for the generation of an NMR spectrum without side-bands

Claim 1

A method for the generation of a nuclear magnetic resonance (NMR) spectrum from a measuring volume comprising the steps of: exposing the measuring volume to a highly homogeneous stationary magnetic field B 0 ; irradiating, in a first run, a first radio frequency (RF)-pulse into the measuring volume to excite nuclear spins; switching on and off a first magnetic gradient field G; recording, in the absence of any magnetic gradient field, a first data set containing first observable measuring signals from the measuring volume; irradiating, in a second run, a second radio frequency (RF)-pulse, which is essentially the same as the first (RF)-pulse, into the measuring volume to excite nuclear spins; switching on and off a second magnetic gradient field -G having a polarity opposite to that of the first magnetic gradient field; recording, in the absence of any magnetic gradient field, a second data set containing second observable measuring signals from the measuring volume; and adding the first data set to the second data set to generate a corrected data set, whereby the corrected data set is subsequently analyzed to produce a spectrum with suppressed eddy current side-bands.

Claim 2

A method for the generation of a nuclear magnetic resonance (NMR) spectrum from a measuring volume comprising the steps of: exposing the measuring volume to a highly homogeneous stationary magnetic field B 0 ; irradiating, in a first run, a first radio frequency (RF)-pulse into the measuring volume to excite nuclear spins; switching on and off a first magnetic gradient field G; recording, in the absence of any magnetic gradient field, a first data set containing first observable measuring signals from the measuring volume; irradiating, in a second run, a second radio frequency (RF)-pulse, which is essentially the same as the first (RF)-pulse, into the measuring volume to excite nuclear spins; switching on and off a second magnetic gradient field -G having a polarity opposite to that of the first magnetic gradient field; recording, in the absence of any magnetic gradient field, a second data set containing second observable measuring signals from the measuring volume; and adding the first data set to the second data set to generate a corrected data set, whereby the corrected data set is subsequently analyzed to produce a spectrum with suppressed eddy current side-bands.

Claim 13

A method for the generation of a nuclear magnetic resonance (NMR) spectrum from a measuring volume comprising the steps of: exposing the measuring volume to a highly homogeneous stationary magnetic field B 0 ; irradiating, in a first run, a first radio frequency (RF)-pulse, with a first pulse frequency ω 1 , into the measuring volume to excite nuclear spins; switching on and off a first magnetic gradient field having at least three first gradient component fields G x , G y , G z with at least one first component field being adapted, in conjunction with the first pulse frequency, to selectively excite nuclear spins in a slice in the measuring volume; compensating for disturbances and distortions of the magnetic field B 0 by changing the size of the static magnetic field B 0 between the first RF-pulse and a subsequent 180° RF-pulse of a spin-echo pulse sequence; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the first gradient field, a first data set containing first observable measuring signals from the measuring volume; irradiating, in a second run, a second radio frequency (RF)-pulse, which is essentially the same as the first RF-pulse and which has a second pulse frequency ω 2 , into the measuring volume to excite nuclear spins; switching on and off a second magnetic gradient field having at least three second gradient component fields -G x , -G y , -G z corresponding to the first gradient component fields with each second component field having a polarity opposite that of the corresponding first component gradient field and with at least one second gradient component field being adapted, in conjunction with the second pulse frequency, to permit selection of the first and the second pulse frequencies to be symmetric with respect to an undisturbed resonance frequency ω 0 of the nuclear spins in the homogeneous magnetic field B 0 and with the first and the second gradient component fields being adapted for selective excitation of nuclear spins in a certain volume element of the measuring volume; suppressing non-interesting resonance signals from at least one of solvents and embedding material; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the second gradient field, a second data set containing second observable measuring signals from the measuring volume; Fourier-transforming the data sets; and adding the Fourier-transformed first data set to the Fourier-transformed second data set to generate a corrected data set, whereby the corrected data set is subsequently analyzed to produce a spectrum with suppressed eddy current side-bands.

Claim 14

A method for the generation of a nuclear magnetic resonance (NMR) spectrum from a measuring volume comprising the steps of: exposing the measuring volume to a highly homogeneous stationary magnetic field B 0 ; irradiating, in a first run, a first radio frequency (RF)-pulse, with a first pulse frequency ω 1 , into the measuring volume to excite nuclear spins; switching on and off a first magnetic gradient field having at least three first gradient component fields G x , G y , G z with at least one first component field being adapted, in conjunction with the first pulse frequency, to selectively excite nuclear spins in a slice in the measuring volume; compensating for disturbances and distortions of the magnetic field B 0 by changing the size of the static magnetic field B 0 between the first RF-pulse and a subsequent 180° RF-pulse of a spin-echo pulse sequence; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the first gradient field, a first data set containing first observable measuring signals from the measuring volume; irradiating, in a second run, a second radio frequency (RF)-pulse, which is essentially the same as the first RF-pulse and which has a second pulse frequency ω 2 , into the measuring volume to excite nuclear spins; switching on and off a second magnetic gradient field having at least three second gradient component fields -G x , -G y , -G z corresponding to the first gradient component fields with each second component field having a polarity opposite that of the corresponding first component gradient field and with at least one second gradient component field being adapted, in conjunction with the second pulse frequency, to permit selection of the first and the second pulse frequencies to be symmetric with respect to an undisturbed resonance frequency ω 0 of the nuclear spins in the homogeneous magnetic field B 0 and with the first and the second gradient component fields being adapted for selective excitation of nuclear spins in a certain volume element of the measuring volume; suppressing non-interesting resonance signals from at least one of solvents and embedding material; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the second gradient field, a second data set containing second observable measuring signals from the measuring volume; Fourier-transforming the data sets; and adding the Fourier-transformed first data set to the Fourier-transformed second data set to generate a corrected data set, whereby the corrected data set is subsequently analyzed to produce a spectrum with suppressed eddy current side-bands.

Claim 15

A method for the generation of a nuclear magnetic resonance (NMR) spectrum from a measuring volume comprising the steps of: exposing the measuring volume to a highly homogeneous stationary magnetic field B 0 ; irradiating, in a first run, a first radio frequency (RF)-pulse, with a first pulse frequency ω 1 , into the measuring volume to excite nuclear spins; switching on and off a first magnetic gradient field having at least three first gradient component fields G x , G y , G z with at least one first component field being adapted, in conjunction with the first pulse frequency, to selectively excite nuclear spins in a slice in the measuring volume; compensating for disturbances and distortions of the magnetic field B 0 by adjusting a first delay between the first RF-pulse and a subsequent 180° RF-pulse of a spin-echo pulse sequence to a value which is different than half of a second delay between further 180° RF-pulses of the spin-echo pulse sequence; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the first gradient field, a first data set containing first observable measuring signals from the measuring volume; irradiating, in a second run, a second radio frequency (RF) pulse, which is essentially the same as the first RF-pulse and which has a second pulse frequency ω 2 , into the measuring volume to excite nuclear spins; switching on and off a second magnetic gradient field having at least three second gradient component fields -G x , -G y , -G z corresponding to the first gradient component fields with each second component field having a polarity opposite that of the corresponding first component gradient field and with at least one second gradient component field being adapted, in conjunction with the second pulse frequency, to permit selection of the first and the second pulse frequencies to be symmetric with respect to an undisturbed resonance frequency ω 0 of the nuclear spins in the homogeneous magnetic field B 0 and with the first and the second gradient component fields being adapted for selective excitation of nuclear spins in a certain volume element of the measuring volume; suppressing non-interesting resonance signals from at least one of solvents and embedding material; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the second gradient field, a second data set containing second observable measuring signals from the measuring volume; Fourier-transforming the data sets; and adding the Fourier-transformed first data set to the Fourier-transformed second data set to generate a corrected data set, whereby the corrected data set is subsequently analyzed to produce a spectrum with suppressed eddy current side-bands.

Claim 16

A method for the generation of a nuclear magnetic resonance (NMR) spectrum from a measuring volume comprising the steps of: exposing the measuring volume to a highly homogeneous stationary magnetic field B 0 ; irradiating, in a first run, a first radio frequency (RF)-pulse, with a first pulse frequency ω 1 , into the measuring volume to excite nuclear spins; switching on and off a first magnetic gradient field having at least three first gradient component fields G x , G y , G z with at least one first component field being adapted, in conjunction with the first pulse frequency, to selectively excite nuclear spins in a slice in the measuring volume; compensating for disturbances and distortions of the magnetic field B 0 by adjusting a first delay between the first RF-pulse and a subsequent 180° RF-pulse of a spin-echo pulse sequence to a value which is different than half of a second delay between further 180° RF-pulses of the spin-echo pulse sequence; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the first gradient field, a first data set containing first observable measuring signals from the measuring volume; irradiating, in a second run, a second radio frequency (RF) pulse, which is essentially the same as the first RF-pulse and which has a second pulse frequency ω 2 , into the measuring volume to excite nuclear spins; switching on and off a second magnetic gradient field having at least three second gradient component fields -G x , -G y , -G z corresponding to the first gradient component fields with each second component field having a polarity opposite that of the corresponding first component gradient field and with at least one second gradient component field being adapted, in conjunction with the second pulse frequency, to permit selection of the first and the second pulse frequencies to be symmetric with respect to an undisturbed resonance frequency ω 0 of the nuclear spins in the homogeneous magnetic field B 0 and with the first and the second gradient component fields being adapted for selective excitation of nuclear spins in a certain volume element of the measuring volume; suppressing non-interesting resonance signals from at least one of solvents and embedding material; recording, in the absence of any magnetic gradient field and within 10 ms after switching off the second gradient field, a second data set containing second observable measuring signals from the measuring volume; Fourier-transforming the data sets; and adding the Fourier-transformed first data set to the Fourier-transformed second data set to generate a corrected data set, whereby the corrected data set is subsequently analyzed to produce a spectrum with suppressed eddy current side-bands.