US4516075A — NMR scanner with motion zeugmatography

Claim 1

Independent Claim 164 words

In a gyromagnetic resonance instrument which performs a measurement cycle by applying a transverse excitation signal to a gyromagnetic material and to thereby impart a transverse magnetic moment thereto, and which produces a FID signal responsive to emissions by the transversely magnetized gyromagnetic material, the improvement comprising: means for motion sensitizing a FID signal in which a motion sensitizing magnetic field gradient F is applied to the gyromagnetic material for a period of time 2T after its transverse excitation and prior to the production of the FID signal, and wherein the motion sensitizing magnetic field gradient F has alternating polarity with respect to the gyromagnetic material such that its integral over the time period 2T is substantially zero; and detector means for receiving the FID signal and producing therefrom a signal S 1 (t) which is phase-referenced to the cosine phase of the transverse excitation signal and a signal S 2 (t) which is phase-referenced to the sine phase of the transverse excitation signal.

Claim 2

Dependent Claim 164 words

In a gyromagnetic resonance instrument which performs a measurement cycle by applying a transverse excitation signal to a gyromagnetic material and to thereby impart a transverse magnetic moment thereto, and which produces a FID signal responsive to emissions by the transversely magnetized gyromagnetic material, the improvement comprising: means for motion sensitizing a FID signal in which a motion sensitizing magnetic field gradient F is applied to the gyromagnetic material for a period of time 2T after its transverse excitation and prior to the production of the FID signal, and wherein the motion sensitizing magnetic field gradient F has alternating polarity with respect to the gyromagnetic material such that its integral over the time period 2T is substantially zero; and detector means for receiving the FID signal and producing therefrom a signal S 1 (t) which is phase-referenced to the cosine phase of the transverse excitation signal and a signal S 2 (t) which is phase-referenced to the sine phase of the transverse excitation signal.

Claim 3

Dependent Claim 29 words

The instrument as recited in claim 1 in which the motion sensitizing magnetic field gradient F is substantially anti-symmetrical with respect to time T during the time period 2T.

Claim 4

Dependent Claim 52 words

The instrument as recited in claim 1 which includes means for applying a magnetic field gradient G to the gyromagnetic material such that the FID signals which are emitted from a selected location therein are frequency encoded during each measurement cycle and the motion sensitized FID signals are thereby also position sensitized.

Claim 5

Dependent Claim 34 words

The instrument as recited in claim 3 in which the means for generating said field gradients G and F both employ the same set of gradient coils which are positioned around the gyromagnetic material.

Claim 6

Dependent Claim 43 words

The instrument as recited in claim 1 which includes: processor means for performing an inverse Fourier transform on the S 1 (t) and S 2 (t) signals to produce data indicative of motion intensity in the direction of the magnetic field gradient F.

Claim 7

Dependent Claim 108 words

The instrument as recited in claim 1 in which the direction and magnitude of the motion sensitizing magnetic field gradient F is altered for successive measurement cycles to produce a corresponding set of motion sensitized FID signals, and corresponding sets of S 1 (t) and S 2 (t) signals, and which includes: processor means for receiving the sets of S 1 (t) and S 2 (t) signals and performing an inverse Fourier transform thereon to produce a corresponding set of output data indicative of motion intensity in the directions of the magnetic field gradient F; and display means connected to receive the output data and produce an image.

Claim 8

Independent Claim 116 words

A method for producing a FID signal which contains motion information, the steps comprising: applying a polarizing magnetic field to the gyromagnetic material; exciting the gyromagnetic material with a magnetic field B 1 to produce a transverse magnetic moment M 1 therein; applying a motion sensitizing magnetic field gradient F to the gyromagnetic material for a period 2T after its transverse excitation, wherein the polarity of the field gradient F alternates with respect to the gyromagnetic material such that the integral of the field gradient F over the time period 2T is substantially zero; and sensing the FID signal produced by the transversely excited gyromagnetic material over a period of time after the time period 2T.

Claim 9

Independent Claim 116 words

A method for producing a FID signal which contains motion information, the steps comprising: applying a polarizing magnetic field to the gyromagnetic material; exciting the gyromagnetic material with a magnetic field B 1 to produce a transverse magnetic moment M 1 therein; applying a motion sensitizing magnetic field gradient F to the gyromagnetic material for a period 2T after its transverse excitation, wherein the polarity of the field gradient F alternates with respect to the gyromagnetic material such that the integral of the field gradient F over the time period 2T is substantially zero; and sensing the FID signal produced by the transversely excited gyromagnetic material over a period of time after the time period 2T.

Claim 10

Dependent Claim 29 words

The method as recited in claim 7 in which a position sensitizing magnetic field gradient G is applied to the gyromagnetic material while the FID signal is being produced.

Claim 11

Dependent Claim 26 words

The method as recited in claim 7 which includes: processing the FID signal by performing an inverse Fourier transform thereon; and displaying the processed FID signal.

Claim 12

Dependent Claim 153 words

An NMR scanner, the combination comprising: means for generating a polarizing magnetic field B 0 within a gyromagnetic material; means for generating an excitation magnetic field B 1 which produces a transverse magnetic moment in the gyromagnetic material; means for sensing a FID signal produced by the gyromagnetic material excited by said excitation magnetic field B 1 ; means for generating a position magnetic field gradient G in the gyromagnetic material to position sensitize the sensed FID signal and to thereby link the sensed FID signal to a location within the gyromagnetic material; means for generating a motion magnetic field gradient F in the gyromagnetic material to motion sensitize the sensed FID signal and to thereby link the sensed FID signal to the motion of the gyromagnetic material at said location; and processor means for receiving sensed FID signals and producing an image which is modulated by the motion of the gyromagnetic material.

Claim 13

Dependent Claim 153 words

An NMR scanner, the combination comprising: means for generating a polarizing magnetic field B 0 within a gyromagnetic material; means for generating an excitation magnetic field B 1 which produces a transverse magnetic moment in the gyromagnetic material; means for sensing a FID signal produced by the gyromagnetic material excited by said excitation magnetic field B 1 ; means for generating a position magnetic field gradient G in the gyromagnetic material to position sensitize the sensed FID signal and to thereby link the sensed FID signal to a location within the gyromagnetic material; means for generating a motion magnetic field gradient F in the gyromagnetic material to motion sensitize the sensed FID signal and to thereby link the sensed FID signal to the motion of the gyromagnetic material at said location; and processor means for receiving sensed FID signals and producing an image which is modulated by the motion of the gyromagnetic material.

Claim 14

Dependent Claim 54 words

The NMR scanner as recited in claim 10 which includes control means for cyclically generating a series of said FID signals, said control means including: means for altering the position magnetic field gradient G during successive cycles to link the series of FID signals with a succession of different locations in the gyromagnetic material.

Claim 15

Dependent Claim 46 words

The NMR scanner as recited in claim 11 in which the control means alters the motion sensitizing magnetic field gradient F during successive cycles to link a series of FID signals at a specific location in the gyromagnetic material to a succession of different motion values.

Claim 16

Dependent Claim 56 words

The NMR scanner as recited in claim 10 in which the means for generating the motion sensitizing magnetic field gradient F includes control means for producing the field F during each measurement cycle over a period of time 2T with alternating polarity such that the integral of F over the time period 2T is substantially zero.

Claim 17

Dependent Claim 87 words

In an NMR scanner which produces images related to the density distribution of a gyromagnetic phenomena is a gyromagnetic material, the improvement therein comprising: means for motion sensitizing NMR signals produced by the gyromagnetic material, such sensitizing including the application of a magnetic field gradient F of alternating polarity; and means for receiving the motion sensitized NMR signals and producing image data which is related to the density distribution of the gyromagnetic phenomena in the material and which is modulated by the motion of the gyromagnetic material.

Claim 18

Dependent Claim 87 words

In an NMR scanner which produces images related to the density distribution of a gyromagnetic phenomena is a gyromagnetic material, the improvement therein comprising: means for motion sensitizing NMR signals produced by the gyromagnetic material, such sensitizing including the application of a magnetic field gradient F of alternating polarity; and means for receiving the motion sensitized NMR signals and producing image data which is related to the density distribution of the gyromagnetic phenomena in the material and which is modulated by the motion of the gyromagnetic material.

Claim 19

Dependent Claim 44 words

The NMR scanner as recited in claim 14 which includes processor means for receiving said image data and producing an image which is related to the motion of the gyromagnetic material, but which is substantially independent of the density distribution of the gyromagnetic phenomena.

Claim 20

Dependent Claim 77 words

The NMR scanner as recited in claim 14 which includes processor means for receiving said image data and being operable to produce a first data file containing data for the production of an image related to the density distribution of the gyromagnetic phenomena, and being operable to produce a second data file containing data for the production of an image related to the density distribution of the gyromagnetic phenomena modulated by the motion of the gyromagnetic material.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-05-06	1988-11-05	1989-05-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-05-06	1992-11-05	1993-05-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-05-06	1996-11-05	1997-05-07	$7700.00	Window Closed / Lapsed

NMR scanner with motion zeugmatography

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