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US 4,411,270 AGranted
Apparatus and method for nuclear magnetic resonance scanning and mapping
OwnerRaymond V. Damadianinventor
Life of this patent
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Abstract
An improved apparatus and method for analyzing the chemical and structural composition of a specimen including whole-body specimens which may include, for example, living mammals, utilizing nuclear magnetic resonance (NMR) techniques. A magnetic field space necessary to obtain an NMR signal characteristic of the chemical structure of the specimen is focused to provide a resonance domain of selectable size, which may then be moved in a pattern with respect to the specimen to scan the specimen.
Claims24
A method of detecting selected nuclei within a specimen comprising:
- (a) providing a primary static magnetic field having a known field configuration in a three dimensional space having an "X", "Y", and "Z" dimensional frame of reference, the primary static magnetic field having a magnetic field orientation in the "Z" direction;
- (b) superimposing a focusing static magnetic field having a magnetic field orientation in the "Z" direction and having a selectable gradient in the "Y" direction on the primary static magnetic field to produce a resulting static magnetic field having a magnetic field orientation in the "Z" direction and having a known field configuration;
- (c) providing a source of oscillating magnetic radiation having a selectable frequency;
- (d) selecting a frequency .omega..sub.o of the source of oscillating magnetic radiation to satisfy the equation:
- .omega..sub.o =.vertline.H.sub.o .vertline..gamma.
- where:
- .omega..sub.o =resonance angular frequency of the selected nuclei
- .vertline.H.sub.o .vertline.=magnitude of resulting static magnetic field at a particular location
- .gamma.=gyromagnetic ratio for the selected nuclei and is a constant for the selected nuclei
- for the selected nuclei at a resonance domain located within the resulting static magnetic field where the field strength is substantially .vertline.H.sub.o .vertline.;
- (e) positioning the specimen such that the resonance domain impinges on the specimen;
- (f) orienting the oscillating magnetic radiation having frequency .omega..sub.o in a direction such that its magnetic field orientation is orthogonal to the "Z" direction;
- (g) directing the oscillating magnetic radiation to the resonance domain whereby a nuclear magnetic resonance signal is generated for the selected nuclei in the specimen located within the resonance domain;
- (h) receiving the nuclear magnetic resonance signal generated;
- and
- (i) processing the nuclear magnetic resonance signal to determine a nuclear magnetic resonance value representing the selected nuclei extant in the resonance domain within the specimen.
13 more elements
Apparatus for detecting selected nuclei within a specimen comprising:
- (a) means for providing a primary static magnetic field having a known field configuration in a three dimensional space having an "X" "Y" and "Z" dimensional frame of reference, the primary static magnetic field having a magnetic field orientation in the "Z" direction;
- (b) means for superimposing a focusing static magnetic field having a magnetic field orientation in the "Z" direction and having a selectable gradient in the "Y" direction on the primary static magnetic field to produce a resulting static magnetic field having a magnetic field orientation in the "Z" direction and having a known field configuration;
- (c) means for providing oscillating magnetic radiation having a selectable frequency;
- (d) means for selecting a frequency .omega..sub.o of the oscillating magnetic radiation to satisfy the equation:
- .omega..sub.o =.vertline.H.sub.o .vertline..gamma.
- .omega..sub.o =resonance angular frequency of the selected nuclei
- H.sub.o =magnitude of resulting static magnetic field at a particular location
- .gamma.=gyromagnetic ratio for the selected nuclei and is a constant for the selected nuclei
- for the selected nuclei at a resonance domain located within the resulting static magnetic field where the field strength is substantially .vertline.H.sub.o .vertline.;
- (e) means for positioning the specimen such that the resonance domain impinges on the specimen;
- (f) means for orienting the oscillating magnetic radiation having the frequency .omega..sub.o in a direction such that its magnetic field orientation is orthogonal to the "Z" direction;
- (g) means for directing the oscillating magnetic radiation to the resonance domain whereby a nuclear magnetic resonance signal is generated for the selected nuclei in the specimen located within the resonance domain;
- (h) means for receiving the nuclear magnetic resonance signal generated;
- and
- (i) means for processing the nuclear magnetic resonance signal to determine a nuclear magnetic resonance value representing the selected nuclei extant in the resonance domain within the specimen.
12 more elements
Dependencies are inferred from the claim text.