Selective material projection imaging system using nuclear magnetic resonance
First Claim
1. In a method for producing selective material projection images of a volume using nuclear magnetic resonance the steps of:
- measuring the two-dimensional projection of a plurality of components of the nuclear magnetic resonance activity using different intensities of the main magnetic field; and
processing these components to produce one or more two-dimensional projection images of specific materials of the volume.
0 Assignments
0 Petitions
Accused Products
Abstract
Two-dimensional projection measurements are formed of the NMR activity within a volume. Measurements are made using different intensities of the main magnetic field, using the different dependencies of relaxation times on magnetic field. The projection measurements are combined to obtain projection images of specific materials within the volume. Projection images are obtained of specific regions within the volume by insuring that the unwanted regions remain insensitized. For improved SNR, projection measurements are repeated to obtain spin-echo signals. The measurements of relaxation times are interleaved so that the data acquisition can occur rapidly.
-
Citations
37 Claims
-
1. In a method for producing selective material projection images of a volume using nuclear magnetic resonance the steps of:
-
measuring the two-dimensional projection of a plurality of components of the nuclear magnetic resonance activity using different intensities of the main magnetic field; and processing these components to produce one or more two-dimensional projection images of specific materials of the volume. - View Dependent Claims (2, 3)
-
-
4. In a method for making a projection image of selected regions of a volume using nuclear magnetic resonance the steps of
initially insensitizing non-selected regions of the volume; -
forming a series of projection measurements of the selected regions of the volume; further insensitizing the non-selected regions of the volume between each projection measurement; and reconstructing the projection image of the selected regions of the volume using the series of projection measurements. - View Dependent Claims (5, 6, 7, 8)
-
-
9. In a method for producing a projection image of a volume using nuclear magnetic resonance the steps of:
-
measuring the projections of the volume; repeating the projection measurements using inverting excitations to produce spin-echo signals; combining the received signals derived from each set of corresponding projection measurements to produce enhanced projection measurements; and processing the enhanced projection measurements to provide the projection image of the volume whereby the signal-to-noise ratio has been enhanced. - View Dependent Claims (10, 11)
-
-
12. In a method for making a projection image of a volume which is sensitive to the nuclear magnetic resonance relaxation time the steps of:
-
exciting a first planar section in the volume using two excitation signals; receiving signals from the first excited planar section following a relaxation interval; similarly exciting other planar sections in the volume parallel to the first planar section such that the first of the excitations occurs before the signals are received from the first planar section; and processing the received signals to provide a projection image sensitive to the relaxation time. - View Dependent Claims (13, 14, 15, 16, 17)
-
-
18. Apparatus for providing selective material projection images of a volume using nuclear magnetic resonance comprising:
-
means for measuring the two-dimensional projection of components of the nuclear magnetic resonance activity using different intensities of the main magnetic field; and means for processing these components to produce one or more two-dimensional projection images of specific materials in the volume. - View Dependent Claims (19, 20)
-
-
21. Apparatus for making projection images of selected regions of a volume using nuclear magnetic resonance comprising:
-
means for initially insensitizing non-selected regions of the volume; means for deriving a sequence of projection measurements of selected regions of the volume; means for further insensitizing the non-selected regions of the volume between each projection measurement; and means for processing the projection measurements to produce the projection image of selected regions of the volume. - View Dependent Claims (22, 23, 24, 25, 26)
-
-
27. Apparatus for producing a projection image of a volume using nuclear magnetic resonance comprising:
-
means for making projection measurements of the volume; means for repeating projection measurements using inversion excitations to produce spin-echo signals; means for combining the signals from corresponding projection measurements to produce enhanced projection measurements; and means for processing the enhanced projection measurements to produce a projection image of the volume. - View Dependent Claims (28, 29)
-
-
30. Apparatus for producing a projection image of a volume which is sensitive to the nuclear magnetic relaxation time comprising:
-
means for exciting a first planar section of the volume using two excitation signals; means for receiving signals from the first excited planar section following a relaxation interval; means for similarly exciting other planar sections in the volume parallel to the first planar section such that the first of the excitations occurs before signals are received from the first section; and means for processing the received signals to provide a projection image sensitive to the relaxation time. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37)
-
Specification