Abstract: A T1-T2* measurement which permits speciation of different components with restricted mobility in samples where a T1-T2 measurement is impossible is disclosed. Tracking the T1-T2* coordinate, and associated signal intensity changes, can reveal additional structural and/or dynamic information such as phase changes in rigid/semi-rigid biopolymer samples or pore level changes in morphology of the water environments in cement-based materials. In another aspect, the T1-T2* measurement may also be employed to discriminate composition in solid mixtures, a very significant analytical problem in industry. In a further aspect, the T1-T2* measurement has particular value in permitting a simple assignment of T1 to different T2* populations.

Abstract: A pure phase encode measurement method where the FID signal is encoded by a brief pure phase encode magnetic field gradient pulse. Data collection occurs once the gradient is turned off. Multiple free induction decay points acquired are identically encoded such that a full k space data set is acquired for each FID point. Fourier transformation of these data sets generates one, two or three dimensional images with consistent fields of view. The image series which results may be fit to a T2* decay function and the T2* magnetic resonance (“MR”) lifetime mapped. Fluid content (proton density) images may also be generated by this simple fitting procedure.

Abstract: Method for correcting the magnetic field gradient waveform in a magnetic resonance measurement including extracting an impulse response from the measured step response of a magnetic resonance system, determining the slew rate of the system during the step response measurement, modifying the desired output waveform such that the desired output waveform is constrained to within the slew rate and the bandwidth of the system, and determining the required pre-equalized input waveform.

Abstract: A method of sampling in pure phase encode MRI including restricting sampled points to a specified region.

Abstract: A slice-selective CPMG pulse sequence with a DANTE-Z selective scheme for measuring spatially-resolved T2 distributions.

Abstract: An MRI sampling method combining phase and frequency encoding.

Abstract: A method of measuring a parameter in a sample by imaging at least a portion of the sample using a spin-echo single-point imaging (SE-SPI) pulse sequence. This method involves applying a pure phase encoding to the SE-SPI pulse sequence, acquiring a multiplicity of echoes, and determining the spatially resolved T2 distribution. In another embodiment, individual echoes are separately phase encoded in a multi-echo acquisition and the SE-SPI pulse sequence is a hybrid SE-SPI sequence. In another embodiment, an external force can be used to build up a distribution of saturations in the sample, and a T2 distribution can be measured for the sample, which is then used to determine a parameter of the sample. A spatially resolved T2 distribution can also be measured and a resulting spatially resolved T2 distribution used to determine the T2 distribution as a function of capillary pressure.

Abstract: Methods for measuring B1 values in an MRI sample space, generating B1 maps and using B1 maps to correct B1 profiles are disclosed.

Abstract: An apparatus and method for performing nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) on samples in metallic holders and vessels or in proximity to metallic objects is disclosed.

Abstract: A method based on pure phase encode FIDs that permits high strength gradient measurement is disclosed. A small doped water phantom (1˜3 mm droplet, T1, T2, T2*<100 ?s) within a microprobe is excited by a series of closely spaced broadband RF pulses each followed by single FID point acquisition. Two trial gradient waveforms illustrate the technique, neither of which could be measured by the conventional microprobe measurement. The first is an extended duration gradient waveform while the other illustrates this method's ability to measure gradient waveforms with large net area and/or high amplitude. This method is a point monitor with simple implementation and low cost hardware requirements.

Abstract: Method for correcting the magnetic field gradient waveform in a magnetic resonance measurement including extracting an impulse response from the measured step response of a magnetic resonance system, determining the slew rate of the system during the step response measurement, modifying the desired output waveform such that the desired output waveform is constrained to within the slew rate and the bandwidth of the system, and determining the required pre-equalized input waveform.

Abstract: A method of measuring a parameter in a sample by imaging at least a portion of the sample using a spin-echo single-point imaging (SE-SPI) pulse sequence. This method involves applying a pure phase encoding to the SE-SPI pulse sequence, acquiring a multiplicity of echoes, and determining the spatially resolved T2 distribution. In another embodiment, individual echoes are separately phase encoded in a multi-echo acquisition and the SE-SPI pulse sequence is a hybrid SE-SPI sequence. In another embodiment, an external force can be used to build up a distribution of saturations in the sample, and a T2 distribution can be measured for the sample, which is then used to determine a parameter of the sample. A spatially resolved T2 distribution can also be measured and a resulting spatially resolved T2 distribution used to determine the T2 distribution as a function of capillary pressure.

Abstract: A method based on pure phase encode FIDs that permits high strength gradient measurement is disclosed. A small doped water phantom (1˜3 mm droplet, T1, T2, T2*<100 ?s) within a microprobe is excited by a series of closely spaced broad-band RF pulses each followed by single FID point acquisition. Two trial gradient waveforms illustrate the technique, neither of which could be measured by the conventional microprobe measurement. The first is an extended duration gradient waveform while the other illustrates this method's ability to measure gradient waveforms with large net area and/or high amplitude. This method is a point monitor with simple implementation and low cost hardware requirements.

Abstract: An apparatus and method for performing nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) on samples in metallic holders and vessels or in proximity to metallic objects is disclosed.

Abstract: A method and apparatus are provided for measuring a parameter such as capillary pressure in porous media such as rock samples. The method comprises mounting a sample in a centrifuge such that different portions of the sample are spaced at different distances from the centrifuge axis, rotating the sample about the axis, measuring a first parameter in the different portions of the sample, and determining the value of a second parameter related to the force to which each portion is subjected due to rotation of the sample. In one embodiment, the first parameter is relative saturation of the sample as measured by MRI techniques, and the second parameter is capillary pressure.

Abstract: A method and apparatus are provided for measuring a parameter such as capillary pressure in porous media such as rock samples. The method comprises mounting a sample in a centrifuge such that different portions of the sample are spaced at different distances from the centrifuge axis, rotating the sample about the axis, measuring a first parameter in the different portions of the sample, and determining the value of a second parameter related to the force to which each portion is subjected due to rotation of the sample. In one embodiment, the first parameter is relative saturation of the sample as measured by MRI techniques, and the second parameter is capillary pressure.

Abstract: A unilateral NMR sensor comprising a ferromagnetic yoke; a permanent magnet arranged on the yoke; a pole piece on the magnet; the pole piece including an air-pole piece interface surface whose shape corresponds to an equipotential contour of magnetic scalar potential