33 results about "T2 value" patented technology

The invention relates to the technical field of nuclear magnetic resonance imaging, and discloses a measurement method, device, computer equipment and non-uniform field magnetic resonance system of ADC‑T2 two-dimensional atlas, which can be used in extremely non-uniform magnetic fields or extremely short In the echo time NMR system, the ADC coefficient and T2 value are fitted from multiple sets of echo signals by acquiring multiple echo signals collected by CPMG sequences with different echo intervals, so that the ADC‑ The T2 spectrum eliminates the need for complex diffusion weighted sequences, has the advantages of simple algorithm and low system requirements, and can reduce the cost of hardware systems such as spectrometer equipment, RF power amplifiers, and RF coils. At the same time, the measurement method also has the characteristics of stable algorithm, is not easily affected by flowing liquid, and is also suitable for substances with small T1 / T2.

The invention belongs to the technical field of magnetic resonance imaging, in particular to a method for rapidly quantifying T1ρ based on magnetic resonance fingerprint imaging. The method of the present invention includes adding a spin-lock preparation pulse before the traditional MRF sequence, and through reasonable modeling, the T1ρ evolution of the signal is fused with the T1, T2 evolution of the signal, so that the signal collected at each time point includes T1, T2 and Components of T1ρ. Design the sequence parameters TSL, FA, TR, and TE with pseudo-random changes, and establish a dictionary of different relaxation time value combinations through the evolution of the magnetization vector in the Bloch equation, and match the actually collected image sequence with the dictionary to quantify T1ρ, T1 and T2 values. Compared with the traditional exponential fitting method, the method for quantifying T1ρ of the present invention can greatly shorten the scanning time, and is expected to have greater application value in T1ρ imaging.

The embodiment of the invention discloses a method and a system for determining a transformation relationship between a tight sandstone aperture and a nuclear magnetic resonance T2 value, and relatesto the technical field of oil and gas reservoir stratum geological evaluation. The method comprises the following steps that: carrying out CT (Computed Tomography) on an obtained tight sandstone sample to obtain a three-dimensional digital core; through the three-dimensional digital core, obtaining aperture radius and volume data, and further obtaining a digital core aperture radius distribution diagram; carrying out saturated salt water nuclear magnetic resonance measurement on the tight sandstone sample to obtain a nuclear magnetic resonance T2 spectrogram; and on the basis of the digital core aperture radius distribution diagram and the nuclear magnetic resonance T2 spectrogram, according to an equal porosity principle, establishing a crossplot of the aperture radius rc and the nuclearmagnetic resonance T2 spectrogram, and carrying out fitting to obtain a relational expression of rc and T2. By use of the embodiment of the invention, the quantitative calculation of the transformation relationship between the tight sandstone aperture radius and the nuclear magnetic resonance T2 value is realized. Compared with the transformation relationship obtained through mercury penetration pore throat distribution and the nuclear magnetic resonance T2 spectrogram in the prior art, the transformation relationship obtained by the method is more reliable, and therefore, the tight sandstonereservoir stratum full-scale aperture structure is further accurately represented.