3D gradient spin echo diffusion imaging method for inversion recovery preparation, medium and equipment

Abstract

The invention discloses a 3D gradient spin echo diffusion imaging method for inversion recovery preparation, a medium and equipment. The method comprises the following steps of firstly, in an inversion recovery preparation module, applying 180-degree inversion radio frequency pulse, and setting corresponding inversion recovery time to inhibit cerebrospinal fluid and free water signals; secondly, embedding a pair of trapezoidal cosine oscillation gradients or pulse gradients into 90-degree x-180-degree y-90-degree-x radio frequency pulses through a diffusion coding module, and separating diffusion coding from signal acquisition; then, inhibiting a fat signal by using a fat saturation module; and finally, collecting signals by adopting a 3D gradient spin echo reading mode. The time and the signal-to-noise ratio of magnetic resonance diffusion imaging are improved, accurate measurement of brain tissue diffusion magnetic resonance signal time dependence is facilitated, the effect is especially obvious for a brain area which is near a ventricle and is influenced by the cerebrospinal fluid due to a partial volume effect, and the clinical transformation of a time-dependent diffusion magnetic resonance technology is effectively promoted.

Description

technical field

[0001] The invention relates to the field of magnetic resonance technology, in particular to the field of diffusion magnetic resonance imaging. Background technique

[0002] Diffusion magnetic resonance (dMRI) reveals various details of tissue microstructure by detecting the diffusion of water confined by the microstructural environment. Therefore, the apparent diffusion coefficient (ADC) measured by dMRI usually depends on the diffusion time of water molecules in the surrounding environment (t d ). A series of t d Diffusion of water molecules in the range (milliseconds to tens of milliseconds), and infer tissue microstructure, has been widely used in t d Dependent dMRI studies.

[0003] However, due to the low gradient strength of clinical MRI systems, longer echo times and repetition times are required to achieve reasonable oscillation frequencies and b-values. This leads to issues such as limited ability to access high-frequency oscillatory gradients,...

Examples

Embodiment

[0042] The above-mentioned 3D gradient spin echo diffusion imaging method prepared by inversion recovery, that is, the corresponding 3DIR-OGprep-GRASE sequence, and the 3D gradient spin echo diffusion imaging method without an inversion recovery module, that is, the corresponding 3D OGprep-GRASE sequence in 6 The tests were carried out in three healthy young male volunteers, and the specific parameters here are described below: The magnetic resonance scans used a Siemens Prisma 3T scanner (maximum gradient 80mT / m, maximum switching rate 200mT / m), and all scans were performed using 64 channel head coil.

[0043] Experiment: To compare 3D OGprep-GRASE and 3D IR-OGprep-GRASE sequences on diffusion information in the vicinity of CSF d Accuracy of dependent measurements, scans performed using pulsed diffusion gradient (0 Hz) and oscillating diffusion ladders at 20 Hz, 40 Hz, 60 Hz, other imaging parameters identical: Diffusion weighting = 420 s / mm 2 , 6 directions, 2 repetitions, ...

technical field

[0001] The invention relates to the field of magnetic resonance technology, in particular to the field of diffusion magnetic resonance imaging. Background technique

[0002] Diffusion magnetic resonance (dMRI) reveals various details of tissue microstructure by detecting the diffusion of water confined by the microstructural environment. Therefore, the apparent diffusion coefficient (ADC) measured by dMRI usually depends on the diffusion time of water molecules in the surrounding environment (t d ). A series of t d Diffusion of water molecules in the range (milliseconds to tens of milliseconds), and infer tissue microstructure, has been widely used in t d Dependent dMRI studies.

[0003] However, due to the low gradient strength of clinical MRI systems, longer echo times and repetition times are required to achieve reasonable oscillation frequencies and b-values. This leads to issues such as limited ability to access high-frequency oscillatory gradients,...

Examples

Embodiment

[0042] The above-mentioned 3D gradient spin echo diffusion imaging method prepared by inversion recovery, that is, the corresponding 3DIR-OGprep-GRASE sequence, and the 3D gradient spin echo diffusion imaging method without an inversion recovery module, that is, the corresponding 3D OGprep-GRASE sequence in 6 The tests were carried out in three healthy young male volunteers, and the specific parameters here are described below: The magnetic resonance scans used a Siemens Prisma 3T scanner (maximum gradient 80mT / m, maximum switching rate 200mT / m), and all scans were performed using 64 channel head coil.

[0043] Experiment: To compare 3D OGprep-GRASE and 3D IR-OGprep-GRASE sequences on diffusion information in the vicinity of CSF d Accuracy of dependent measurements, scans performed using pulsed diffusion gradient (0 Hz) and oscillating diffusion ladders at 20 Hz, 40 Hz, 60 Hz, other imaging parameters identical: Diffusion weighting = 420 s / mm 2 , 6 directions, 2 repetitions, ...

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