Systems and methods for non-selective stimulated echo multislice diffusion imaging
View Patent ↗Systems and methods are provided for producing diffusion-weighted images of a subject using a magnetic resonance imaging (MRI) system. The method includes performing a stimulated echo preparation module using non-selective radio-frequency (RF) pulses designed to induce a stimulated echo, performing an acquisition module that includes a multi-slice acquisition of MR data in the presence of diffusion gradients, and reconstructing the diffusion-weighted images of the subject from the MR data.
1 . A method for producing diffusion-weighted images of a subject using a magnetic resonance imaging (MRI) system, the method comprising:
performing a stimulated echo preparation module using non-slice-selective radio-frequency (RF) pulses designed to induce a stimulated echo;
performing an acquisition module that includes a multi-slice acquisition of MR data in the presence of diffusion gradients; and
reconstructing the diffusion-weighted images of the subject from the MR data.
2 . A magnetic resonance imaging (MRI) system comprising:
a magnet system configured to generate a static magnetic field (B 0 ) about at least a portion of a subject arranged in the MRI system;
a plurality of gradient coils configured to apply magnetic gradients to the static magnetic field;
a radio frequency (RF) system configured to apply an excitation field to the subject and acquire MR image data from the subject;
a computer system programmed to:
control the gradient coils and the RF system to:
perform a stimulated echo preparation module using non-selective radio-frequency (RF) pulses designed to induce a stimulated echo;
perform an acquisition module that includes a multi-slice acquisition of MR data in the presence of diffusion gradients; and
reconstruct the diffusion-weighted images of the subject from the MR data.
3 . The method of claim 1 wherein acquisition module includes at least one multiband RF pulse for multiband acquisition of the MR data.
4 . The method of claim 1 wherein the acquisition module is repeated one or more times with one or more revised slice acquisition orders to acquire further MR data that produces at least one of a differential T1 or diffusion decay with the MR data.
5 . The method of claim 1 further comprising performing fat suppression to suppress fat artifacts in the MR data.
6 . The method of claim 1 further comprising applying a gradient during the non-slice-selective RF pulses to reduce an field of view (FOV) for the MR data.
7 . The method of claim 1 wherein the acquisition module is gated to a cardiac cycle of the subject.
8 . The method of claim 1 wherein acquisition module includes a diffusion-sensitized echo-planar pulse sequence.
9 . The system of claim 2 wherein the computer system is further programmed to control the gradient coils and the RF system to repeat the acquisition module one or more times using one or more reordering of slices of the multi-slice acquisition to acquire further MR data.
10 . The system of claim 2 wherein acquisition module includes at least one multiband RF pulse for multiband acquisition of the MR data.
11 . The system of claim 2 wherein the computer system is further programmed to perform fat suppression to suppress fat artifacts in the MR data.
12 . The system of claim 2 wherein the acquisition module is gated to a cardiac cycle of the subject.
13 . The method of claim 4 wherein the revised slice acquisition is a reversed slice order of that used to acquire the MR data.
14 . The method of claim 4 further comprising taking a mathematical combination of the MR data and the further MR data to produce a corrected image with at least one of a corrected T1 or diffusion decay.
15 . The method of claim 5 wherein the fat suppression includes a fat control pulse applied before the non-slice-selective RF pulses to control signal from fat.
16 . The method of claim 5 wherein at least one of the RF pulses and fat suppression includes adiabatic pulses to control signal loss in regions with inconsistent RF transmit fields.
17 . The method of claim 8 wherein the diffusion-sensitized echo-planar pulse sequence is a gradient echo pulse sequence.
18 . The system of claim 9 wherein the reordering includes a reversal of an order of slices used to acquire the MR data.
19 . The system of claim 9 wherein the computer system is further configured to reconstruct the diffusion-weighted images by taking a mathematical combination of the MR data and the further MR data to produce a corrected image with at least one of a corrected T1 or diffusion decay relative to the images produced from the MR data.
20 . The system of claim 11 wherein the fat suppression includes a fat control pulse applied before the non-selective RF pulses to control signal from fat.
21 . The system of claim 11 wherein at least one of the RF pulses and fat suppression includes adiabatic pulses to control signal loss in regions with inconsistent RF transmit fields.
22 . The method of claim 14 wherein the mathematical combination includes a geometric mean.
23 . The method of claim 15 wherein the fat control pulse includes at least one of (a) a frequency selective inversion pulse or non-frequency selective inversion pulse or (b) a fat saturation pulse.
24 . The system of claim 20 wherein the fat control pulse includes at least one of (a) a frequency selective inversion pulse or non-frequency selective inversion pulse or (b) a fat saturation pulse.