Dynamic 3D MRI data sampling
A magnetic resonance imaging system may include: a magnet; gradient coils; an RF pulse transmitter; an RF receiver that receives MR signals from tissue that has been exposed to RF pulses from the RF pulse generator, gradient fields from the gradient coils, and a magnetic field from the magnet; a system controller that controls the magnet, gradient coils, RF pulse transmitter, and RF receiver so as to generate data representative of at least a portion of the composition of an object, including controlling the gradient coils and RF receiver so as to cause MRI data to be acquired that includes information about at least one attribute of the object at different points in time and that represents an incomplete sample of a portion of k-space that is a Fourier transform of the object; and a data processing system that generates one or more images of at least a portion of the object based on the MRI data.
1. A magnetic resonance imaging system comprising:
a magnet;
gradient coils;
an RF pulse transmitter;
an RF receiver that receives MR signals from tissue that has been exposed to RF pulses from the RF pulse transmitter, gradient fields from the gradient coils, and a magnetic field from the magnet;
a system controller that controls the magnet, gradient coils, RF pulse transmitter, and RF receiver so as to generate data representative of at least a portion of a composition of an object, including controlling the gradient coils and RF receiver so as to cause MRI data to be acquired that includes information about at least one attribute of the object at different points in time and that represents an incomplete sample of a portion of k-space that is a Fourier transform of the object, the MRI data being acquired by full Cartesian sampling along a frequency encoding direction kx with subsampled and/or reordered phase encoded sampling in a ky-kz plane wherein the system controller causes k-space data to be acquired along golden angle radial spokes in the ky-kz plane; and
a data processing system that generates one or more images of at least a portion of the object based on the MRI data.
2. The magnetic resonance imaging system of claim 1 wherein the system controller causes an acquisition of k-space that is processed by a data processing system and, when so processed, produces incoherent artifacts in the one or more images.
3. The magnetic resonance imaging system of claim 2 wherein the incoherent artifacts are produced when a portion of the object is moving or changing.
4. The magnetic resonance imaging system of claim 2 wherein the data processing system chooses a temporal or spatial resolution of the one or more images during or after k-space data is acquired.
5. The magnetic resonance imaging system of claim 1 wherein the system controller causes k-space data to be acquired on a Cartesian grid.
6. The magnetic resonance imaging system of claim 1 wherein the system controller causes k-space data to be acquired at only a portion of locations along each radial spoke.
7. The magnetic resonance imaging system of claim 6 wherein k-space has a center and periphery and the system controller causes k-space data to be acquired at locations near the k-space center more frequently than locations near the k-space periphery.
8. The magnetic resonance imaging system of claim 6 wherein the system controller causes k-space data to be acquired from the k-space periphery to the k-space center.
9. The magnetic resonance imaging system of claim 5 wherein the system controller causes k-space data to be acquired at locations identified by a random or pseudorandom number generator.
10. A non-transitory, tangible, computer-readable storage media containing a program of instructions that, when loaded in an MRI system of the type recited in claim 1 , cause the system controller and data processing system of the MRI system to perform the functions that are recited in claim 1 .
11. The storage media of claim 10 wherein the program of instructions cause the system controller to perform the functions that are recited in claim 2 .
12. The storage media of claim 10 wherein the incoherent artifacts are produced when recited in claim 3 .
13. The storage media of claim 10 wherein the program of instructions cause the data processing system to perform the functions that are recited in claim 4 .
14. The storage media of claim 10 wherein the program of instructions cause the system controller to perform the functions that are recited in claim 5 .
15. The storage media of claim 10 wherein the program of instructions cause the system controller to perform the functions that are recited in claim 6 .
16. The storage media of claim 10 wherein the program of instructions cause the system controller to perform the functions that are recited in claim 7 .
17. The storage media of claim 10 wherein the program of instructions cause the system controller to perform the functions that are recited in claim 8 .
18. The storage media of claim 10 wherein the program of instructions cause the system controller to perform the functions that are recited in claim 9 .