Deep learning techniques for suppressing artefacts in magnetic resonance images
Techniques for removing artefacts, such as RF interference and/or noise, from magnetic resonance data. The techniques include: obtaining input magnetic resonance (MR) data using at least one radio-frequency (RF) coil of a magnetic resonance imaging (MRI) system; and generating an MR image from input MR data at least in part by using a neural network model to suppress at least one artefact in the input MR data.
1. A method, comprising:
obtaining input magnetic resonance (MR) data using at least one radio-frequency (RF) coil of a magnetic resonance imaging (MRI) system; and
generating an MR image from the input MR data at least in part by using a neural network model to suppress RF interference in the input MR data, wherein the generating comprises:
performing a reconstruction step by generating an image in an image domain from the input MR data; and
using the neural network model to suppress the RF interference in the input MR data by processing the input MR data before the reconstruction step in a domain other than the image domain,
wherein the neural network model comprises:
a first neural network portion configured to suppress the RF interference in the input MR data in the domain other than the image domain before the reconstruction step, the first neural network portion comprising one or more convolutional layers; and
a second neural network portion configured to suppress noise in the input MR data in the domain other than the image domain before the reconstruction step, the second neural network portion comprising one or more convolutional layers.
2. The method of claim 1 , wherein the generating further comprises using the neural network model to additionally suppress noise in the input MR data by processing the input MR data before the reconstruction step in the domain other than the image domain, wherein the noise is generated by a circuitry in an MR receiver chain of the MRI system and/or by a subject or object being imaged by the MRI system.
3. The method of claim 1 , wherein the RF interference comprises external RF interference generated by a device external to the MRI system.
4. The method of claim 3 , wherein the device external to the MRI system includes a medical device located in a same room as the MRI system.
5. The method of claim 1 , wherein the MRI system includes an imaging region, and wherein the RF interference comprises internal RF interference generated by at least one component of the MRI system located outside of the imaging region.
6. The method of claim 5 , wherein the at least one component of the MRI system includes one or more magnetics components of the MRI system.
7. The method of claim 6 , wherein the one or more magnetics components of the MRI system include a gradient coil of the MRI system.
8. The method of claim 1 ,
wherein the input MR data is in a spatial frequency domain.
9. The method of claim 1 ,
wherein the input MR data is in a sensor domain.
10. The method of claim 1 ,
wherein the neural network model comprises a spectral unpooling layer, and
wherein processing the input MR data with the neural network model comprises applying the spectral unpooling layer.
11. The method of claim 10 , wherein the neural network model further comprises a spectral pooling layer, a plurality of convolutional layers, and a skip connection.
12. The method of claim 10 , wherein applying the spectral unpooling layer comprises applying a pointwise multiplication layer for combining first features having a first resolution provided via a skip connection with second features having a second resolution lower than the first resolution.
13. The method of claim 1 , wherein the neural network model further comprises:
a third neural network portion configured to suppress noise from image-domain data obtained using the input MR data after the reconstruction step.
14. The method of claim 1 , further comprising:
obtaining, during a first time period, RF artefact measurements using the at least one RF coil of the MRI system, wherein the RF artefact measurements include measurements of RF interference and/or noise;
obtaining, during a second time period different from the first time period, MR measurements of a subject in the imaging region of the MRI system;
generating artefact-corrupted MR data by combining the RF artefact measurements with the MR measurements of the subject; and
training the neural network model using the artefact-corrupted MR data.
15. The method of claim 1 , further comprising:
synthesizing RF artefact measurements, wherein the RF artefact measurements include synthesized measurements of RF interference and/or noise;
obtaining MR measurements of a subject in the imaging region of the MRI system;
generating artefact-corrupted MR data by combining the synthesized RF artefact measurements with the MR measurements of the subject; and
training the neural network model using the artefact-corrupted MR data.
16. A system, comprising:
at least one computer hardware processor; and
at least one non-transitory computer-readable storage medium storing processor executable instructions that, when executed by the at least one computer hardware processor, cause the at least one computer hardware processor to perform:
obtaining input magnetic resonance (MR) data using at least one radio-frequency (RF) coil of a magnetic resonance imaging (MRI) system; and
generating an MR image from the input MR data at least in part by using a neural network model to suppress RF interference in the input MR data, wherein the generating comprises:
performing a reconstruction step by generating an image in an image domain from the input MR data; and
using the neural network model to suppress the RF interference in the input MR data by processing the input MR data before the reconstruction step in a domain other than the image domain
wherein the neural network model comprises:
a first neural network portion configured to suppress the RF interference in the input MR data in the domain other than the image domain before the reconstruction step, the first neural network portion comprising one or more convolutional layers; and
a second neural network portion configured to suppress noise in the input MR data in the domain other than the image domain before the reconstruction step, the second neural network portion comprising one or more convolutional layers.
17. A magnetic resonance imaging (MRI) system, comprising:
magnetic components comprising:
a B 0 magnet configured to provide a B 0 field for the MRI system;
gradient coils configured to provide gradient fields for the MRI system; and
at least one RF coil configured to detect magnetic resonance (MR) signals;
a controller configured to:
control at least some of the magnetic components to acquire input MR; and
generating an MR image from the input MR data at least in part by using a neural network model to suppress RF interference in the input MR data, wherein the generating comprises:
performing a reconstruction step by generating an image in an image domain from the input MR data; and
using the neural network model to suppress the RF interference in the input MR data by processing the input MR data before the reconstruction step in a domain other than the image domain,
wherein the neural network model comprises:
a first neural network portion configured to suppress the RF interference in the input MR data in the domain other than the image domain before the reconstruction step, the first neural network portion comprising one or more convolutional layers; and
a second neural network portion configured to suppress noise in the input MR data in the domain other than the image domain before the reconstruction step, the second neural network portion comprising one or more convolutional layers.