Magnetic resonance imaging

A non-transitory, computer readable data storage medium encoded with programming instructions, said storage medium being loaded into a computer of a magnetic resonance imaging (MRI) apparatus, and said programming instructions causing said computer to:

• generate a plurality of excitation sequences, wherein generating each excitation sequence includes, in order, generating an imaging magnetic field gradient, and generating a spoiler magnetic field gradient;
• acquire MRI data during the generation of the spoiler magnetic field gradients;
• and
• wherein the spoiler magnetic field gradients are selected such that, during each excitation sequence, the same part of the frequency domain is re-sampled during the generation of the spoiler magnetic field gradient.

A magnetic resonance imaging system comprising a magnet assembly for establishing a magnetic field, at least one gradient coil, and a receiver coil, the MRI system being configured to:

• generate a plurality of excitation sequences by controlling, in order, the at least one gradient coil to generate an imaging magnetic field gradient and, the at least one gradient coil to generate a spoiler magnetic field gradient;
• control the receiver coil to acquire MRI data during the generation of the spoiler magnetic field gradients;
• and
• wherein the spoiler magnetic field gradients are selected such that, during each excitation sequence, the same part of the frequency domain is re-sampled during the generation of the spoiler magnetic field gradient.

A method for identifying spatial motion of an object during the acquisition of magnetic resonance imaging (MRI) data thereof by an MRI apparatus, comprising:

• providing first MRI data representing an object in motion during an MRI scan thereof by said MRI apparatus, the first MRI data comprising a number M of data sets each having a number P of MRI data values, wherein each of the M data sets is associated with an excitation sequence of the MRI scan;
• providing first motion data representing the spatial motion of the object in 3D space during the MRI scan, the first motion data comprising M data sets each having a number R of data values, and wherein each of the R data values represents a degree of freedom in the 3D space;
• determining a linear transformation between the first motion data and the first MRI data such that when the linear transformation is applied to a said MRI data set, the P MRI data values are transformed into said R data values in the 3D space;
• generating second MRI data representing a further object scanned by said MRI apparatus and comprising one or more MRI data sets having P MRI data values in the MRI data space;
• and
• applying the determined linear transform to the one or more MRI data sets of the second MRI data thereby to generate second motion data and therewith identifying spatial motion in said scanned further object.

A non-transitory, computer readable data storage medium encoded with programming instructions, said storage medium being loaded into a computer of a magnetic resonance imaging (MRI) apparatus, and said programming instructions causing said computer to:

• provide first MRI data representing an object in motion during an MRI scan thereof by said MRI apparatus, the first MRI data comprising a number M of data sets each having a number P of MRI data values, wherein each of the M data sets is associated with an excitation sequence of the MRI scan;
• provide first motion data representing the spatial motion of the object in 3D space during the MRI scan, the first motion data comprising M data sets each having a number R of data values, and wherein each of the R data values represents a degree of freedom in the 3D space;
• determine a linear transformation between the first motion data and the first MRI data such that when the linear transformation is applied to a said MRI data set, the P MRI data values are transformed into said R data values in the 3D space;
• generate second MRI data representing a further object scanned by said MRI apparatus and comprising one or more MRI data sets having P MRI data values in the MRI data space;
• and
• apply the determined linear transform to the one or more MRI data sets of the second MRI data thereby to generate second motion data and therewith identifying spatial motion in said scanned further object.

A method of determining object motion during a magnetic resonance imaging (MRI) scan of the object, the method comprising:

• generating a number M of excitation sequences, wherein generating each excitation sequence comprises, in order, generating an imaging magnetic field gradient, and generating a spoiler magnetic field gradient;
• acquiring MRI data during the generation of the spoiler magnetic field gradients, the acquired MRI data comprising M data sets each having a number P of MRI data values;
• processing the MRI data so as to determine whether object motion has occurred by transforming the MRI data into 3D space using a linear transformation;
• and
• wherein the spoiler magnetic field gradients are selected such that, during each excitation sequence, a selected part of the frequency domain is re-sampled during the generation of the spoiler magnetic field gradient.

A magnetic resonance imaging (MRI) system comprising a magnet assembly for establishing a magnetic field, at least one gradient coil, and a receiver coil, the MRI system being configured to:

• generate a plurality of excitation sequences by controlling, in order, the at least one gradient coil to generate an imaging magnetic field gradient and, the at least one gradient coil to generate a spoiler magnetic field gradient;
• control the receiver coil to acquire MRI data during the generation of the spoiler magnetic field gradients;
• wherein the spoiler magnetic field gradients are selected such that, during each excitation sequence, the same part of the frequency domain is re-sampled during the generation of the spoiler magnetic field gradient;
• wherein the MRI system is configured to identify spatial motion of an object during the acquisition of magnetic resonance imaging (MRI) data thereof by the MRI system according to a process, comprising:
• providing first MRI data representing an object in motion during an MRI scan thereof by said MRI apparatus, the first MRI data comprising a number M of data sets each having a number P of MRI data values, wherein each of the M data sets is associated with an excitation sequence of the MRI scan;
• providing first motion data representing the spatial motion of the object in 3D space during the MRI scan, the first motion data comprising M data sets each having a number R of data values, and wherein each of the R data values represents a degree of freedom in the 3D space;
• determining a linear transformation between the first motion data and the first MRI data such that when the linear transformation is applied to a said MRI data set, the P MRI data values are transformed into said R data values in the 3D space;
• generating second MRI data representing an object scanned by said MRI apparatus and comprising one or more MRI data sets having P MRI data values in the MRI data space;
• and
• applying the determined linear transform to the one or more MRI data sets of the second MRI data thereby to generate second motion data and therewith

A non-transitory, computer readable data storage medium encoded with programming instructions, said storage medium being loaded into a computer of a magnetic resonance imaging (MRI) apparatus, and said programming instructions causing said computer to:

• generate a number M of excitation sequences, wherein generating each excitation sequence comprises, in order, generating an imaging magnetic field gradient, and generating a spoiler magnetic field gradient;
• acquire MRI data during the generation of the spoiler magnetic field gradients, the acquired MRI data comprising M data sets each having a number P of MRI data values;
• process the MRI data so as to determine whether object motion has occurred by transforming the MRI data into 3D space using a linear transformation determined by providing first MRI data representing an object in motion during an MRI scan thereof by said MRI apparatus, the first MRI data comprising a number M of data sets each having a number P of MRI data values, wherein each of the M data sets is associated with an excitation sequence of the MRI scan, providing first motion data representing the spatial motion of the object in 3D space during the MRI scan, the first motion data comprising M data sets each having a number R of data values, and wherein each of the R data values represents a degree of freedom in the 3D space, determining a linear transformation between the first motion data and the first MRI data such that when the linear transformation is applied to a said MRI data set, the P MRI data values are transformed into said R data values in the 3D space;
• and
• wherein the spoiler magnetic field gradients are selected such that, during each excitation sequence, a selected part of the frequency domain is re-sampled during the generation of the spoiler magnetic field gradient.