Abstract: A fully sampled calibration data set, which may be Cartesian k-space data, is used to obtain targeted and optimal interpolation kernels for non-regularly sampled data. The calibration data are self-calibration data obtained from a time-averaged image, or re-sampled data. ACS data are resampled for calibration of region-specific kernels. Subsequently, an explicit noise-based regularized solution can be utilized to estimate region-specific kernels for reconstruction.

Abstract: A system and method for controlling noise in magnetic resonance imaging (MRI) are provided. In one aspect, the method includes reconstructing a series of images of the target using the image data, with each image being defined using signal-to-noise (SNR) units, and selecting an image patch corresponding to the series of images. The method also includes forming a matrix by combining vectors generated using the image patch, and applying a local low rank denoising technique using the matrix and the series of images to generate at least one denoised image.

Abstract: A method for generating a magnetic resonance image includes applying a radio frequency (RF) pulse to a specimen. The method includes modulating a spatially varying magnetic field to impart an angular velocity to a trajectory of a region of resonance relative to the specimen. The method includes acquiring data corresponding to the region of resonance and reconstructing a representation of the specimen based on the data.

Abstract: A system includes a data receiver, a sinogram generator, a processor, a filter module, and an output module. The data receiver is configured to receive radial ordered magnetic resonance data. The sinogram generator is configured to generate a first sinogram corresponding to a view angle as a function of a readout direction for the magnetic resonance data. The processor is configured to generate an oscillogram having an angular frequency axis. The oscillogram corresponds to a Fourier transform of the first sinogram. The filter module is configured to selectively filter a peak in a projection formed along a selected axis of the oscillogram, the peak being related to an interference signal such as an RF interference. The selected axis is orthogonal to the angular frequency axis. The output module is configured to form a second sinogram corresponding to a transform of the filtered projection.

Abstract: A system and method for controlling noise in magnetic resonance imaging (MRI) are provided. In one aspect, the method incudes reconstructing a series of images of the target using the image data, with each image being defined using signal-to-noise (SNR) units, and selecting an image patch corresponding to the series of images. The method also includes forming a matrix by combining vectors generated using the image patch, and applying a local low rank denoising technique using the matrix and the series of images to generate at least one denoised image.

Abstract: Described here are systems and methods for volumetric excitation in magnetic resonance imaging (“MRI”) using frequency modulated radio frequency (“RF”) pulses. In general, quadratic phase modulation along the slice encoding direction is implemented for additional spatiotemporal encoding, which better distributes signal content in the slice direction and enables higher acceleration rates that are robust to slice-undersampling.

Abstract: Methods for fast magnetic resonance imaging (“MRI”) using a combination of outer volume suppression (“OVS”) and accelerated imaging, which may include simultaneous multislice (“SMS”) imaging, data acquisitions amenable to compressed sensing reconstructions, or combinations thereof. The methods described here do not introduce fold-over artifacts that are otherwise common to reduced field-of-view (“FOV”) techniques.

Abstract: A magnetic resonance method and system are provided for providing improved multi-band (MB) magnetic resonance imaging. The adaptive MB imaging can be achieved by providing one or more modified multi-band excitation pulse sequences that include at least either one nullified “dummy” slice within a slab that is not excited simultaneously with the other slices during a single multislice acquisition sequence, or one excitation slice group that utilizes a non-uniform slice spacing between simultaneously excited slices. Adaptive GRAPPA or slice-GRAPPA kernel sizes can also be used during image reconstruction to improve speed without excessive point spread blurring or MB reconstruction failure. A total leakage factor (TLF) can also be determined based on test images using modified MB excitation sequences, and used to improve the adaptive MB procedure.

Abstract: A method includes applying a pulse train to a spin system in a scanner. The pulse train has a plurality of discontinuities in a time domain. The method includes receiving a response from the spin system. The response corresponds to a gated signal. The method includes accessing a correction factor corresponding to the scanner. The method includes calculating a correction to the response based on the correction factor. The method includes generating an output based on the correction.

Abstract: A minimally invasive surgery system including a robot, a cannula assembly and a computer system. The robot has at least one movable robot arm and the cannula assembly is detachably mounted to the robot arm. The cannula assembly includes a cannula and a pattern generating member. The cannula has a distal end and a proximal end with a flange portion and an elongate cannula shaft portion extending from the proximal end to the distal end and an access port through the elongate cannula shaft portion. The pattern generating member includes a pattern light source and a projector temporarily or permanently fixed to the cannula shaft portion. The pattern light source is operatively connected to the projector for projecting a light pattern. The computer system is configured for in real time receiving image data representing light pattern reflections from a surgical surface and for determining a real-time spatial position of the cannula assembly relative to the surgical surface.

Abstract: Positive contrast localization of magnetic (e.g. superparamagnetic) particles in vivo or in vitro by means of SWIFT-MRI using the imaginary component of MR image data in combination with an anatomic reference image derived from the real or magnitude component.

Abstract: A depiction system for generating a real time correlated depiction of movements of a surgical tool for uses in minimally invasive surgery is described. In an embodiment the system includes a computer system, 3D surface data generation means and position data generation means for obtaining real time spatial position data of at least a part of the surgical tool. The 3D surface data generation means or the position data generation is adapted for providing surface position data of at least the target area. The computer system is programmed for determining depiction data representing a depiction of the real time relative spatial position(s) of the surgical tool onto at least a portion of the surface contour of the surface section of the minimally invasive surgery cavity.

Abstract: The invention comprises a cannula assembly kit for a trocar suitable for use in minimally invasive surgery. The cannula assembly kit comprises a cannula and a pattern generating member. The cannula has a distal end and a proximal end and comprises a flange portion at its proximal end and an elongate cannula shaft portion extending from said flange portion to its distal end and an access port through the flange portion and the elongate cannula shaft portion, such that a surgical tool of a surgical instrument can be inserted through the access port. The pattern generating member comprises a pattern light source and a projector arranged such that the pattern light source is operatively connected to the projector for projecting a light pattern. At least the projector of the pattern generating member is configured for being at least temporarily fixed to the cannula shaft portion of the cannula.

Abstract: A method for iteratively calibrating a reconstruction kernel for use in accelerated magnetic resonance imaging (MRI) is provided. An MRI system is used to acquire k-space data from multiple slice locations following the application of a multiband radio frequency (RF) excitation pulse. An initial reconstruction kernel is generated from the acquired k-space data, and this initial reconstruction kernel is used to produce an initial image for each of the multiple slice locations by applying the initial reconstruction kernel to the acquired k-space data. The average phase of each slice location is then calculated from these images, and used to shift the phase values of the subsequently acquired k-space data. From the phase-shifted k-space data, an updated reconstruction kernel is then generated. This process is repeated iteratively until a stopping criterion is satisfied.

Abstract: Positive contrast localization of magnetic (e.g. superparamagnetic) particles in vivo or in vitro by means of SWIFT-MRI using the imaginary component of MR image data in combination with an anatomic reference image derived from the real or magnitude component.

Abstract: The invention relates to a correlated set for minimal invasive surgery comprising a surgical instrument and a pattern generating member, a surgical system, a training kit, a method of training and a meth of performing a minimal invasive surgery. The surgical instrument comprises a handle portion, a surgical tool and a body portion connecting the handle portion to the surgical tool. The pattern generating member comprises a pattern light source and a projector for projecting a light pattern. The projector is adapted for being at least temporarily fixed to the body portion of the surgical instrument such that a movement of said surgical tool results in a correlated movement of said projector.

Abstract: A method for magnetic resonance imaging includes providing a radio frequency excitation pulse to a specimen. The pulse has a duration. The method includes, concurrent with providing the radio frequency excitation pulse, applying a first gradient having a first polarity. The method includes applying a readout gradient at a time after the duration. The readout gradient has inverse polarity relative to the first polarity. The method includes, concurrent with applying the readout gradient, acquiring magnetic resonance data from the specimen. The method includes generating an image based on the magnetic resonance data.

Abstract: A magnetic resonance method and system are provided for providing improved multi-band (MB) magnetic resonance imaging. The adaptive MB imaging can be achieved by providing one or more modified multi-band excitation pulse sequences that include at least either one nullified “dummy” slice within a slab that is not excited simultaneously with the other slices during a single multislice acquisition sequence, or one excitation slice group that utilizes a non-uniform slice spacing between simultaneously excited slices. Adaptive GRAPPA or slice-GRAPPA kernel sizes can also be used during image reconstruction to improve speed without excessive point spread blurring or MB reconstruction failure. A total leakage factor (TLF) can also be determined based on test images using modified MB excitation sequences, and used to improve the adaptive MB procedure.

Abstract: A magnetic resonance image is produced by shifting a gap during acquisition of spin data for a specimen. The spin data is generated by a gapped excitation sequence.

Abstract: A method for iteratively calibrating a reconstruction kernel for use in accelerated magnetic resonance imaging (MRI) is provided. An MRI system is used to acquire k-space data from multiple slice locations following the application of a multiband radio frequency (RF) excitation pulse. An initial reconstruction kernel is generated from the acquired k-space data, and this initial reconstruction kernel is used to produce an initial image for each of the multiple slice locations by applying the initial reconstruction kernel to the acquired k-space data. The average phase of each slice location is then calculated from these images, and used to shift the phase values of the subsequently acquired k-space data. From the phase-shifted k-space data, an updated reconstruction kernel is then generated. This process is repeated iteratively until a stopping criterion is satisfied.