Patents by Inventor Shreyas S. Vasanawala

Shreyas S. Vasanawala has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230380689
    Abstract: Noncontact sensing of subject motion using Doppler radar within a magnetic resonance imaging (MRI) apparatus transmits a band-pass filtered continuous wave radio signal at a microwave frequency and receives a band-pass filtered reflected radio signal. The subject motion is detected from the received band-pass filtered reflected radio signal using a quadrature radio receiver with a software defined radio implementing Doppler radar. A first antenna, used for transmission and reception, is connected to the quadrature radio using band-pass filters and an RF coupler. A second antenna, used for reception, is connected directly to the quadrature radio using band-pass filters. The antennas are positioned in a bore of the MRI apparatus.
    Type: Application
    Filed: May 26, 2023
    Publication date: November 30, 2023
    Inventors: Wonje Lee, Greig C. Scott, John M. Pauly, Shreyas S. Vasanawala
  • Publication number: 20230386101
    Abstract: A method for magnetic resonance imaging (MRI) includes acquiring under-sampled k-space measurements from an MRI apparatus using multiple receiver coils; reconstructing an MRI image from the under-sampled k-space measurements and coil sensitivity maps using an unrolled neural network; generating reconstructed multi-coil k-space data from the MRI image by multiplying the MRI image by the coil sensitivity maps followed by performing a Fourier transform; estimating a k-space null-space convolutional kernel from fully-sampled k-space measurements in autocalibration signal lines of the under-sampled k-space measurements; solving a convex optimization problem to produce refined k-space data from the k-space null-space kernel, the under-sampled k-space measurements, and the reconstructed multi-coil k-space data; and producing a refined MRI image from the refined k-space data by performing an inverse Fourier transform followed by a coil combination using the coil sensitivity maps.
    Type: Application
    Filed: May 26, 2023
    Publication date: November 30, 2023
    Inventors: Shreyas S. Vasanawala, Kanghyun Ryu, Cagan Alkan
  • Patent number: 11823307
    Abstract: A method for MR imaging includes acquiring with an MR imaging apparatus undersampled k-space imaging data having one or more temporal dimensions and two or more spatial dimensions; transforming the undersampled k-space imaging data to image space data using zero-filled or sliding window reconstruction and sensitivity maps; decomposing the image space data into a compressed representation comprising a product of spatial and temporal parts, where the spatial part comprises spatial basis functions and the temporal part comprises temporal basis functions; processing the spatial basis functions and temporal basis functions to produce reconstructed spatial basis functions and reconstructed temporal basis functions, wherein the processing iteratively applies conjugate gradient and convolutional neural network updates using 2D or 3D spatial and 1D temporal networks; and decompressing the reconstructed spatial basis functions and reconstructed temporal basis functions to produce a reconstructed MRI image having one or
    Type: Grant
    Filed: May 13, 2021
    Date of Patent: November 21, 2023
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Christopher Michael Sandino, Shreyas S. Vasanawala, Frank Ong
  • Patent number: 11776679
    Abstract: A method is disclosed for generating pixel risk maps for diagnostic image reconstruction. The method produces uncertainty/variance maps by feeding into a trained encoder a short-scan image acquired from a medical imaging scan to generate latent code statistics including the mean ?y and variance ?y; selecting random samples based on the latent code statistics, z˜N(?y,?y2); feeding the random samples into a trained decoder to generate a pool of reconstructed images; and calculating, for each pixel of the pool of reconstructed images, the pixel mean and variance statistics across the pool of reconstructed images. The risk of each pixel may be calculated using the Stein's Unbiased Risk Estimator on the input density compensated data, that involves calculating the end-to-end divergence of the deep neural network.
    Type: Grant
    Filed: March 9, 2021
    Date of Patent: October 3, 2023
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Morteza Mardani Korani, David Donoho, John M. Pauly, Shreyas S. Vasanawala
  • Publication number: 20230266417
    Abstract: A method for magnetic resonance imaging (MRI) performs a spoiled gradient-recalled (SPGR) MRI scan with an MRI scanner to produce MRI data; and reconstructs an MRI image from the MRI data; wherein performing the SPGR MRI scan comprises playing an interleaved-randomized spoiler (IRS) gradient after every M-th acquisition block, where M?2, and where an absolute area of the IRS gradient of each IRS is randomized between zero and a maximum gradient area achievable on the MRI scanner.
    Type: Application
    Filed: February 24, 2023
    Publication date: August 24, 2023
    Inventors: Zheng Zhong, Christopher Michael Sandino, Shreyas S. Vasanawala
  • Publication number: 20230236272
    Abstract: A method for magnetic resonance imaging performs chemical shift encoded imaging to produce complex dual-echo images which are then applied (with imaging parameters) as input to a deep neural network to produce as output water-only and fat-only images. The deep neural network can be trained with ground truth water/fat images derived from chemical shift encoded images using a conventional water-fat separation algorithm such as projected power approach, IDEAL, or VARPRO. The chemical shift encoded imaging comprises performing an image acquisition with the MRI scanner via a spoiled-gradient echo sequence or a spin-echo sequence.
    Type: Application
    Filed: January 27, 2023
    Publication date: July 27, 2023
    Inventors: Shreyas S. Vasanawala, Yan Wu
  • Patent number: 11681001
    Abstract: A method for magnetic resonance imaging corrects non-stationary off-resonance image artifacts. A magnetic resonance imaging (MRI) apparatus performs an imaging acquisition using non-Cartesian trajectories and processes the imaging acquisitions to produce a final image. The processing includes reconstructing a complex-valued image and using a convolutional neural network (CNN) to correct for non-stationary off-resonance artifacts in the image. The CNN is preferably a residual network with multiple residual layers.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: June 20, 2023
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: David Y. Zeng, Dwight G Nishimura, Shreyas S. Vasanawala, Joseph Y. Cheng
  • Patent number: 11550014
    Abstract: A method for phase-contrast magnetic resonance imaging (PC-MRI) acquires undersampled PC-MRI data using a magnetic resonance imaging scanner and reconstructs MRI images from the undersampled PC-MRI data by reconstructing a first flow-encoded image using a first convolutional neural network, reconstructing a complex difference image using a second convolutional neural network, combining the complex difference image and the first flow-encoded image to obtain a second flow-encoded image, and generating a velocity encoded image from the first flow-encoded image and second flow-encoded image using phase difference processing.
    Type: Grant
    Filed: February 16, 2022
    Date of Patent: January 10, 2023
    Assignees: The Board of Trustees of the Leland Stanford Junior University, The United States of America as represented by The Department Of Veterans Affairs
    Inventors: Daniel B. Ennis, Matthew J. Middione, Julio A. Oscanoa Aida, Shreyas S. Vasanawala
  • Publication number: 20220375141
    Abstract: A method for MR imaging includes acquiring with an MR imaging apparatus undersampled k-space imaging data having one or more temporal dimensions and two or more spatial dimensions; transforming the undersampled k-space imaging data to image space data using zero-filled or sliding window reconstruction and sensitivity maps; decomposing the image space data into a compressed representation comprising a product of spatial and temporal parts, where the spatial part comprises spatial basis functions and the temporal part comprises temporal basis functions; processing the spatial basis functions and temporal basis functions to produce reconstructed spatial basis functions and reconstructed temporal basis functions, wherein the processing iteratively applies conjugate gradient and convolutional neural network updates using 2D or 3D spatial and 1D temporal networks; and decompressing the reconstructed spatial basis functions and reconstructed temporal basis functions to produce a reconstructed MRI image having one or
    Type: Application
    Filed: May 13, 2021
    Publication date: November 24, 2022
    Inventors: Christopher Michael Sandino, Shreyas S. Vasanawala, Frank Ong
  • Publication number: 20220260660
    Abstract: A method for phase-contrast magnetic resonance imaging (PC-MRI) acquires undersampled PC-MRI data using a magnetic resonance imaging scanner and reconstructs MRI images from the undersampled PC-MRI data by reconstructing a first flow-encoded image using a first convolutional neural network, reconstructing a complex difference image using a second convolutional neural network, combining the complex difference image and the first flow-encoded image to obtain a second flow-encoded image, and generating a velocity encoded image from the first flow-encoded image and second flow-encoded image using phase difference processing.
    Type: Application
    Filed: February 16, 2022
    Publication date: August 18, 2022
    Inventors: Daniel B. Ennis, Matthew J. Middione, Julio A. Oscanoa Aida, Shreyas S. Vasanawala
  • Patent number: 11170543
    Abstract: A method of magnetic resonance imaging acquires undersampled MRI data and generates by an adversarially trained generative neural network MRI data having higher quality without using any fully-sampled data as a ground truth. The generative neural network is adversarially trained using a discriminative neural network that distinguishes between undersampled MRI training data and candidate undersampled MRI training data produced by applying an MRI measurement function containing an undersampling mask to generated MRI training data produced by the generative neural network from the undersampled MRI training data.
    Type: Grant
    Filed: January 13, 2020
    Date of Patent: November 9, 2021
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Elizabeth K. Cole, Shreyas S. Vasanawala, Frank Ong, John M. Pauly
  • Patent number: 11125846
    Abstract: A method is disclosed for phase contrast magnetic resonance imaging (MRI) comprising: acquiring phase contrast 3D spatiotemporal MRI image data; inputing the 3D spatiotemporal MRI image data to a three-dimensional spatiotemporal convolutional neural network to produce a phase unwrapping estimate; generating from the phase unwrapping estimate an integer number of wraps per pixel; and combining the integer number of wraps per pixel with the phase contrast 3D spatiotemporal MRI image data to produce final output.
    Type: Grant
    Filed: March 20, 2020
    Date of Patent: September 21, 2021
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Christopher Michael Sandino, Shreyas S. Vasanawala, Joseph Yitan Cheng, Jiacheng Jason He
  • Publication number: 20210287780
    Abstract: A method is disclosed for generating pixel risk maps for diagnostic image reconstruction. The method produces uncertainty/variance maps by feeding into a trained encoder a short-scan image acquired from a medical imaging scan to generate latent code statistics including the mean ?y and variance ?y; selecting random samples based on the latent code statistics, z˜N(?y,?y2); feeding the random samples into a trained decoder to generate a pool of reconstructed images; and calculating, for each pixel of the pool of reconstructed images, the pixel mean and variance statistics across the pool of reconstructed images. The risk of each pixel may be calculated using the Stein's Unbiased Risk Estimator on the input density compensated data, that involves calculating the end-to-end divergence of the deep neural network.
    Type: Application
    Filed: March 9, 2021
    Publication date: September 16, 2021
    Inventors: Morteza Mardani Korani, David Donoho, John M. Pauly, Shreyas S. Vasanawala
  • Patent number: 11085988
    Abstract: A method for magnetic resonance imaging (MRI) includes steps of acquiring by an MRI scanner undersampled magnetic-field-gradient-encoded k-space data; performing a self-calibration of a magnetic-field-gradient-encoding point-spread function using a first neural network to estimate systematic waveform errors from the k-space data, and computing the magnetic-field-gradient-encoding point-spread function from the systematic waveform errors; reconstructing an image using a second neural network from the magnetic-field-gradient-encoding point-spread function and the k-space data.
    Type: Grant
    Filed: March 19, 2020
    Date of Patent: August 10, 2021
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Feiyu Chen, Christopher Michael Sandino, Joseph Yitan Cheng, John M. Pauly, Shreyas S. Vasanawala
  • Publication number: 20210218998
    Abstract: A method of medical imaging includes performing a medical imaging scan to produce acquired imaging data; reconstructing from the acquired imaging data a multi-dimensional medical imaging dataset in the form of a sliceable compressed representation where the reconstruction does not at any stage create full decompressed images; and producing from the sliceable compressed representation a selected image slice by decompressing only a subset of the sliceable compressed representation. The sliceable compressed representation may be stored in a lossless format, and the selected image slice may be displayed on a viewer for visualization.
    Type: Application
    Filed: January 11, 2021
    Publication date: July 15, 2021
    Inventors: Frank Ong, John M. Pauly, Shreyas S. Vasanawala, Michael Lustig, Nien Sin Cedric Yue Sik Kin
  • Publication number: 20210217213
    Abstract: A method of magnetic resonance imaging acquires undersampled MRI data and generates by an adversarially trained generative neural network MRI data having higher quality without using any fully-sampled data as a ground truth. The generative neural network is adversarially trained using a discriminative neural network that distinguishes between undersampled MRI training data and candidate undersampled MRI training data produced by applying an MRI measurement function containing an undersampling mask to generated MRI training data produced by the generative neural network from the undersampled MRI training data.
    Type: Application
    Filed: January 13, 2020
    Publication date: July 15, 2021
    Inventors: Elizabeth K. Cole, Shreyas S. Vasanawala, Frank Ong, John M. Pauly
  • Patent number: 11062490
    Abstract: A magnetic resonance imaging scan performs an MRI acquisition using an undersampling pattern to produce undersampled k-space data; adds the undersampled k-space data to aggregate undersampled k-space data for the scan; reconstructs an image from the aggregate undersampled k-space data; updates the undersampling pattern from the reconstructed image and aggregate undersampled k-space data using a deep reinforcement learning technique defined by an environment, reward, and agent, where the environment comprises an MRI reconstruction technique, where the reward comprises an image quality metric, and where the agent comprises a deep convolutional neural network and fully connected layers; and repeats these steps to produce a final reconstructed MRI image for the scan.
    Type: Grant
    Filed: October 16, 2019
    Date of Patent: July 13, 2021
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: David Y. Zeng, Shreyas S. Vasanawala, Joseph Yitan Cheng
  • Patent number: 10928475
    Abstract: A method for providing magnetic resonance imaging with dynamic contrast and 4D flow of a volume of an object in a magnetic resonance imaging (MRI) system is provided. Contrast agent is provided to the volume of the object. Magnetic resonance excitation from the MRI system is applied to the volume of the object. The MRI system reads out a subsample of less than 10% of spatially resolved data and velocity encoded data with respect to time. The readout subsample is used to determine both dynamic contrast and 4D flow.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: February 23, 2021
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Joseph Y. Cheng, Tao Zhang, John M. Pauly, Shreyas S. Vasanawala
  • Publication number: 20200300955
    Abstract: A method is disclosed for phase contrast magnetic resonance imaging (MRI) comprising: acquiring phase contrast 3D spatiotemporal MRI image data; inputing the 3D spatiotemporal MRI image data to a three-dimensional spatiotemporal convolutional neural network to produce a phase unwrapping estimate; generating from the phase unwrapping estimate an integer number of wraps per pixel; and combining the integer number of wraps per pixel with the phase contrast 3D spatiotemporal MRI image data to produce final output.
    Type: Application
    Filed: March 20, 2020
    Publication date: September 24, 2020
    Inventors: Christopher Michael Sandino, Shreyas S. Vasanawala, Joseph Yitan Cheng, Jiacheng Jason He
  • Publication number: 20200300957
    Abstract: A method for magnetic resonance imaging (MRI) includes steps of acquiring by an MRI scanner undersampled magnetic-field-gradient-encoded k-space data; performing a self-calibration of a magnetic-field-gradient-encoding point-spread function using a first neural network to estimate systematic waveform errors from the k-space data, and computing the magnetic-field-gradient-encoding point-spread function from the systematic waveform errors; reconstructing an image using a second neural network from the magnetic-field-gradient-encoding point-spread function and the k-space data.
    Type: Application
    Filed: March 19, 2020
    Publication date: September 24, 2020
    Inventors: Feiyu Chen, Christopher Michael Sandino, Joseph Yitan Cheng, John M. Pauly, Shreyas S. Vasanawala