Canon Kabushiki Kaisha

Leland Stanford Junior University

Evan G Levine

Brian A Hargreaves

Manuel Martinello

Mahdi Nezamabadi

Bruce L Daniel

Yuxin Hu

Multi-shot diffusion-weighted magnetic resonance imaging acquires multiple k-space segments of diffusion-weighted MRI data, estimates reconstructed multi-shot diffusion weighted images, and combines the estimated images to obtain a final reconstructed MRI image. The estimation of images iteratively calculates updated multi-shot images from the multiple k-space segments and current multi-shot images using a convex model without estimating motion-induced phase, constructs multiple locally low-rank spatial-shot matrices from the updated multi-shot images, and calculates current multi-shot images from spatial-shot matrices.

Motion robust reconstruction of multi-shot diffusion-weighted images without phase estimation via locally low-rank regularization

Shape measurement of a specular object even in the presence of multiple intra-object reflections such as those at concave regions of the object. Silhouettes of the object are extracted, by positioning the object between a camera and a background. A visual hull of the object is reconstructed based on the extracted silhouettes, such as by image capture of shadows of the object projected onto a screen, and image capture of reflections by the surface of the object of coded patterns onto the screen. The visual hull is used to distinguish between direct (single) reflections of the coded patterns at the surface of the object and multiple reflections. Only the direct (single) reflections are used to triangulate camera rays and light rays onto the surface of the object, with multiple reflections being excluded. The 3D surface shape may be derived by voxel carving of the visual hull, in which voxels along the light path of direct reflections are eliminated. For surface reconstruction of heterogeneous objects, which exhibit both diffuse and specular reflectivity, variations in the polarization state of polarized light may be used to separate between a diffuse component of reflection and a specular component.

Shape reconstruction using electronic light diffusing layers (E-Glass)

Accelerated 3D multispectral imaging (MSI) on a magnetic resonance imaging (MRI) system uses phase-encoding in two dimensions and frequency-encoding in the third. The method generates randomized k-space undersampling patterns that vary between different spectral bins to determine k-space samples to be acquired in each spectral bin; orders k-space samples into echo trains that determine gradient waveforms; initializes the gradient waveforms, RF waveforms, and timing information; plays the gradient and RF waveforms using the timing information to excite and refocus different spatial and spectral bin regions; acquires undersampled MRI signal data on the MRI system from the spatial and spectral bin regions; uses robust principal component analysis to reconstruct on-resonance images and off-resonance images represented as sets of low rank and sparse matrices from the undersampled MRI signal data; combines the on-resonance images and off-resonance images to yield a final image; and presents the final image on a display.

Robust principal component analysis for separation of on and off-resonance in 3D multispectral MRI

A system includes cameras; a rotating stage, which has an axis of rotation; one or more computer-readable media; and one or more processors that are coupled to the one or more computer-readable media, the rotating state, and the cameras. Also, the one or more processors are configured to cause the system to control the cameras to capture respective images of a calibration target in a first pose, wherein the calibration target is mounted on the rotating stage; control the rotating stage to rotate through a predetermined angular increment to a second pose; control the cameras to capture respective images of the calibration target in the second pose; and calculate a transformation between two of the cameras based on the respective images of the calibration target in the first pose, on the respective images of the calibration target in the second pose, and on the predetermined angular increment.

Growing community of inventors

Redwood City, CA, United States of America

Evan G Levine