IMAGE CORRECTION USING AN INVERTABLE NETWORK

    公开(公告)号:US20230079353A1

    公开(公告)日:2023-03-16

    申请号:US17474363

    申请日:2021-09-14

    IPC分类号: G06T7/00 G06N20/00 G06T5/00

    摘要: For correction of an image from an imaging system, an inverse solution uses an imaging prior as a regularizer and a physics model of the imaging system. An invertible network is used as the deep-learnt generative model in the regularizer of the inverse solution with the physics model of the degradation behavior of the imaging system. The prior model based on the invertible network provides a closed-form expression of the prior probability, resulting in a more versatile or accurate probability prediction.

    Saliency mapping by feature reduction and perturbation modeling in medical imaging

    公开(公告)号:US11263744B2

    公开(公告)日:2022-03-01

    申请号:US16707209

    申请日:2019-12-09

    摘要: For saliency mapping, a machine-learned classifier is used to classify input data. A perturbation encoder is trained and/or applied for saliency mapping of the machine-learned classifier. The training and/or application (testing) of the perturbation encoder uses less than all feature maps of the machine-learned classifier, such as selecting different feature maps of different hidden layers in a multiscale approach. The subset used is selected based on gradients from back-projection. The training of the perturbation encoder may be unsupervised, such as using an entropy score, or semi-supervised, such as using the entropy score and a difference of a perturbation mask from a ground truth segmentation.

    UNSUPERVISED LEARNING-BASED MAGNETIC RESONANCE RECONSTRUCTION

    公开(公告)号:US20210150783A1

    公开(公告)日:2021-05-20

    申请号:US16688170

    申请日:2019-11-19

    摘要: For magnetic resonance imaging reconstruction, using a cost function independent of the ground truth and many samples of k-space measurements, machine learning is used to train a model with unsupervised learning. Due to use of the cost function with the many samples in training, ground truth is not needed. The training results in weights or values for learnable variables, which weights or values are fixed for later application. The machine-learned model is applied to k-space measurements from different patients to output magnetic resonance reconstructions for the different patients. The weights and/or values used are the same for different patients.

    Automated uncertainty estimation of lesion segmentation

    公开(公告)号:US10970837B2

    公开(公告)日:2021-04-06

    申请号:US16355881

    申请日:2019-03-18

    摘要: Methods and systems are provided for automatically estimating image-level uncertainty for MS lesion segmentation data. A segmentation network is trained to segment MS lesions. The trained segmentation network is then used to estimate voxel level measures of uncertainty by performing Monte-Carlo (MC) dropout. The estimated voxel level uncertainty measures are converted into lesion level uncertainty measures. The information density of the lesion mask, the voxel level measures, and the lesion level measures is increased. A trained network receives input images, the segmented lesion masks, the voxel level uncertainty measures, and the lesion level uncertainty measures and outputs an image level uncertainty measure. The network is trained with a segmentation performance metric to predict an image level uncertainty measure on the segmented lesion mask that is produced by the trained segmentation network.

    Compressed sensing reconstruction for multi-slice and multi-slab acquisitions

    公开(公告)号:US10663549B2

    公开(公告)日:2020-05-26

    申请号:US14552539

    申请日:2014-11-25

    摘要: A method for acquiring a three-dimensional image volume using a magnetic resonance imaging device includes performing a multi-slice or multi-slab acquisition process to acquire a plurality of slices or three-dimensional slabs corresponding to an imaged object. Each respective slice or three-dimensional slab included in the plurality of slices or three-dimensional slabs comprises k-space data. An iterative compressed-sensing reconstruction process is applied to jointly reconstruct the plurality of three-dimensional slabs as a single consistent volume. The iterative compressed-sensing reconstruction process solves a cost function comprising a summation of individual data fidelity terms corresponding to the plurality of three-dimensional slabs.