Ucl Business Plc

King's College London

Sebastien Ourselin

Rachel Sparks

Tom Vercauteren

John Duncan

Richard Cook

Wenqi Li

Daniel Rueckert

Parashkev Nachev

Robin Wolz

Tianrui Zhao

Wenfeng Xia

Michael Hutel

Laurence Lovat

David Hawkes

Baptiste Allain

Mingxing Hu

Alejandro Granados

Manuel Jorge Cardoso

Beate Diehl

Pankaj Daga

Tim Wehner

Guotai Wang

Anna Miserocchi

Andrew McEvoy

Roman Rodionov

Mark Nowell

Gergely Zombori

Jonathan Rohrer

M Jorge Cardoso

Carole Sudre

Lucas Fidon

Stefano Moriconi

Nachev Parashkev

A computer-implemented method of transmitting through a disordered medium from a transmitter to a receiver an image represented as input coherent electromagnetic radiation, the disordered medium having a transmission matrix comprising a plurality of complex-valued transmission constants that relate said input coherent electromagnetic radiation to output electromagnetic radiation at said receiver, which method comprises the steps of:

Apparatus and method for spatial light modulation

A computer implemented method of identifying contacts of an electrode implanted into the brain of a subject via bolts through the skull of the subject, based on an image of the subject, the method comprising: identifying at least one bolt region of the image corresponding to a bolt; identifying one or more contact regions of the image corresponding to electrode contacts; determining contact regions associated with an identified bolt region by searching for identified contact regions, the search being performed based on a search axis extending from the identified bolt region, the direction of the search axis being determined based on the identified bolt region.

Method for identifying electrode contacts implanted into the brain of a subject

A system and method are provided for analysing a functional magnetic resonance imaging (MRI) scan representing a time-sequence, comprising t time points, of images comprising v voxels, where each scan can be represented by a data matrix X. The method comprises modelling the scan data X as the convolution of neural activation time courses Nand a haemodynamic filter Ψ, and performing an inverse operation to estimate N from X and Ψ. The method further compasses decomposing the neural activation time courses N into multiple brain network components by representing N as the product of a first matrix H defining, for each component, a spatial map of the voxels belonging to that component, and a second matrix W defining, for each component, the time sequence of activation of that component during the scan. In other implementations, the matrix decomposition may be performed before the deconvolution.

Apparatus and method for analysing functional MRI data

A computer-implemented method for segmenting an input image, the method comprises: generating a first segmentation of the input image using a first machine learning system, the first segmentation comprising multiple segments; receiving, from a user, at least one indication, wherein each indication corresponds to a particular segment from the multiple segments, and indicates one or more locations of the input image as belonging to that particular segment; constructing, for each segment of the multiple segments having at least one corresponding indication, a respective geodesic distance map, based on the input image and the user indications received for that segment; and generating a second segmentation using a second machine learning system based on the input image and the constructed geodesic distance maps.

System and computer-implemented method for segmenting an image

A computer system and corresponding method are used to assist in planning a trajectory for a surgical insertion into a skull to a target representing an anatomical region. The computer system is configured to: provide the computer system with a three-dimensional image representation of the skull and brain which has been parcellated into anatomical regions, including an identification of critical objects comprising structures within the brain to be avoided during the surgical insertion; provide the computer system with a region of interest comprising an anatomical region within the brain representing the target of the trajectory for the surgical insertion; determine a metric for voxel locations within the anatomical region corresponding to the region of interest, the metric representing the suitability of each of the voxel locations to be a target location for the trajectory; select a set of one or more voxel locations having the greatest suitability according to the metric within the region of interest, each of the one or more selected voxel locations representing a potential target location for the trajectory; and identify a trajectory for the surgical insertion to a potential target location in the region of interest.

System and method for computer-assisted planning of a trajectory for a surgical insertion into a skull

An apparatus is configured for performing a computer-implemented method comprising: receiving data comprising physical measurements of a biological organ across a three-dimensional (3D) volume, the organ having a hierarchical structure of elements with multiple levels; transforming the physical measurement data into a two-dimensional (2D) data representation having first and second axes, wherein the first axis corresponds to location of an element a spatial path through the three-dimensional volume based on the hierarchical structure of the organ, and the second axis corresponds to descending successive levels through said hierarchical structure; and outputting the two-dimensional data representation to an apparatus for display.

Method and apparatus for transforming physical measurement data of a biological organ

A system and method are provided for using a computer system to assist in planning a trajectory (A,B) for a surgical insertion into a skull. The method comprises providing the computer system with a three-dimensional representation of the skull and of critical objects located within the skull, wherein the critical objects comprise anatomical features to be avoided during the surgical insertion. The method further comprises providing the computer system with a target location () for the insertion within the skull. The method further comprises generating by the computer system a first set comprising a plurality of entry points, each entry point () representing a surface location on the skull, and each entry point () being associated (2D) with a trajectory (A,B) from the entry point () to the target location (). The method further comprises discarding by the computer system entry points from the first set to form a second, reduced set comprising a plurality of entry points, wherein an entry point () is discarded from the first set of entry points if the entry point () has an entry angle which fails a condition for being substantially perpendicular to the skull surface. For each entry point () in the second set, the computer system assess the entry point () against a set of one or more criteria, wherein the set of one or more criteria includes a risk factor based on the separation between the critical objects and the trajectory (A,B) which is associated with said entry point ()). This risk factor may be calculated by integrating f(x) along the trajectory (A,B) associated (2D) with the entry point (), where x represents distance along the trajectory (A,B) to a sample point, and f(x) is a function based on distance from the sample point at distance x to a critical object which is nearest to said sample point.

An apparatus and method are provided for performing phase unwrapping for an acquired magnetic resonance (MR) image. The method includes modelling the MR phase in the MR image using a Markov random field (MRF) in which the true phase &#x3c6;(t) and the wrapped phase &#x3c6;(w) are modelled as random variables such that at voxel i of said MR image &#x3c6;(t)(i)=&#x3c6;(w)(i)+2&#x3c0;n(i), where n(i) is an unknown integer that needs to be estimated for each voxel i. The method further includes constructing a graph consisting of a set of vertices V and edges E and two special terminal vertices representing a source s and sink t, where there is a one-to-one correspondence between cuts on the graph and configurations of the MRF, a cut representing a partition of the vertices V into disjoint sets S and T such that s&#x3b5;S and t&#x3b5;T. The method further includes finding the minimum energy configuration, E(n(i)|&#x3c6;(w)) of the MRF on the basis that the total cost of a given cut represents the energy of the corresponding MRF configuration, where the cost of a cut is the sum of all edges going from S to T across the cut boundary. The method further includes using the values of n(i) in the minimum energy configuration to perform the phase unwrapping from &#x3c6;(w) to &#x3c6;(t) for the MR image. A confidence may be computed for each voxel using dynamic graph cuts. The unwrapped phase from two MR images acquired at different times may be used to estimate a field map from the phase difference between the two MR images. The field map may be converted into a deformation field which is then used to initialize a non-rigid image registration of the acquired MR image against a reference image. The deformation field of the non-rigid registration is controlled to be smoother where the confidence is high.

Apparatus and method for correcting susceptibility artefacts in a magnetic resonance image

One embodiment of the invention provides a computer-implemented method of annotating images in a data set comprising a first set of images which initially have annotations and a second set of images which initially do not have annotations. The method comprises the steps of determining spatial correspondences for all pairs of images in the data set, wherein each spatial correspondence represents a mapping of a location in a first image to a corresponding location in a second image. For each mapping, the method further comprises calculating a connection strength between the location in the first image and the corresponding location in the second image. The method further comprises iteratively propagating information across images in the data set using the connection strengths of the mappings as weights for propagating the information, augmented by an estimate of propagation accuracy, wherein the propagated information is used to provide annotations to images which do not initially have annotations, and wherein each iteration performs a propagation across all images in the data set.

System and method for annotating images by propagating information

An apparatus and a computer-implemented method are provided for determining a location in a target image (T) of a site on a surface of a physical object using two or more reference images (I, I) of said physical object that have been obtained with a reference imaging device. Each of said two or more reference images includes said site on the surface of the physical object and was obtained with the reference imaging device having a different position and/or orientation relative to said physical object. The target image is obtained by a target imaging device and includes the site on the surface of the physical object. For each reference image, a set of feature mappings from the reference image to the target image is used to determine the epipolar geometry between the reference image and the target image, and a projection of the site from the reference image onto the target image is calculated from said epipolar geometry. The location in the target image of the site on the surface of the physical object is determined from the calculated epipolar projections for the two or more reference images.

Apparatus and method for determining a location in a target image

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London, United Kingdom

Sebastien Ourselin