US 12,700,159 B2Granted

Method for use in x-ray CT image reconstruction

AssigneeKoninklijke Philips N.V.

InventorsChristian Haase, Michael Grass, Thomas Heiko Stehle, Sr., Frank Bergner, Sebastian Wild

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Abstract

A method for use in image reconstruction of CT projection data, which aims at reducing motion artefacts in reconstructed images caused by movement of anatomical bodies. Embodiments are based on mitigating motion artefacts based on restricting the range of data that is used for reconstructing each slice. More particularly, a sub-range of the projection data corresponding to each slice is selected, this sub-range being chosen based on determining one or more sub-windows of visibility of a target anatomical object or event within the projection data sequence. The event may be a particular phase of a movement cycle of the anatomical body. The structure could be a particular portion of the anatomical body which is of interest. Either approach leads to reduction of motion artefacts within a single slice, by restricting the data range, and focusing upon the data which is most relevant clinically.

A medical computed tomography (CT) device, comprising:

a memory that stores a plurality of instructions;
and
a processor that couples to the memory and is configured to execute the plurality of instructions to:
obtain an input CT projection data set comprising a plurality of data subsets, each subset corresponding to a different respective slice through a scanned body, and wherein each data subset comprises data corresponding to a defined range of acquisition angles, and a defined acquisition time range;
identify at least one temporal or angular sub-window within the input projection data set associated with visibility in said data set, if reconstructed, of a desired anatomical feature or event;
select from the data subset for each slice a temporal or angular sub-range of the data, smaller than a complete range for each slice, wherein selection of the sub-range is based on at least one of the identified at least one temporal or angular sub-window in the projection data;
generate a data output indicative of the selected sub-range for each slice;
perform a first image reconstruction of each of the slices using a complete data range of the data subset for each slice to derive a first image for each slice;
apply low-pass filtering to each of the first images;
perform a second image reconstruction for each of the slices using the identified sub-range of the data subset for each slice to derive a second image for each slice;
apply high pass filtering to each of the second images;
generate a combined image for each slice comprising a combination of the filtered first and second images, wherein generating the combined image for each slice comprises adding a low-frequency part of the first image reconstructed from the complete data range of the data subset to a high-frequency part of the second image reconstructed from the sub-range of the data subset;
and
generate an output indicative of the combined image for each slice.

11 more elements

Facts

Application

18/036,204Filed 4 Nov 2021

Priority

EP 2020720212 Nov 2020

Published

US 2023/0419563 A128 Dec 2023

Granted

4 Aug 2026

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

G06T 12/10
Tomographic reconstruction from projections: image preprocessing, e.g. calibration, positioning of sources or scatter correction
G06T 12/20
Tomographic reconstruction from projections: inverse problem, i.e. transformations from projection space into object space
G06T 7/337
Using feature-based methods: involving reference images or patches
G06T 7/38
Determination of transform parameters for the alignment of images, i.e. image registration: registration of image sequences

Abstract

Claims13