Image processing unit and method of associating stored images with current images
AssigneeKoninklijke Philips Electronics N.V.
InventorsKai Eck, Geert Gijsbers, Sabine Mollus
Life of this patent
Estimating the term…
Abstract
The invention relates to the association of a current (X-ray image) image of a body volume with one of several stored previous images, the ECG and the respiratory cycle being determined each time together with the images. Using this data, that one of the previous images is chosen which is closest to the current image in respect of cardiac rhythm and respiratory cycle. The resultant association yields a very high accuracy enabling superposed reproduction of the current image and the associated previous image.
Claims20
An image processing unit which comprises:
- an input for the signal of a current image of a body volume, the body volume being subject to a motion comprising several phases of motion;
- at least one input for a signal which represents the phase of motion of the body volume which belongs to the current image;
- a memory in which previous images of the body volume are stored together with the associated phases of motion;
- and
- a controller for:
- calculation of a similarity measure between the current image and a representative image, the similarity measure being associated with the phase of motion;
- calculation of the similarity measure between the representative image and the previous images or a sub-quantity thereof;
- and
- selection of those previous images whose similarity measure relative to the representative image lies in a predetermined range around the similarity measure of the current image relative to the representative image,
- the image processing unit being arranged to associate with the current image that previous image from among the previous images whose phase of motion is closest to the phase of motion of the current image.
A method of associating a current image of a body volume which is subject to a motion comprising different phases of motion with one of several previous images of the body volume, in which method comprises the steps of:
- determining the phase of motion together with obtaining a set of relevant images;
- calculating a similarity measure between the current image and a representative image, the similarity measure being associated with the phase of motion;
- calculating the similarity measure between the representative image and the previous images or a sub-quantity thereof;
- and
- selecting those previous images whose similarity measure relative to the representative image lies in a predetermined range around the similarity measure of the current image relative to the representative image, wherein the current image is associated with that one of the previous images which has a phase of motion closest to the phase of motion of the current image.
An imaging device comprising:
- a controller for obtaining a current image of a body volume and a phase of motion of the body volume which belongs to the current image, the body volume being subject to a motion comprising cardiac and respiratory motion;
- and
- a memory in which previous images of the body volume are stored together with associated phases of motion,
- wherein the controller calculates first and second similarity measurements between the current image and the previous images, the first similarity measurement being associated with a phase of one of the cardiac or respiratory motions, the second similarity measurement being associated with a phase of the other of the cardiac or respiratory motions,
- wherein the controller selects a first sub-quantity of the previous images based on the first similarity measurement, and
- wherein the controller selects an image from the first sub-quantity based on the second similarity measurement.
Dependencies are inferred from the claim text.