Patent Description:
It is common practice that orthopedic surgeons and others perform geometric measurements in X-ray images. In a 2D X-ray image, the spatial information of the image object is reduced from three dimensions in reality to a 2D projection. The missing third dimension may limit quantitative analysis of the image content, e.g. in a geometrical sense. For example, quantitative measurements such as bone length measurements may be carried out. Instead of rough assessments, further X-ray image may be acquired from a different point of view to achieve three-dimensional image information in order to be able to achieve improved quantitative analysis. However, it has been shown that additional X-ray imaging may lead to an increased radiation dose and may also be cumbersome in the workflow.

<CIT> describes means for linking breast lesion locations across imaging studies. In particular, a generic three-dimensional representation of the female breast is used. Automatic translation of the lesion location into standard clinical terminology and aligning the breast model with individual patient images is comprised. Moreover, a mechanism for linking image locations showing a lesion to a location in the breast model is presented. If desired, a region of interest can be calculated by a region of interest definition module that predicts a region of interest of a known lesion in terms of the breast model representation in a new imaging study.

<CIT> relates to a method of adapting imaging parameters for a computer tomographic radiograph of a body volume, comprising the following steps: obtaining a three-dimensional pilot radiograph with a low dose of radiation; determining a region of interest and a desired image quality in the pilot radiograph with the aid of a patient model or interactively; determining optimal imaging parameters; generating an X-ray image using the determined imaging parameters. Optionally, the X-ray image is combined with the pilot radiograph.

There may be a need to provide an improved image processing.

The object of the present invention is solved by the subject-matter of the independent claims; further embodiments are incorporated in the dependent claims. It should be noted that the following described aspects of the invention apply also for the device for processing of an X-ray image of an object, for the X-ray imaging system, and for the method for processing of an X-ray image.

In an aspect, there is provided a device for processing an X-ray image of an object as defined in appended claim <NUM>.

In another aspect, there is provided an X-ray imaging system as defined in appended claim <NUM>.

In another aspect, there is provided a method for processing of an X-ray image of an object as defined in appended claim <NUM>.

In other aspects there is provided a computer program element and a computer readable medium as defined in appended claims <NUM> and <NUM>.

According to the disclosure, a device for processing of an X-ray image of an object is provided. The device comprises an input unit and a processing unit. The input unit is configured to provide a shape related information from an object to be irradiated, a generic object model and an actual X-ray image of the object. The processing unit is configured to adapt the generic object model based on the shape related information in order to generate an individual object model. The device determines, based on the individual object model, an individual image processing modificator for processing at least one part of the X-ray image and applies the individual image processing modificator for further processing of the X-ray image.

As a result, an improved geometry measurement in X-ray imaging is provided that allows an improved further processing of the image data.

The term "shape related information" can also be referred to as "depth related information".

The term "X-ray image" can also be referred to as "X-ray image data".

The term "individual object model" can also be referred to as an "adapted object model" or an "individually adapted object model".

The term "generic object model" can also be referred to as "generic object model data".

For example, the accuracy of bone length measurements is affected by uncertainties about the magnification factor which is due to the cone-beam geometry of the X-ray beam and the unknown distance of the bone to the detector plane.

Based on the X-ray image, one can scale stored 3D-data of an artificial numerical object in a way that this model comes close to the X-ray image data.

Based on this model, one can estimate at what distance to the detector the object has been.

The shape of high contrast object (e.g. bones) can be estimated locally and this information may be used for image (post-) processing, or image-modification, e.g. image enhancement or advanced scatter estimation with shape-adaptive scatter kernel.

According to an example, the processing unit is configured to convert X-ray image data in a predetermined area of the X-ray image into specific transmission values based on actually applied X-ray radiation parameters and to determine the shape related information based on the specific transmission values.

The term "X-ray radiation parameters" relates to, for example, settings applied for generating the X-ray radiation, such as voltage, current and time.

For example, the predetermined area is selected based on empirical data to provide an object area suitable for calculating a so-called water equivalent thickness.

According to an aspect, the shape information data is determined via a range measurement unit determining the actual distance of the object to the detector.

In an example, the range measurement unit is provided as a ruler.

The range measurement unit may also be provided as a laser rangefinder.

In an example, the range measurement unit may also be provided as a range camera.

According to an example, the device for processing of an X-ray image of an object further comprises an output unit. The output unit is configured to display a result of the further processing based on the applied individual image processing modificator for processing the X-ray image.

According to the disclosure, also an X-ray imaging system is provided. The X-ray imaging system comprises an X-ray imaging arrangement with an X-ray source and an X-ray detector and a device for processing of an X-ray image of an object according to one of the examples above. The X-ray imaging arrangement is provided to generate the actual X-ray image of the object arranged between the X-ray source and the X-ray detector.

In an example, the device for processing of an X-ray image of an object is configured to interpret the actual X-ray image.

The term "X-ray imaging system" can also be referred to as "Picture Archiving and Communication System (PACS)".

According to the disclosure, also a method for processing of an X-ray image of an object is provided.

According to an example, in step e), the individual image processing modificator comprises an image-modification, e.g. improved scatter correction.

In an example, the method is referred to as a method for image-modification, e.g. a method for scatter correction of an X-ray image.

According to an example, in step e), the further processing comprises an image interpretation, e.g. a feature analysis.

In an example, the method is referred to as a method for image interpretation, e.g. a method for feature analysis of an X-ray image.

In an example, the individual image processing modificator is adapted to modify the X-ray image.

In another example, the individual image processing modificator can also be referred to as correction factor, or as magnification factor, or as adjustment factor, or as adaption factor.

According to an example, for providing the shape related information, the following is provided:.

The shape related information is determined based on the specific transmission values.

In an example, the steps of the method for processing of an X-ray image of an object can also be referred to as:.

In an additional feature, the volume, weight or dimensions of the fitted artificial organ could be displayed.

<FIG> shows a device <NUM> for processing of an X-ray image of an object. The device comprises an input unit <NUM> and a processing unit <NUM>. In an option, the device <NUM> further comprises an output unit <NUM> (as indicated by a dashed separator line.

Also with reference to <FIG>, illustrating a flowchart in relation with an optional example, the input unit <NUM> is configured to provide a shape related information 16from an object <NUM> to be irradiated, and a generic object model <NUM>, and to provide an actual X-ray image <NUM> of the object. The processing unit <NUM> is configured to adapt the generic object model based on the shape related information <NUM> in order to generate an individual object model <NUM>. The processing unit <NUM> is configured to determine, based on the individual object model <NUM>, an individual image processing modificator <NUM> for processing at least one part of the X-ray image, and to apply the individual image processing modificator <NUM> for processing the X-ray image for feature analysis <NUM>.

In an option, the device <NUM> further comprises an output unit <NUM>. The output unit <NUM> is configured to display a modified X-ray image for feature analysis.

In an example not shown, the processing unit <NUM> is configured to convert image data in a predetermined area of the X-ray image <NUM> into specific transmission values based on actually applied X-ray radiation parameters. The processing unit <NUM> is also configured to determine the shape related information <NUM> based on the specific transmission values.

In another example not shown, the shape related information <NUM> is determined via a range measurement unit determining the actual distance of the object to the detector.

<FIG> shows two lateral views of patients, i.e. the object <NUM>, and an example of an X-ray detector <NUM>. The arrows indicate X-ray beams which pass through soft tissue layers of similar thickness in both cases, resulting in similar attenuation values. However, the lung volume of the patient on the left side is smaller than the lung volume of the patient on the right side.

<FIG> shows an X-ray imaging system <NUM> for imaging an object, for example a patient (indicated with numeral <NUM>). The system provides a space or region or area, in which the patient is arranged for imaging purposes. This space is referred to as an object receiving space <NUM>. The system further comprises an X-ray imaging arrangement with an X-ray source <NUM> and the X-ray detector <NUM>, and an example of the device <NUM> for processing of an X-ray image of an object.

The object receiving space <NUM> is arranged between the X-ray source <NUM> and the X-ray detector <NUM> to receive an object to be irradiated.

The X-ray imaging arrangement is provided to generate an actual X-ray image <NUM> of the object <NUM>, and the device <NUM> for processing of an X-ray image of an object <NUM> is configured to handle the actual X-ray image <NUM>.

The X-ray source <NUM> unit generates an X-ray beam to irradiate the object <NUM> to acquire an X-ray image <NUM> via the X-ray detector <NUM>.

The processing unit <NUM> creates an individual generic anatomical model which takes an actual distance of the source-side of the object to the object abutting surface into account to generate shape information <NUM> of the object to be irradiated.

<FIG> shows a flowchart of a further example for processing of an X-ray image <NUM> of an object. In an embodiment, shape related information <NUM> from an object sensor is combined with a generic object model <NUM> including organ models, and the acquired X-ray image <NUM>. An object modelling step uses the individual object model <NUM> and the X-ray image <NUM> to adapt the individual processing modificator <NUM>. The individual processing modificator <NUM> provides 3D information that can be used for advanced post-processing or modification tasks and/or interpretation, e.g. feature analysis <NUM>.

<FIG> shows a method <NUM> for processing of an X-ray image of an object, comprising the following steps. In a first set of steps <NUM>, <NUM>, also referred to as step a1) and a2), a shape related information <NUM> from an object <NUM> to be irradiated (a1) and generic object model data <NUM> (a2) are provided. In a second step <NUM>, also referred to as step b), the generic object model data <NUM>, is adapted, based on the shape related information, to generate an individual object model <NUM>. In a third step <NUM>, also referred to as step c), based on the individual object model <NUM>, an individual image processing modificator <NUM> for processing at least one part of an X-ray image <NUM> is determined. In a fourth step <NUM>, also referred to as step d), an actual X-ray image <NUM> of the object is provided. In a fifth step <NUM>, also referred to as step e), the individual image processing modificator for processing the X-ray image data for feature analysis is provided.

In an example, not shown, for providing the shape related information <NUM>, the method comprises the following steps:.

The shape related information <NUM> is determined based on the specific transmission values.

In another example, not shown, wherein, for providing the shape related information <NUM>, the following steps are provided:.

A range measurement unit is arranged to determine the distance between the source (<NUM>) and the object (<NUM>) to be irradiated.

In another example, not shown, the range measurement unit is configured as a stereo camera.

The computer program element might therefore be stored on a computer unit, which might also be part of an embodiment of the present invention. This computing unit may be adapted to perform or induce a performing of the steps of the method described above. Moreover, it may be adapted to operate the components of the above described apparatus. The computing unit can be adapted to operate automatically and/or to execute the orders of a user. The data processor may thus be equipped to carry out the method of the invention.

Claim 1:
A device (<NUM>) for processing of a 2D X-ray image (<NUM>) of an object (<NUM>), comprising:
- an input unit (<NUM>); and
- a processing unit (<NUM>);
wherein the input unit is configured to provide shape related information (<NUM>) from the object (<NUM>) to be irradiated, wherein the shape related information (<NUM>) is depth related information; and to provide a generic object model (<NUM>); and to provide the actual 2D X-ray image (<NUM>) of the object;
wherein the processing unit is configured to convert X-ray image data in a predetermined area of the 2D X-ray image (<NUM>) into specific transmission values based on actually applied X-ray radiation parameters; and the processing unit is configured to determine the shape related information (<NUM>) based on the specific transmission values, wherein the X-ray radiation parameters are settings applied for generating X-ray radiation used in acquisition of the actual 2D X-ray image (<NUM>), and wherein the shape related information (<NUM>) is water equivalent thickness;
wherein the processing unit is configured to segment organs in the 2D X-ray image (<NUM>), and wherein the organs comprises bones or lungs; wherein the processing unit is configured to adapt the generic object model (<NUM>) based on the shape related information in order to generate an individual object model (<NUM>), wherein the individual object model is a 3D model of the object and after the adaptation the individual object model (<NUM>) matches the 2D X-ray image (<NUM>) in terms of transmission and x and y dimensions of the segmented organs; and
wherein the processing unit is configured to determine, based on the individual object model (<NUM>), an estimation at what distance a detector was to the object in acquisition of the actual 2D X-ray image (<NUM>) and an individual image processing modificator (<NUM>) for processing at least one part of the 2D X-ray image (<NUM>); and the processing unit is configured to apply the individual image processing modificator (<NUM>) for processing of the 2D X-ray image (<NUM>) for feature analysis (<NUM>).