WO2017140744A1

WO2017140744A1 - X-ray stand height adjustment for increased view angle

Info

Publication number: WO2017140744A1
Application number: PCT/EP2017/053436
Authority: WO
Inventors: Tom VERZAAL
Original assignee: Koninklijke Philips N.V.
Priority date: 2016-02-17
Filing date: 2017-02-15
Publication date: 2017-08-24

Abstract

System (SIA) and related method for supporting operation of an imaging apparatus (IA). The system comprises an input port (IN) for receiving a request to perform a motion of an imaging component of an imaging apparatus (IA) towards an object or object support (TB). The imaging component (IC) is mounted at a height relative to said object or object support. An actuator control interface (ACI) is configured to issue a request to change said relative height so as to enable the said imaging component (IC) to perform the requested motion.

Description

X-ray stand height adjustment for increased view angle

FIELD OF THE INVENTION

The invention relates to a system for supporting operation of an imaging apparatus, to an imaging arrangement, to a method for supporting operation of an imaging apparatus, to a computer program element, and to a computer readable medium.

BACKGROUND OF THE INVENTION

Rotational x-ray equipment has become one of the main tools for treatment or diagnosis in the medical field. Thanks to advances in detector technology and others, modern x-ray equipment is capable of producing high quality imagery that allows better detection of ailments or safeguards interventions such as placements of catheters etc.

Unfortunately, despite these advances, some conditions, in particular in the cardio field, still go undetected.

SUMMARY OF THE INVENTION

There may therefore be a need for supporting imaging operation to at least partly address this need.

The object of the present invention is solved by the subject matter of the independent claims where further embodiments are incorporated in the dependent claims. It should be noted that the following described aspect of the invention equally applies to the imaging arrangement, to the method for supporting operation of an imaging apparatus, to the computer program element, and to the computer readable medium.

According to a first aspect of the invention there is provided a system for supporting operation of an imaging apparatus, comprising:

an input port for receiving a request to perform a motion of an imaging component of an imaging apparatus towards an object or object support (e.g. patient table), said imaging component comprising an x-ray source and an x-ray sensitive detector connected to respective ends of a C-arm structure, wherein the C-arm structure is mounted mounted at a height relative to said object or object support; and an actuator control interface configured to issue a request to change said relative height so as to enable/allow the said imaging component to perform the requested motion.

According to one embodiment, the system comprises a distance determiner capable of determining a distance between said imaging component and the object or object support (e.g., patient table), wherein said actuator issues the request if the determined distance is insufficient to accommodate the requested motion. In particular, changing the relative height can be understood as an "offset motion" and this is carried out only if the determined distance is insufficient to accommodate the requested motion. "Accommodating" as used herein means that the requested motion (in particular angulation) of the imaging component can be performed, in particular can be performed without collision. The "object" (to be imaged) includes in particular a human or animal patient or at least a part thereof.

For example, said change of the relative height allows achieving higher or steeper view angles, in particular C-arm angulation angles, than without said change in relative height. This allows acquiring more relevant imagery, in particular in cardio imaging.

According to one embodiment, the distance determiner determines said distance based on one or more readings from one or more proximity sensors.

Instead of, or in addition to using a proximity sensor, the distance determiner operates based on a geometric model of the object and/or the object support.

According to one embodiment, said motion comprises a rotation

("angulation") about an axis perpendicular to a longitudinal axis of the object or of the object support in an imaging region.

According to one embodiment, the issued request is to change the relative height by changing a height of the C-arm structure relative to ground. Alternatively or in conjunction, it is the height of the object support that is changed. For example, the object support height is maintained and it is only the height of the C-arm structure (relative ground) that is changed. In this case, no movement of the patient is required during a procedure.

According another aspect there is provided an imaging arrangement, comprising:

a system as described above; and

the imaging apparatus having the movable imaging component. According to yet another aspect there is provided a method for supporting operation of an imaging apparatus, comprising the steps of: receiving a request to perform a motion of an imaging component of an imaging apparatus towards an object or object table, said imaging component comprising an x-ray source and an x-ray sensitive detector connected to respective ends of a C-arm structure mounted at a height relative to said object or object table; and

changing said relative height so as to enable the said imaging component to perform the requested motion.

There may therefore be a need for a system and related method to improve the imaging capability of an x-ray imaging apparatus.

The proposed system helps to address these needs. It has been discovered by the applicant that especially in the cardio field, steep view angles provide useful imagery which allows the detection of a wide range of conditions. However, acquisition of cranial projections has been observed by the applicant to be particularly challenging in the case of obese or corpulent patients. The proposed system helps operating the x-ray apparatus to be able to acquire a wider range of steep view angle imagery, even for patients with challenging physical proportions. The proposed system obviates the need to re-design and to build imagers with enlarged gantries to accommodate for a patient population with increasing body measurement characteristics. Existing x-ray imagers designed for patient with smaller physical proportions can be used to increase ability to still acquire steeper view angle imagery. Of course the proposed system can also be used with benefit when imaging non- obese patients.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will now be described with reference to the following drawings (which are not necessarily to scale) wherein:

Figure 1 shows an imaging arrangement;

Figure 2 shows rotational movements of the imaging apparatus; and

Figure 3 shows a flow chart of a method for supporting operation of an imaging apparatus.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows a schematic diagram of an imaging arrangement IMA. The imaging arrangement IMA comprises a rotational x-ray apparatus ("imager") IA and a system SIA for supporting operation of imager IA. Turning first to the imager IA, this includes one or more imaging components IC. The imaging components include an x-ray source XR and an x-ray sensitive detector D. In one embodiment the rotational x-ray imager is of the C-arm or U-arm type. A combined imaging component is defined in these types of imagers where the x-ray source and the detector are connected in a stiff C-arm or U-arm structure. The C-arm CA is rotatably supported in a cradle structure CS.

As the name suggests, in these type of imagers the C-arm or U-arm is a gantry having the shape of a turned over letter "C" (or "U"). The imaging components, that is, the x- ray source XR and the detector D, are respectively, connected to the respective ends of the C- arm. In this manner the gantry CA embraces at least partly an imaging region and has the x- ray source and the detector arranged in opposed relationship across said imaging region.

The imaging arrangement IA further includes in one embodiment an object support, such as a patient table TB. The object support supports an object to be imaged during the imaging procedure. In one embodiment, but not necessarily all embodiments, a medical context is envisaged where the "object" is a patient PAT or at least a part of the patient's anatomy. Human or animal patients are envisaged herein. The object however may also be inanimate such as an item of baggage in screening applications or the object may be a sample in non-destructive application, etc. Although in the following we will refer mainly to the medical context, this is not to exclude these (and other) non-medical contexts.

The image apparatus IA in Figure 1 shows a mobile solution with the cradle structure mounted in a moveable dolly structure DL. However this is exemplary, as fixed solutions are also envisaged where the C-arm is rotatably ceiling, floor or wall mounted or mounted on a cradle fixedly connected to the ground GR of the imaging venue (examination room, etc.).

The imaging apparatus enjoys a number of different mechanical degrees of freedom to help a user achieve best imaging results ("user" we refer to the person operating the imager). For instance, and as shown in Figure 1, the combined imaging component (that is, the C-arm with the source XR and detector D connected therein) is rotatable not only about a single, but two or more rotation axes although embodiments with a single rotational degree of freedom are not excluded herein.

One rotation axis is shown in Figure 1 as a dashed line. It allows rotation essentially about the longitudinal axis of the patient when lying on the patient table TB. This first rotation is indicated by C2 in the Figure. There is also another rotation envisaged herein referred to in the following as "angulation". This rotation is around an axis which extends perpendicular into the plane of the drawing of Figure 1. That is, the axis for the angulation is perpendicular to the

longitudinal axis of the patient. The angulation is shown as CI. In addition to having the one or more rotation axis, the cradle structure is height adjustable relative to ground GR.

The adjustable height is shown in the Figure as HI . Other translation options are also included and envisaged in other embodiments. In one, but not necessarily all embodiments, it is also or instead the table TB that is height adjustable. The adjustable table height is shown as H2 in Figure 1.

The respective translations or rotations (in particular the angulation) is brought about by suitable actuators (not shown) such as stepper motors or servo motors suitable arranged and controlled from an operator console CON. The console CON includes one or more user control interfaces such as a joystick, foot pedal or other. When the user, such as an interventional radiologist, operates the user interface of the console, a series of commands are issued. These are translated into electrical control signals with which the various actuators can be controlled and adjusted. The control signals are schematically shown as Tk, Hj and Q in Figure 1.

The control signals correspond to requests for a certain imaging geometry. By the term "imaging geometry" is meant the specific spatial configuration between the imaging components and the patient. The imaging geometry can be changed by rotating the C-arm around the one or more axis, in particular by angulation and/or by changing the image component height HI relative ground. In addition, or instead to a change of imaging component height HI, the table height H2 can be requested to change along direction Tl. The table may also be advanced in a (horizontal) plane as shown as T2.

Broadly, during the imaging procedure, the user requests a certain imaging geometry by operating the console and issues the control signals to the respective actuators. In response thereto it is in particular the C-arm's angulation and/or height that are adjusted to achieve the best possible view of the anatomy of interest. Once the desired imaging geometry is assumed, that is, once the C-arm has moved into place, the x-ray source is operated to emit an x-ray radiation beam which passes through the anatomy of interest. The x-ray beam interacts with matter in the anatomy. The interacting x-ray emerges at the far end (relative to the x-ray source) from the patient and then impinges on an x-ray sensitive surface of the detector D. The surface is made up from detector pixels. These respond to the impinging radiation by generating a spatially corresponding image signal. The image signals are captured by data acquisition circuitry which includes in particular an analogue to digital converter stage to produce imagery which can be viewed on one or two monitors MT.

It emerged that for certain imaging tasks, such as in cardio-imaging, it is desirable to acquire imagery at steep or high view angles. The notion of steep or high view angles can best be explained with reference to the geometry as per Figure 1. There is an imaginary line called an optical axis which can be thought to extend from a focal point of the X-ray source to a central portion of the detector. The optical axis will change in space if the imaging geometry, in particular the C-arm, rotates. The optical axis in general intersects the longitudinal axis of the patient at an intersection angle: the smaller the intersection angle, the steeper or higher the view angle. Another way to parameterize the cranial view angle is to define cranial (viewing) angle= +/-(90°- "intersection angle"). The smallest intersection angle is 0° so the highest or steepest possible cranial view angle is hence 90° at which point the imaging axis and the longitudinal axis are parallel, which is, of course, not achievable, unless the C-arm diameter is larger than the table length. The signum +/- indicates clockwise and counterclockwise angulation. A view angle > 25° would be considered steep or high, both terms being used interchangeably herein. In one case the X-ray source is above the table, in the other the X-ray source is under table level. Acquiring imagery at as steep as possible projection/view angle allows acquiring cranial projection imagery. This is particularly useful in cardio imaging where, prior to administration of contrast agent, the heart vessel structures can be seen, which has in this projection view a "spider"-like appearance.

As can be seen from the C-arm geometry in Figure 1, because the C-arm partially embraces the patient table, the ability to acquire arbitrary steep imagery is restricted, even more so, when one deals with corpulent patients who, by definition, have a larger extension in horizontal or y direction when supine. Specifically, because of the imaging components IC are mounted to the C-arm CA and because of the CA partly embracing a part of the table (with the patient on it), it is seen that in an angulation one of the imaging components IC is moved towards the patient/table from above or below. In other words, the angulation causes a distance between one of the imaging components and the table/patient to decrease. Such decrease in distance does not occur in rotations C2 around the longitudinal axis of patient or table. Figure 2A is an illustration of this. One of the imaging components, in this case the x-ray source XR, will collide with either patient or table, if too steep a projection angle is requested by the user. This is where the proposed imaging support system SIA comes in to support imaging. The upper right of Figure 1 shows a close up of components of the imaging support system SIA as proposed herein.

Broadly, the action of the imaging support system SIA is schematically shown in Figure 2B. If the user requests, by operation of the console for instance, too steep a projection angle (that is, one that would lead to a collision with patient or table), the support system SIA issues a suitable control signal to effect a suitable change of the imaging geometry to make space so that the requested angulation can be performed. This change in geometry may be effected by carrying out an offset motion. In a preferred embodiment the offset motion is as shown in Figure 2B by the hatched upwards arrow. In other words, the height HI of the C-arm is dynamically changed and hence that of the x-ray source and/or the detector. Because of this height adjustment the (clockwise) angulation (shown as the hatched curved arrow) can be increased as shown by the curved hatched arrow, to so achieve a higher view angle. In a similar manner, a steeper angle can also be achieved by an angulation in counter clockwise direction. In this case the imaging support system SIA will instruct the C- arm to decrease its height HI relative ground GR.

The offset motion for the purposes of achieving steeper view angles can also be achieved by changing instead (or in addition to the C-arm height) the height of the table H2. For instance, in the same situation in Figure 2B, the offset motion can be achieved by leaving the C-arm at a constant height HI but by lowering the table height H2.

The offset motion of the table or the C-arm/imaging component for accommodating increased range of angulation, can be realized concurrently with said angulation or these motions are carried out in sequence. For instance, it is first the C-arm height or table height that is adjusted and then the angulation is carried out to achieve the required steep projection angle. Preferably, however, both of the two motions (angulation and offset motion) are at least party concurrently adjusted so as to achieve a "fluid" or smooth change of the imaging geometry. This saves time. Preferably, the requested angulation is slightly delayed to give the offset motion a head start or the offset motion is carried out with greater speed than the requested angulation. Movement of C-arm instead of table height movement is the preferred embodiment, as medical personnel can continue work largely undisturbed which is likely not the case in table height changes as will also impact on medical equipment (catheters, etc.) in place.

Operation of the imaging support system SIA is now explained in more detail with continued reference to the close-up in the upper right hand of Figure 1. The system includes an input port LN, a distance determiner DD and an actuator control interface ACL A request for an imaging geometry change is received at input port IN of the system SIA. This request includes in particular a request for an angulation to achieve a steeper view angle. The request is either the control signal itself or, on a higher level, a corresponding command.

Based on a current imaging geometry, the distance determiner determines the (spatial 3D) distance between the table and/or the patient and one of the imaging

components. The distance may for example be determined for one or more points along a trajectory of the requested motion of the imaging component. It is then established via geometrical computation by the distance determiner DD whether the requested angulation can be accommodated spatially. In other words it is determined whether there is sufficient distance, given the current imaging geometry, for the requested motion, for example an angulation to a relatively steep viewing angle, to be performed, without any risk of collision between the imaging components and the patient or the patient table. For example, a collision between the X-ray detector D and the patient should be avoided.

A typical cranial view angle achievable in current C-system is 25-30°. In the proposed system, an angulation with a relatively steep viewing angle of for example more than 30° can be performed. For example, cranial angles of 40-45° are achievable thus substantially increasing the chances of detecting heart conditions in even corpulent patients.

If yes, the actuator control system is instructed to issue suitable commands to the actuator of the imaging apparatus to effect the requested angulation. If however, the distance determiner determines that the requested angulation would result in a collision because there is insufficient distance, an off-set value Δ to the relative height between C-arm and patient or patient support is computed, that quantifies the required offset in relative height so as to enable the requested angulation without inflicting a collision.

The off-set value can either specify the change in table height H2 and/or a change of C-arm height HI versus ground GR. What matters herein, is that the relative height between the table H2 and the height of the C-arm HI is so adjusted that the requested angulation can be carried out. From a medical point of view for example the table height H2 may be left unchanged during the imaging while the C-arm height HI is changed to achieve the necessary off-set Δ. Once it is established there is insufficient space/distance between at least one imaging component (source XR or detector D) and the table/patient, the offset motion is effected via the actuator control interface ACI, in other words the C-arm height is changed and/or the table height is changed. After or concurrently with carrying out the offset motion via the actuator control interface ACI, the angulation is carried out via a

corresponding actuator control interface.

The computation by the distance determiner of the current distance between patient/table and an imaging component can either be based on physical measurement as acquired by one or more proximity sensors (as an example, three are shown in Figure 1 as PS1-PS3) or this distance is determined purely geometrically based on a geometric model of the imaging model and the patient. The geometrical model can be obtained by acquiring an optical or depth sensing "model image" for instance of the supine patient prior to the X-ray imaging. The model image can then be translated by a suitable CAD module into a mesh model. The mesh model is then spatially registered with a coordinate system of the imaging geometry of the imager.

Because the imaging system is always "aware" of its own geometry by virtue of the actuator settings, this geometrical knowledge can be combined with the mesh model of the patient to form a combined "patient +table" model that encodes all relevant geometrical relationships. It is then a matter of relatively straight-forward geometrical computations to establish whether the current distance between the imaging component and the patient or table is sufficient to accommodate the requested angulation. This current distance may instead be determined based on proximity sensors suitably arranged at the imaging components. Depending on how many proximity sensors PSj are used and depending on where they are located, no 3D model is required and the imaging component-table (or patient on table) distance d can be determined solely from readings received from the sensor(s) PSj. Specifically, if two proximity sensors PSl, PS2 are used and these are located on the C-arm (specifically, on the respective imaging components) as shown in Fig. 1, then the

determination on whether the distance is sufficient or not is possible without model. The preferred locations are at or around a forward edge (proximal to the table TB) of a housing of the X-ray unit XR as indicated for sensor PS 1 in Figure 1. In addition, a sensor PS2 may be located on a corresponding edge of the detector D housing, that is, on or around the edge proximal to the table TB.

The 3D model is required however in case the proximity sensor at PS 1 and/or PS2 is removed. Preferably however, a proximity sensor is located as explained above for proximity sensor PSl. The proximity sensor PS2 at the shown location, that is, at the imaging component that is mainly located under the table TB, can be dispensed with and can be replaced by a 3D model of the table structure, since in this location typically only equipment collisions occur. Geometrically, the check whether there is sufficient distance to accommodate in the requested angulation, is then essentially a question of geometrical intersection. For instance, the patient+table model has a surface which can be defined in terms of geometrical coordinates. If a geometrical point on any of the imaging components comes to lie on or within said surface, if one were to perform the requested angulation, this is an indication that there will be collision and thus the angulation cannot be accommodated by the current imaging geometry. It will be understood that the angulation itself will not be performed physically, but is (first) merely simulated geometrically and the above described checks on whether the current imaging geometry can accommodate the requested angulation is done purely numerically/geometrically. Only after the computations reveal that the angulation can in fact be accommodated, is the angulation performed physically. The distance between the table or the patient or the patient-table system can be computed relative to any chosen reference point. For instance, an outer lower edge of the detector housing or the x-ray source housing can be used.

In sum, the imaging support system SIA as proposed herein has a "guard function" and is interposed between the console CON and the imager actuator control circuit. It intercepts user requests for imaging geometry changes issued from the console CON and checks whether an angulation is requested, and if yes whether this can be geometrically accommodated given the current imaging geometry. If it can be accommodated, the requested angulation is carried out. If the angulation cannot be accommodated because the distance between the respective imaging component IC and i) the table or ii) patient on the table is insufficient, the offset motion is carried out. After conclusion of the offset motion or (at least partly) concurrently with carrying out the offset motion, the requested angulation is carried out.

Some or all components of the imaging support system SIA can be

implemented purely as software and can be run on a general purpose computer PU.

Alternatively, all or some of the components are realized as a micro controller in an integrated circuit. Specifically, an integrated circuit with an SOC (system-on-chip) architecture can be used. The SIA circuity is either hardwired or customizable, such as in an FPGA (field-programmable-gate-array). All these embodiments are envisaged herein. In one embodiment the imaging support system SIA is fully integrated into the circuitry of the operator console CON.

As mentioned, one or more sets of proximity sensors can be used suitably placed on the C-arm imaging component, or indeed the patient or the table. Any type of proximity sensors can be used herein, for instance, those of capacitive type, infrared sensor or others. Preferably, however, capacitive type proximity sensors are used as they allow achieving high measuring accuracy.

Reference is now made to Figure 3, which shows a flow chart for a method for supporting operation of an imaging apparatus. The method steps described in the following are not necessarily tied to the architecture as shown in Figure 1. The following description of the method constitutes therefore a teaching in its own right.

At step S310 a request to perform a motion of an imaging component of an imaging apparatus is received. The requested motion involves an angulation of a gantry carrying the imaging component(s). The angulation would result in at least one of the imaging components moving towards a patient or patient table residing in an imaging region around which the imaging component is rotatable.

At step S320 a current distance d between said imaging component and the patient or patient table is determined. This distance can be computed by using proximity sensors and/or by using a geometrical model of the patient and/or patient+table registered in relation to the current imaging geometry. For instance the current imaging geometry and geometrical model can be aligned in a common co-ordinate system. Based on the so determined distance, it is then determined whether the requested change of angulation can be spatially accommodated, in particular without incurring a collision.

If no collision is expected, that is, if there is sufficient distance d, method flow passes on to step S325 to realize, by controlling suitable actuators, the requested motion (including the angulation) of the imaging component.

If, however, it is determined at step S320 that the distance d is insufficient, that is, the distance d is such that the requested motion by at least one of the imaging components would result in a collision between the respective imaging component and the patient or table, an off-set quantity is computed. The off-set quantity specifies the offset motion (magnitude and direction: up or down) of the required relative change in height between the patient and/or patient table and the relevant imaging component. In particular the smallest such height is determined plus possibly an applicable error margin.

Method flow then passes on to step S330 where the computed offset motion, that is, the change in relative height is effected so as to geometrically allow or enable the requested imaging component motion (e.g. angulation) to be performed. The distance computation and the determination whether the requested motion can be accommodated, is carried out based on physical measurements by sensor(s), such as proximity sensors, or may be computed purely theoretically or geometrically by using a geometrical model of the imaging geometry aligned with a geometric model of the patient and/or table. A combination of using sensors and the model is also envisaged.

Although the above has been explained largely for angulations, other motions or motion combinations that can be enabled by changing the relative height between at least one imaging component and the object support (e.g. table) are also envisaged herein.

In another exemplary embodiment of the present invention, a computer program or a computer program element is provided comprising instructions which, when executed on a processing unit, may cause an appropriate system to carry out the steps of the method according to one of the preceding embodiments.

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. A computer program may be loaded into a working memory of a data processor. The data processor may thus be equipped to carry out the method of the invention.

This exemplary embodiment of the invention covers both, a computer program that right from the beginning uses the invention and a computer program that by means of an up-date turns an existing program into a program that uses the invention.

Further on, the computer program element might be able to provide all necessary steps to fulfill the procedure of an exemplary embodiment of the method as described above.

According to a further exemplary embodiment of the present invention, a computer readable medium, such as a CD-ROM, is presented wherein the computer readable medium has a computer program element stored on it which computer program element is described by the preceding section.

A computer program may be stored and/or distributed on a suitable medium (in particular, but not necessarily, a non-transitory medium), such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems.

However, the computer program may also be presented over a network like the World Wide Web and can be downloaded into the working memory of a data processor from such a network. According to a further exemplary embodiment of the present invention, a medium for making a computer program element available for downloading is provided, which computer program element is arranged to perform a method according to one of the previously described embodiments of the invention.

It has to be noted that embodiments of the invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the device type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application.

However, all features can be combined providing synergetic effects that are more than the simple summation of the features.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A system (SIA) for supporting operation of an imaging apparatus, comprising:

an input port (IN) for receiving a request to perform a motion of an imaging component of an imaging apparatus (IA) towards an object (PAT) or object support (TB), said imaging component (IC) comprising an x-ray source (XR) and an x-ray sensitive detector (D) connected to respective ends of a C-arm structure (CA), wherein the C-arm structure is mounted at a height relative to said object (PAT) or object support (TB); and an actuator control interface (ACI) configured to issue a request to change said relative height so as to enable the said imaging component (IC) to perform the requested motion.

2. System of claim 1, comprising a distance determiner (DD) capable of determining a distance between said imaging component (IC) and the object or object table, wherein said actuator control interface (ACI) issues the request if the determined distance is insufficient to accommodate the requested motion.

3. System of claim 2, wherein the distance determiner (DD) determines said distance based on one or more readings from one or more proximity sensors (PS1-PS3).

4. System of any one of claims 2-3, wherein the distance determiner (DD) operates based on a geometric model of the object and/or the object support.

5. System of any one of the previous claims, wherein said motion comprises a rotation about an axis perpendicular to a longitudinal axis of the object or object support.

6. System of claim 5, wherein said motion is a C-arm angulation to a relatively steep cranial viewing angle.

7. System of any one of the previous claims, wherein the issued request is to change the relative height by changing at least one of aheight (HI) of the C-arm structure and a height (H2) of the object support (TB), relative to ground (GR).

8. Imaging arrangement (IMA), comprising:

a system (SIA) as per any one of the previous claims; and

the imaging apparatus (IA) having the movable imaging component (IC).

9. A method for supporting operation of an imaging apparatus, comprising the steps of:

receiving (S310) a request to perform a motion of an imaging component of an imaging apparatus towards an object or object table, said imaging component (IC) comprising an x-ray source (XR) and an x-ray sensitive detector (D) connected to respective ends of a C-arm structure (CA) mounted at a height relative to said object or object table; and changing (S330) said relative height so as to enable the said imaging component (IC) to perform the requested motion.

10. A computer program element comprising instructions which, when executed on a processing unit (PU), cause an imaging arrangement to perform the method steps of claim 9.

11. A computer readable medium having stored thereon the program element of claim 10.