DE102011086286A1 - Method for analyzing angiology of patient by computer, involves receiving three-dimensional space-resolved volume-image of angiology by computer, where computer divides angiology into sections - Google Patents

Abstract

The method involves receiving a three-dimensional space-resolved volume-image (4) of angiology by a computer (1). The computer divides the angiology into sections. The determined sections are limited in branching-free and one or both sides of a nodal point by the computer. The nodal point is adjacent to the three determined sections of the computer. An independent claim is included for a computer program with a machine code.

Description

• – wobei der Rechner ein dreidimensional ortsaufgelöstes Volumenbild des Blutgefäßsystems entgegen nimmt,
• – wobei der Rechner das Blutgefäßsystem in Abschnitte unterteilt,
• – wobei die vom Rechner ermittelten Abschnitte jeweils in sich verzweigungsfrei sind und einseitig oder beidseitig von einem Knotenpunkt begrenzt sind,
• – wobei die Knotenpunkte jeweils an mindestens drei der vom Rechner ermittelten Abschnitte angrenzen,
• – wobei der Rechner für die Abschnitte jeweils eine auf den jeweiligen Abschnitt bezogene Abschnittssegmentierung des Blutgefäßsystems in dem dreidimensional ortsaufgelösten Volumenbild ermittelt und
• – wobei die Überlagerung der Abschnittssegmentierungen einer Gesamtsegmentierung des Blutgefäßsystems entspricht.

The present invention relates to an evaluation method for a blood vessel system of a patient by a computer,

• The computer receives a three-dimensional spatially resolved volume image of the blood vessel system,
• Wherein the computer divides the blood vessel system into sections,
• Wherein the sections determined by the computer are in each case branch-free and are bounded on one or both sides by a node,
• Wherein the nodes each adjoin at least three of the sections determined by the computer,
• - Wherein the computer for the sections in each case a related to the respective section section segmentation of the blood vessel system in the three-dimensional spatially resolved volume image determined and
• - wherein the superposition of the segment segmentations corresponds to a total segmentation of the blood vessel system.

The present invention further relates to a computer program which comprises machine code which can be processed directly by a computer and whose execution by the computer causes the computer to carry out such an evaluation method.

The present invention further relates to a computer, wherein the computer is designed such that it performs such an evaluation method during operation.

• – das automatische Vermessen von räumlichen Größen eines Aneurysmas (beispielsweise Volumen, Durchmesser, Ostiumweite),
• – CFD-Flusssimulationen mit und ohne Aneurysma,
• – Auflösen des Kissing-Vessel-Problems und
• – das automatische Detektieren der Aneurysmenöffnung, welche dann für weitere CFD-Analysen verwendet werden kann.

In the computer-aided evaluation of blood vessel systems often not only pure visualizations should be made. Rather, more extensive evaluations, such as the determination of dimensions and dimensional ratios or blood flow simulations, are often to be carried out. Furthermore, modifications of the computer-aided ascertained blood vessel system should often be made and assessed. In particular, it should be possible to hide individual vascular branches or malformations of the blood vessel system and to disregard them during the evaluation or to subsequently correct connections of blood vessel systems that can not be resolved by the imaging (= segmentation). Possible applications in which such manipulations of the blood vessel system may be useful are, for example

• The automatic measurement of spatial sizes of an aneurysm (for example, volume, diameter, ostium width),
• - CFD flow simulations with and without aneurysm,
• - Resolving the Kissing Vessel Problem and
• The automatic detection of the aneurysm opening, which can then be used for further CFD analyzes.

Aneurysms are pathological changes of a vessel section. They are usually in the form of a pathological, localized, often baggy extension of a blood vessel. In particular, an aneurysm can occur in a blood vessel in the region of the brain or of the heart. The clinical significance of an aneurysm, which is localized, for example, in the brain, in particular due to the risk of rupture, so a crack or fracture, which can lead to bleeding and thrombosis, for example, in extreme cases to stroke.

The dynamics of blood flow in an aneurysm is often considered in today's medicine as an important factor for the pathogenesis of the aneurysm, thus for its formation and development. Important prognostic factors include the geometric sizes of the aneurysm and hemodynamic parameters that define blood flow. Hemodynamic parameters are determined in particular by means of CFD (= computational fluid dynamics). Such methods simulate blood flow in a vessel section.

From the technical essay "Hemodynamics in a Cerebral Artery before and After the Formation of Aneurysm" by A. Mantha et al., American Journal of Neuroradiology (2006), Number 27, pages 1113 to 1118 It is known to bring a number of so-called hemodynamic parameters associated with growth and rupture of the aneurysm. In the context of this technical article, a hemodynamic parameter is to be understood in particular to mean a parameter which relates to hemodynamics, that is to say a flow mechanics of the blood. The hemodynamic parameters mentioned in the abovementioned technical article include, inter alia, a shear stress (WSS) relating to the vessel wall and a flow rate. For example, in order to conclude such hemodynamic parameters, blood flow in a vascular segment comprising the aneurysm is simulated once with aneurysm and once with digitally removed aneurysm. The two simulations are compared.

In the paper "Computer aided Planning for Endovascular Treatment of Intracranial Aneurysm (CAPETA)" of A. Mohamed et al., Medical Imaging 2010: Visualization, Image-Guided Procedures and Modeling, Proc. of SPIE, Vol. 7625, 2010, pages 1 to 9 , a method is described which can be used to virtually separate an aneurysm from the rest of the vasculature. However, the remaining vascular system does not correspond to a natural vessel of origin and therefore, for example, can not usefully be used for CFD blood flow simulation.

In the technical essay "An objective approach to digital removal of saccular aneurysms: Technique and applications" of MD Ford et al., British Journal of Radiology, January 1, 2009, 82 (Special Issue 1), pages 55 to 61 , the separation of the aneurysm is performed by means of a Voronoidiagramms, which is calculated there on the network surface, ie on the segmentation result of the original three-dimensional data, which has been converted into a network. Since this paper only works on the network interfaces, there is no feedback on the original data set. It is therefore possible that important information for modeling is ignored or that errors in the segmentation are included in the vessel reconstruction.

In general, although the approaches known in the prior art allow automatic digital removal of aneurysms from the vessel. However, they have individual limitations. Furthermore, none of the approaches of the prior art allows easy selection and selection of vessels. Also, the prior art does not allow the solution of the so-called Kissing Vessel problem.

The object of the present invention is to create possibilities by means of which touching vessels can be described as such, the connection between the different vessel segments can be reversed in a simple manner and, if appropriate, the vessels can be reconstructed as realistically as possible. Furthermore, for example, in the case of an aneurysm, the aneurysm should be virtually separated from the remaining blood vessel system and the original course of the vessel reconstructed as realistically as possible. As a result, the object of the present invention is thus to provide possibilities which make it possible for the different aneurysms and branching vessels to identify them in a simple manner and to remove them automatically or at least semi-automatically.

The object is achieved by an evaluation method having the features of claim 1. Advantageous embodiments of the evaluation method according to the invention are the subject of the dependent claims 2 to 15.

• – dass der Rechner die ermittelten Abschnittssegmentierungen dem jeweiligen Abschnitt zuordnet, so dass bei Anwahl eines bestimmten Abschnitts die zugehörige Abschnittssegmentierung direkt bestimmt ist, und
• – dass der Rechner, ausgehend von den ermittelten Abschnitten und den den Abschnitten zugeordneten Abschnittssegmentierungen, weitere Maßnahmen ergreift.

According to the invention, it is provided

• - That the computer assigns the determined segment segmentation to the respective section, so that when selecting a particular section, the associated section segmentation is determined directly, and
• - That the computer, taking on the basis of the determined sections and the sections associated with sections segmentation, take further action.

In particular, this makes it possible to carry out individual manipulations of the (virtual) blood vessel system quickly and easily.

Thus, it is possible, for example, for the user to interactively and reversibly specify a section in another node that divides two new sections in addition to the nodes determined by the computer in the context of the subdivision of the blood vessel system into sections.

Furthermore, it is possible for the user to specify additional sections interactively and reversibly by the user in addition to the sections determined by the computer within the scope of the division of the blood vessel system into sections. In this case, it is alternatively possible to directly specify a section and subsequently automatically generate the associated nodes. Alternatively, this procedure can be configured such that the user first has to specify the node or the nodes of the further section and only then can specify the further section.

Likewise, it is possible for the computer to specify for each of the sections whether the respective section is activated or deactivated, and that the computer only overlays the activated sections when superposing the section segmentations for the overall segmentation and / or within the scope of the further measures considered.

For example, in the event that the user deactivates a section that is bounded on one side only by a node, it is possible for the computer to automatically check whether the node delimiting the deactivated section still limits at least three activated sections and, if so, the corresponding one Disabled node, the two still limited by the corresponding node activated sections combined into a common section and redetermined for the common section section segmentation and assigns the common section.

Analogously, it is possible that in the case that the user deactivates a section, which is bounded on both sides by a node, the computer automatically checks for both the deactivated section limiting nodes, whether they each still at least three activated sections limit, and if necessary, the respective node disabled, the still limited by the respective node activated sections to a respective common Summarized section and reassigned for the respective common section, the respective segment segmentation and assigns the respective common section.

• – bei dem Anwender nachfragt, ob ausgehend von dem deaktivierten Abschnitt alle nachfolgenden oder vorausgehenden Knotenpunkte und Abschnitte deaktiviert werden sollen,
• – bejahendenfalls die entsprechenden Knotenpunkte und Abschnitte deaktiviert, selbsttätig prüft, ob der andere den deaktivierten Abschnitt begrenzende Knotenpunkt noch mindestens drei aktivierte Abschnitte begrenzt, und verneinendenfalls den anderen Knotenpunkt deaktiviert, die beiden noch von dem anderen Knotenpunkt begrenzten aktivierten Abschnitte zu einem gemeinsamen Abschnitt zusammenfasst und für den gemeinsamen Abschnitt die Abschnittssegmentierung neu ermittelt und dem gemeinsamen Abschnitt zuordnet, und
• – verneinendenfalls für beide den deaktivierten Abschnitt begrenzenden Knotenpunkte selbsttätig prüft, ob sie jeweils noch mindestens drei aktivierte Abschnitte begrenzen, und verneinendenfalls den jeweiligen Knotenpunkt deaktiviert, die noch von dem jeweiligen Knotenpunkt begrenzten aktivierten Abschnitte zu einem jeweiligen gemeinsamen Abschnitt zusammenfasst und für den jeweiligen gemeinsamen Abschnitt die jeweilige Abschnittssegmentierung neu ermittelt und dem jeweiligen gemeinsamen Abschnitt zuordnet.

However, in the case where the user deactivates a section bounded on both sides by a node, it is preferred that the computer

• Asking the user whether all subsequent or preceding nodes and sections should be deactivated starting from the deactivated section,
• If so, deactivates the corresponding nodes and sections, automatically checks whether the other node delimiting the deactivated section still delimits at least three activated sections and, if so, deactivates the other node, combines the two activated sections delimited by the other node into a common section, and for the common section, recalculate the section segmentation and assign it to the common section, and
• - If the case is negative, for both nodes bounding the deactivated section, it automatically checks whether they each still delimit at least three activated sections and, if appropriate, deactivates the respective node which combines activated sections bounded by the respective node to a respective common section and for the respective common section redetermines the respective section segmentation and assigns it to the respective common section.

Within the scope of the subdivision of the blood vessel system into sections, it is possible, for example, for the computer to determine the central lines of the sections in the volume image and to take into account the course of the respective central line in the course of determining the segment segmentations.

• – entlang der Zentrallinien Stützstellen setzt,
• – für die Stützstellen gemäß vordefinierter Optimierungsbedingungen jeweils eine Parametrierung eines parametrierbaren Volumenobjekts ermittelt,
• – das mit der jeweils ermittelten Parametrierung parametrierte Volumenobjekt der jeweiligen Stützstelle zuordnet und
• – die jeweilige Abschnittssegmentierung anhand der Überlagerung der parametrierten Volumenobjekte der in dem jeweiligen Abschnitt gelegenen Stützstellen ermittelt.

In particular, it is possible that the computer in the context of determining the segment segmentation

• - sets support points along the central lines,
• A parameterization of a parameterizable volume object is determined in each case for the interpolation points in accordance with predefined optimization conditions,
• - assigns the volume object parameterized with the respectively determined parameterization to the respective interpolation point and
• The respective segment segmentation is determined on the basis of the superimposition of the parameterized volume objects of the interpolation points located in the respective section.

The parameterizations may include, for example, location, orientation and dimensions of the parameterizable volume object. Furthermore, the parameterizable volume objects can be ellipsoids.

The further measures may include a blood flow simulation. Alternatively or additionally, the further measures can detect a determination of geometric dimensions and / or dimensional ratios of the blood vessel system.

In the event that the determined geometric dimensions and / or dimensional ratios of the blood vessel system violate a predefined condition, the further measures can in particular capture an automatic information of a user about this. Also, the location of the blood vessel system, where the predefined condition is violated, can be automatically marked by the computer in a representation of the blood vessel system.

The object is further achieved by a computer program of the type mentioned. The computer program is designed in this case such that the processing of the machine code by the computer causes the computer to carry out an inventive evaluation method.

The object is further achieved by a computer which is designed such that it performs an inventive evaluation method during operation.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments, which will be described in more detail in conjunction with the drawings. This show in a schematic representation

1 a block diagram of an evaluation arrangement,

2 a flow chart,

3 a volume image of a blood vessel system,

4 and 5 each a section of the blood vessel system in two-dimensional representation,

6 a modification of 5 .

7 a flow chart,

s 8th and nine Modifications of the blood vessel system of 3 .

10 a flow chart,

11 a modification of the blood vessel system of 3 .

12 a flow chart,

13 a modification of the blood vessel system of 3 .

14 a flow chart,

15 a section of the blood vessel system,

16 a flow chart and

17 a modification of the blood vessel system of 3 ,

According to 1 is a calculator 1 with a computer program 2 programmed. The computer program 2 includes machine code 3 that from the calculator 1 is directly workable. The execution of the machine code 3 through the computer program 2 programmed calculator 1 causes the calculator 1 performs an evaluation procedure in operation, which is described below in connection with 2 is explained in more detail.

According to 2 takes the calculator 1 in a step S1, a volume image 4 opposite. The volume image 4 is three-dimensional spatially resolved. For example, it may have 300 × 400 × 500 voxels. Other resolutions are possible, for example 512 × 512 × 512 voxels. The volume image 4 shows according to 3 the blood vessel system 5 a patient. The volume image 4 can for example be prepared in advance on the basis of projection images, which are detected by means of an X-ray system (C-arm or CT). As such, the projection images may be DSA images. Other types of data acquisition are possible, for example by means of a magnetic resonance system.

In one step S2 the computer divides the blood vessel system 5 into individual sections 6 - please refer 3 , The sections 6 are in 3 (and also in some of the other figure) partially additionally provided with small letters, so for example as a section 6a . 6b . 6c etc. referred to. However, this distinction is only to illustrate the invention, if in the figures, various sections 6 must be distinguished from each other. The addition of the respective lowercase letters in the figures is still consistent for all figures. For example, the section corresponds 6a in 3 with the section 6a in other figures.

The individual sections 6 are according to 3 each without branching, thus have two ends and between the two ends no branching. You can - see for example the section 6a in 3 - one-sided from a node 7 be limited. Alternatively, the sections 6 - see for example the section 6b in 3 - on both sides of a node 7 be limited. The nodes 7 are defined by the fact that the blood vessel system 5 at the intersections 7 splits. The nodes 7 thus each border on at least three sections 6 of the blood vessel system 5 at. The nodes 7 are in the figures - analogous to the sections 6 - partially supplemented with a lowercase letter, so as nodes 7a . 7b etc. referred to. Again, the respective supplement by the lowercase letters for all figures is uniform and is only illustrative.

To determine the sections 6 Various methods are known to those skilled in the art. These approaches are also applicable in the context of the present invention. For example, the calculator 1 as part of the subdivision of the blood vessel system 5 in the sections 6 in the volume image 4 the central lines 8th the sections 6 determine. The central lines 8th are in 3 dashed lines. A possible procedure for determining the central lines 8th is in the DE 10 2009 006 414 B3 described in detail.

In a step S3, the computer determines 1 for each section 6 one on the respective section 6 related section segmentation nine , The computer 1 determines the segment segmentations nine in particular using the volume image 4 ie the voxels of the volumetric image 4 assigned brightness values. 4 shows purely as an example for the sections 6k and 6q the appropriate section segmentation nine , If the calculator 1 in step S3, the center lines 8th the sections 6 determined, the calculator can 1 in the context of step S3 continue the course of the respective center line 8th consider.

In a step S4, the computer orders 1 the determined section segmentations nine the respective section 6 to. The computer 1 noted for each section 6 which section segmentation nine he for the particular section 6 has determined. For a later selection of a specific section 6 is the calculator 1 thus immediately and immediately the appropriate section segmentation nine known. In particular, the corresponding section segmentation nine - without recalculation of section segmentation nine , so without the volume image 4 having to fall back - directly determined.

The overlay of section segmentations nine corresponds to a total segmentation of the blood vessel system 5 , It is possible that the segment segmentations nine overlap - at least partially. So it is possible that a certain volume range of the volume image 4 two (or possibly more) section segmentations nine is assigned. A possible total segmentation is - purely exemplary - in 3 shown with.

Based on the determined sections 6 and the section segmentations nine - the latter, as already mentioned, the sections 6 are assigned - takes the calculator 1 in a step S5 further measures. For example, the calculator 1 perform a visualization of the total segmentation in step S5 and then carry out further evaluations based thereon.

As part of the further evaluation can the computer 1 from a user 10 (please refer 1 ) interactively further nodes 7 ' be specified. Likewise, the user can 10 the calculator 1 interactively specify further sections 6 '. This will be described below in connection with 5 explained in more detail by way of example.

5 shows - purely by way of example - a section of the blood vessel system 5 and in this excerpt from the calculator 1 determined sections 6 (more precisely, their central lines 8th ) and these sections 6 limiting nodes 7 , In the in 5 shown section run two vessels of the blood vessel system 5 that are in one area 11 touch. In such cases it can happen that the calculator 1 in the context of step S2 does not recognize that it is in the vessels according to the in 5 shown section to two mutually different and thus separate vessels. The computer 1 may in such cases rather - albeit erroneously - that the sections 6c and 6d at the junction 7e in the section 6e pass over and the section 6e at the junction 7f in the sections 6f and 6g divides.

To such errors of the computer 1 the user can correct 10 the calculator 1 - in addition to the computer 1 Nodes determined in step S3 7 - interactively the other nodes 7 ' pretend. The other nodes 7 ' divide the sections 6c . 6d . 6f and 6g in two new sections each. Furthermore, the user can 10 the calculator 1 - in addition to the computer 1 determined in step S3 sections 6 - more sections 6 ' pretend. For example, the user 10 two such further sections 6 ' pretend, each of the two other sections 6 ' two each of the other nodes 7 ' connects with each other. If the given further sections 6 ' not directly at junctions 7 . 7 ' ends, sets the calculator 1 at the appropriate places automatically another node 7 ' ,

The corresponding procedure is also reversible. The user 10 So can the other nodes 7 ' and the other sections 6 ' delete again. The deletion of another node 7 ' is of course only permissible if the corresponding further node 7 ' only two sections 6 . 6 ' limited, so no branching of the blood vessel system 5 is more.

Furthermore, it is possible for the user 10 the calculator 1 pretending, individual sections 6 . 6 ' to disable. This input is also interactive and reversible. Disabled sections 6 . 6 ' So they can be activated again. Disabled sections 6 . 6 ' be from the calculator 1 when superimposing the segment segmentations nine not taken into account for the overall segmentation and / or in the context of the further measures. The computer 1 only takes into account the activated sections 6 . 6 ' ,

For example, the calculator 1 the section 6e and those of the nodes 7e and 7f and the other nodes 7 ' disable limited sections, so that - as a result - the blood vessel system 5 is modified as in 6 is shown. In this case, the calculator 5 for the sections 6u . 6v and 6w on the one hand and for the sections 6x . 6y and 6z on the other hand, again the respective section segmentation nine determine.

By the above in connection with the 5 and 6 explained procedure can be solved in particular the so-called Kissing Vessel problem.

It is possible, starting from the constellation of the activated sections 6 . 6 ' according to 6 , the nodes 7 ' to disable and the sections 6u . 6v and 6w on the one hand and the sections 6x . 6y and 6z on the other hand to a common section 6 with uniform segment segmentation nine summarize. This procedure is preferred and will be described again below, but is not mandatory.

In conjunction with the 7 . 8th and nine is subsequently - starting from 3 - explains a possible course of action that will be taken if a section disabled 6 a section 6 is that only one-sided from a node 7 is limited. Such sections 6 that only one side of a node 7 are hereinafter referred to as "sheet".

In case of deactivation of a sheet 6 - For example, according to 3 of the leaf 6s that only from the node 7y is limited - checks the calculator 1 according to 7 in a step S11 automatically, whether the deactivated sheet 6s limiting node 7y after deactivating said sheet 6s still a "real" node 7 is, ie, that he has at least three activated sections 6 limited. If this is the case, no further action will be taken. Only in the visualization and evaluation of the blood vessel system 5 in a step S12, the deactivated sheet 6s no longer considered. 8th shows a corresponding representation in the event that the in 3 with the reference number 6s designated sheet was disabled.

When the node 7 after disabling the sheet 6 however, only two activated sections 6 limited, so in the negative case, disabled the calculator 1 in one step S13 the corresponding node 7 and grasp the two from this node 7 limited active sections 6 to a common section together. For this common section 6 In step S13, the computer determines the corresponding segment segmentation nine New. He arranges them in a step S14 the common section 6 to. nine shows a corresponding representation in the event that the in 3 with the reference number 6l designated sheet was disabled.

With the procedure according to 7 In particular, so-called side wall aneurysms can be removed virtually in a simple manner. Furthermore, in this way, the original (= healthy) blood vessel system 5 be reconstructed in a reliable way.

It is of course also possible for the user 10 a section 6 disabled, on both sides of a node 7 is limited (hereinafter referred to as branch). In this case, different approaches may be useful.

So it may make sense that the calculator 1 - shortened spoken - concerning both adjacent nodes 7 the above in connection with the 7 to nine explains the explained procedure. If the user 10 such a section 6 disabled, the calculator can according to 10 for example, in a step S21 one of the two adjacent nodes 7 select. In a step S22, the computer checks 1 , whether the selected node 7 is still a "real" node, meaning that it has at least three activated sections 6 limited. If this is not the case, the calculator disables 1 in a step S23, the corresponding node 7 , take the two to the now disabled node 7 adjacent still activated sections 6 to a common section together and determined for the common section 6 the appropriate section segmentation nine , In a step S24 the computer orders 1 the newly determined section segmentation nine the corresponding common section 6 to. The steps S22 to S24 thus correspond - with respect to the selected node 7 The steps S11, S13 and S14 of 7 ,

In a completely analogous way, the calculator 1 in corresponding steps S25 to S28 also the other node 7 to treat. Steps S25 to S28 correspond to the disabled section with respect to the other 6 limiting node 7 - Content with the steps S21 to S24.

In a step S29, the content of the step S12 of 7 corresponds, then carried out a further evaluation, in particular a visualization of the resulting blood vessel system 5 , 11 shows - purely by way of example - a corresponding representation in the event that the in 3 with the reference number 6q designated section has been disabled.

If by the user 10 a branch 6 of the blood vessel system 5 is disabled, it is often beneficial, not according to 10 but according to 12 proceed.

According to 12 asks the calculator 1 in a step S31 at the user 10 after, whether - from the deactivated section 6 - all subsequent nodes 7 and sections 6 should be disabled. If this is the case, the calculator performs 1 in a step S32, the corresponding deactivation. Furthermore, the calculator selects 1 in a step S33 the other node 7 of the disabled section 6 So the previous node 7 , In steps S34 to S36, the calculator performs 1 then, based on the selected node 7 , the same procedure, the above in connection with 7 was explained. The steps S34 to S36 thus correspond - with respect to the selected node 7 The steps S11, S13 and S14 of 7 ,

If the calculator 1 not the following nodes 7 and sections 6 should disable, the calculator asks 1 in a step S37 at the user 10 after, if he has any preceding nodes 7 and sections 6 should disable. If this is the case Case is, the calculator goes 1 to step S32 via. Of course, the steps S32 to S36 in this case are executed in the reverse direction as compared with the step S31.

If the calculator 1 not even the preceding nodes 7 and sections 6 should disable, the calculator goes 1 to a step S38. In step S38, the computer performs 1 the procedure, the above in connection with 10 was explained.

In a step S39 takes place - analogous to the steps S12 and S29 of 7 and 10 - A visualization and further evaluation of the resulting blood vessel system 5 ,

13 shows - purely by way of example - a possible corresponding modification of 3 in the event that the branch 6i has been disabled and all subsequent nodes 7 and sections 6 should be disabled.

As already mentioned, the calculator can 1 as part of the subdivision of the blood vessel system 5 in sections 6 in the volume image 4 the central lines 8th the sections 6 and during the subsequent determination of segment segmentation nine the course of the respective center line 8th consider. This will be described below by means of a possible example in connection with the 14 and 15 explained in more detail.

According to 14 the calculator determines 1 in a step S41 first the central lines 8th the sections 6 , Possible implementations of step S41 are known to those skilled in the art.

In a step S42, the computer sets 1 along the central lines 8th reference points 12 (please refer 15 ). For example, the calculator 1 along the central line 8th of a particular section 6 a fixed number of nodes 12 put or the support points 12 put in a fixed grid or the interpolation points 12 set in a grid, although the pitch may vary, but not fall below a minimum value and must not exceed a maximum value.

In a step S43, the computer determines 1 for each support point 12 In each case a parameterization of a parameterizable volume object in accordance with predefined optimization conditions 13 (please refer 15 ). For example, the calculator 1 for each parameterizable volume object 13 its location (defined by the location of the corresponding support point 12 ), determine its orientation and its dimensions. The corresponding procedure is known to experts, see the already mentioned DE 10 2009 006 414 B3 , The correspondingly parameterized volume objects 13 arranges the calculator 1 in step S43 the corresponding nodes 12 to.

In a step S44, the computer determines 1 - related to the respective section 6 of the blood vessel system 5 - the superposition of the interpolation points 12 Assigned parameterized volume objects 13 ,

It is possible that the mere overlay corresponding to the step S44 already with the determination of the corresponding section segmentation nine is identical. Alternatively, an additional step S45 may be present in which a further interpolation of the parameterized volume objects 13 of the corresponding section 6 he follows. For example, a smoothing can be done. In this case, the corresponding segment segmentation results nine by the interpolation of step S45.

The parameterizable volume objects 13 can be designed as needed, for example as a cuboid or sphere. Preferably, the parameterizable volume objects 13 as shown in 15 and in accordance with the procedure of DE 10 2009 006 414 B3 around ellipsoids.

• – Nachfolgende Abschnitte 6 sollten kleinere Querschnitte aufweisen als vorausgehende Abschnitte 6.
• – Blätter 6 sollten einen maximal zulässigen Querschnitt nicht übersteigen.
• – Innerhalb eines (unverzweigten) Astes 6 sollte der Querschnitt im Wesentlichen – d. h. innerhalb eines vorbestimmten Schwankungsbereichs – konstant bleiben.

The - if necessary after making the appropriate manipulations, the above in connection with the 5 to 15 were explained - resulting blood vessel system 5 can be evaluated in various ways. For example, the calculator 1 according to 16 - Preferably automatically - in a step S61 geometric dimensions and dimensional ratios of the blood vessel system 5 determine. For example, the calculator 1 in the context of step S51, the length and / or the average or maximum diameter or cross sections of the sections 6 determine and list in tabular form. A more extensive automated evaluation is possible. This is how the calculator works 1 For example, in a step S52 check whether the determined geometric dimensions and dimensional ratios violate predetermined conditions. Examples of such conditions are:

• - Subsequent sections 6 should have smaller cross sections than previous sections 6 ,
• - Leaves 6 should not exceed a maximum allowable cross section.
• - Within a (unbranched) branch 6 the cross-section should remain substantially constant, ie within a predetermined fluctuation range.

If one of these conditions - or even several - are violated, the calculator can 1 in a step S53 a corresponding message the user 10 spend the user 10 So inform yourself about the violation of the condition or conditions. For example, the calculator 1 - see in 17 the corresponding hatched area - the location of the blood vessel system 5 in which the predefined condition is violated, in a representation of the blood vessel system 5 mark automatically.

Furthermore, the calculator 1 in a step S56, a start command of the user 10 wait. If the start command is the calculator 1 is specified, the calculator performs 1 in a step S57, a blood flow simulation and outputs the result in a step S58 to the user 10 out.

The present invention has many advantages. In particular, for the user 10 a flexible and intuitive manipulation of the (virtual) blood vessel system 5 possible. The determination of the sections 6 and the segment segmentations nine provides optimal results, since always with the data (voxels and their voxel data) of the volume image 4 is working.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009006414 B3 [0048, 0078, 0081]

Cited non-patent literature

• "Hemodynamics in a Cerebral Artery before and After the Formation of Aneurysm" by A. Mantha et al., American Journal of Neuroradiology (2006), Number 27, pages 1113 to 1118 [0007]
• A. Mohamed et al., Medical Imaging 2010: Visualization, Image Guided Procedures and Modeling, Proc. of SPIE, Vol. 7625, 2010, pages 1 to 9 [0008]
• MD Ford et al., British Journal of Radiology, January 1, 2009, 82 (Special Issue 1), pages 55 to 61 [0009]

Claims (17)

Evaluation method for a blood vessel system ( 5 ) of a patient by a computer ( 1 ), - the computer ( 1 ) a three-dimensional spatially resolved volume image ( 4 ) of the blood vessel system ( 5 ), the computer ( 1 ) the blood vessel system ( 5 ) into sections ( 6 ), whereby the from the computer ( 1 ) sections ( 6 ) are branch-free in each case and on one side or on both sides of a node ( 7 ), - the nodes ( 7 ) on at least three of the computers ( 1 ) sections ( 6 ), - whereby the computer ( 1 ) for the sections ( 6 ) one on each section ( 6 ) related segmentation ( nine ) of the blood vessel system ( 5 ) in the three-dimensional spatially resolved volume image ( 4 ), the superposition of the segment segmentations ( nine ) of total segmentation of the blood vessel system ( 5 ), - the computer ( 1 ) the determined segment segmentations ( nine ) the relevant section ( 6 ), so that when selecting a particular section ( 6 ) the associated section segmentation ( nine ) is determined directly, and - wherein the computer ( 1 ), based on the identified sections ( 6 ) and the sections ( 6 ) associated segment segmentations ( nine ), takes further action. Evaluation method according to claim 1, characterized in that the computer ( 1 ) by a user ( 10 ) interactively and reversibly in addition to those from the computer ( 1 ) in the context of the subdivision of the blood vessel system ( 5 ) into sections ( 6 ) identified nodes ( 7 ) a section ( 6 ) into two new sections ( 6 ) dividing further nodes ( 7 ' ) can be specified. Evaluation method according to claim 1 or 2, characterized in that the computer ( 1 ) by a user ( 10 ) interactively and reversibly in addition to those from the computer ( 1 ) in the context of the subdivision of the blood vessel system ( 5 ) into sections ( 6 ) sections ( 6 ) further sections (6 ') can be specified. Evaluation method according to claim 1, 2 or 3, characterized in that the computer ( 1 ) by a user ( 10 ) for each of the sections ( 6 . 6 ' ), whether the respective section ( 6 . 6 ' ) is activated or deactivated, and that the computer ( 1 ) in the superimposition of the segment segmentations ( nine ) for the overall segmentation and / or in the context of the further actions only the activated sections ( 6 . 6 ' ) considered. Evaluation method according to claim 4, characterized in that in the case that the user ( 10 ) a section ( 6 ), which is only one-sided from one node ( 7 ), the computer ( 1 ) automatically checks whether the deactivated section ( 6 ) limiting node ( 7 ) at least three activated sections ( 6 ) and, if so, the corresponding node ( 7 ), the two still from the corresponding node ( 7 ) limited activated sections ( 6 ) to a common section ( 6 ) and for the common section ( 6 ) the section segmentation ( nine ) and the common section ( 6 ). Evaluation method according to claim 4 or 5, characterized in that in the case that the user ( 10 ) a section ( 6 ), which is on both sides of a node ( 7 ), the computer ( 1 ) for both the deactivated section ( 6 ) limiting nodes ( 7 ) automatically checks whether at least three activated sections ( 6 ) and, if appropriate, the respective node ( 7 ), which are still dependent on the respective node ( 7 ) limited activated sections ( 6 ) to a respective common section ( 6 ) and for each common section ( 6 ) the respective segment segmentation ( nine ) and the relevant common section ( 6 ). Evaluation method according to claim 4 or 5, characterized in that in the case that the user ( 10 ) a section ( 6 ), which is on both sides of a node ( 7 ), the computer ( 1 ) - the user ( 10 ) asks whether starting from the deactivated section ( 6 ) all subsequent or previous nodes ( 7 ) and sections ( 6 ) should be deactivated, - if appropriate, the corresponding nodes ( 7 ) and sections ( 6 ), automatically checks whether the other one has disabled the section ( 6 ) limiting node ( 7 ) at least three activated sections ( 6 ) and, if not, the other node ( 7 ), the two still from the other node ( 7 ) limited activated sections ( 6 ) to a common section ( 6 ) and for the common section ( 6 ) the section segmentation ( nine ) and the common section ( 6 ) and, if not, for both the deactivated section ( 6 ) limiting nodes ( 7 ) automatically checks whether at least three activated sections ( 6 ) and, if appropriate, the respective node ( 7 ), which are still dependent on the respective node ( 7 ) limited activated sections ( 6 ) to a respective common section ( 6 ) and for the respective common section ( 6 ) the respective segment segmentation ( nine ) and the relevant common section ( 6 ). Evaluation method according to one of the above claims, characterized in that the computer ( 1 ) in the context of the subdivision of the blood vessel system ( 5 ) into sections ( 6 ) in the volume image ( 4 ) the central lines ( 8th ) of the sections ( 6 ) and in the context of determining segment segmentation ( nine ) the course of the respective center line ( 8th ) considered. Evaluation method according to claim 8, characterized in that the computer ( 1 ) in the context of the determination of segmental segmentation ( nine ) - along the central lines ( 8th ) Support points ( 12 ), - for the reference points ( 12 ) according to predefined optimization conditions in each case a parameterization of a parameterizable volume object ( 13 ), - the volume object parameterized with the parameterization determined in each case ( 13 ) of the respective support point ( 12 ) and - the respective segment segmentation ( nine ) based on the superposition of the parameterized volume objects ( 13 ) in the respective section ( 6 ) ( 12 ). Evaluation method according to claim 8 or 9, characterized in that the parameterizations location, orientation and dimensions of the parameterizable volume object ( 13 ) in the volume image ( 4 ). Evaluation method according to claim 8, 9 or 10, characterized in that the parameterizable volume objects ( 13 ) Ellipsoids are. Evaluation method according to one of the above claims, characterized in that the further measures comprise a blood flow simulation. Evaluation method according to one of the above claims, characterized in that the further measures include a determination of geometric dimensions and / or dimensional ratios of the blood vessel system ( 5 ). Evaluation method according to claim 13, characterized in that in the case that the determined geometric dimensions and / or dimensional ratios of the blood vessel system ( 5 ) violate a predefined condition, the further measures an automatic information of a user ( 10 ) about this. Evaluation method according to claim 14, characterized in that the location of the blood vessel system ( 5 ), where the predefined condition is violated, by the computer ( 1 ) in a representation of the blood vessel system ( 5 ) is marked automatically. Computer program, the machine code ( 3 ) generated by a computer ( 1 ) is immediately executable and its execution by the computer ( 1 ) causes the computer ( 1 ) performs an evaluation method with all the steps of an evaluation method according to one of the above claims in operation. Computer, characterized in that the computer is programmed so that it executes an evaluation method with all steps of an evaluation method according to one of claims 1 to 15 during operation.

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