PROVISION OF A COMPARISON DATASET

Abstract

A method for providing a comparison dataset is disclosed. The method includes providing a time-resolved first dataset that maps a first contrast medium flow in a region of interest of an examination object in a first period of time; providing a time-resolved second dataset that maps a second contrast medium flow in the region of interest in a second period of time after the first period of time; spatially registering the first and second datasets; identifying a mapping of at least one vessel section of the region of interest in the first and second datasets; temporally registering the first and second datasets; identifying a difference between the first and second contrast medium flows by a comparison of the registered first and second datasets; and providing the comparison dataset based on the registered first and second datasets, wherein the comparison dataset has at least one parameter characterizing the difference.

Claims

1. A method for providing a comparison dataset, the method comprising: providing a time-resolved first dataset, which maps a first contrast medium flow in a region of interest of an examination object in a first period of time; providing a time-resolved second dataset, which maps a second contrast medium flow in the region of interest of the examination object in a second period of time after the first period of time; spatially registering the first dataset and the second dataset; identifying a mapping of at least one vessel section of the region of interest in the first dataset and the second dataset with aid of a direction of a mapped flooding of the first contrast medium flow and/or of the second contrast medium flow; temporally registering the first dataset and the second dataset to minimize a temporal difference of the mapped flooding of the first contrast medium flow and the second contrast medium flow in the at least one vessel section; identifying a difference between the first contrast medium flow and the second contrast medium flow by a comparison of the registered first and second datasets; and providing the comparison dataset based on the registered first and second datasets, wherein the comparison dataset has at least one parameter characterizing the difference.

2. The method of claim 1, wherein the at least one vessel section is an afferent vessel section.

3. The method of claim 1, wherein the providing of the first dataset comprises receiving previously acquired first image data, wherein the first dataset is reconstructed from the first image data, wherein the providing of the second dataset comprises receiving previously acquired second image data, and wherein the second dataset is reconstructed from the second image data.

4. The method of claim 3, wherein the first image data has a plurality of first projection images of the examination object from at least partly different first projection directions, wherein the first dataset is reconstructed from the plurality of first projection images, wherein the second image data has a plurality of second projection images of the examination object from at least partly different second projection directions, and wherein the second dataset is reconstructed from the plurality of second projection images.

5. The method of claim 4, wherein the first image data and/or the second image data has at least one mask image, wherein the first image data has a plurality of first fill images, wherein the reconstruction of the first dataset comprises a subtraction of the at least one mask image from the plurality of first fill images, wherein the second image data has a plurality of second fill images, and wherein the reconstruction of the second dataset comprises a subtraction of the at least one mask image from the plurality of second fill images.

6. The method of claim 3, wherein the first image data and/or the second image data has at least one mask image, wherein the first image data has a plurality of first fill images, wherein the reconstruction of the first dataset comprises a subtraction of the at least one mask image from the plurality of first fill images, wherein the second image data has a plurality of second fill images, and wherein the reconstruction of the second dataset comprises a subtraction of the at least one mask image from the plurality of second fill images.

7. The method of claim 3, wherein the registered first and second datasets each have a plurality of image points with a time intensity curve, wherein the identifying of the difference between the first contrast medium flow and the second contrast medium flow comprises a comparison of the time intensity curves of image points of the plurality of image points of the registered first and second datasets corresponding spatially to one another, and wherein the at least one parameter characterizing the difference describing a filling delay and/or a flow rate relationship is determined with aid of the comparison of the time intensity curves of the image points of the registered first and second datasets corresponding spatially to one another.

8. The method of claim 7, wherein the comparison of the time intensity curves comprises a comparison of a gradient, a variance, an average intensity value, a maximum intensity value, an accumulated intensity value, or a combination thereof of the image points of the registered first and second datasets corresponding spatially to one another.

9. The method of claim 7, wherein at least one first image point and at least one second image point in the registered first and second datasets is determined in each case, wherein the at least one first image point and the at least one second image point map two different spatial positions in the at least one vessel section, wherein a spatial position mapped by the at least one second image point is arranged downstream in relation to a spatial position mapped by the at least one first image point, wherein a bolus arrival time is determined in each case as a time of the mapped flooding of the first contrast medium flow and the second contrast medium flow at the spatial position mapped by the at least one second image point, and wherein the difference is identified based on the bolus arrival times of the at least one second image point and the comparison of the time intensity curves of the at least one first image point of the registered first and second datasets.

10. The method of claim 7, wherein at least one first image point and at least one second image point is defined in each case in the registered first and second datasets, wherein the at least one first image point and the at least one second image point map two different spatial positions in the at least one vessel section, wherein the identification of the difference between the first contrast medium flow and the second contrast medium flow comprises: determining a first relationship between the time intensity curves of the at least one first image point in the registered first and second datasets; determining a second relationship between the time intensity curves of the at least one second image point in the registered first and second datasets; and determining a third relationship between the first relationship and the second relationship, wherein the difference is identified with aid of the third relationship.

11. The method of claim 1, wherein the registered first and second datasets each have a plurality of image points with a time intensity curve, wherein the identifying of the difference between the first contrast medium flow and the second contrast medium flow comprises a comparison of the time intensity curves of image points of the plurality of image points of the registered first and second datasets corresponding spatially to one another, and wherein the at least one parameter characterizing the difference describing a filling delay and/or a flow rate relationship is determined with aid of the comparison of the time intensity curves of the image points of the registered first and second datasets corresponding spatially to one another.

12. The method of claim 11, wherein the comparison of the time intensity curves comprises a comparison of a gradient, a variance, an average intensity value, a maximum intensity value, an accumulated intensity value, or a combination thereof of the image points of the registered first and second datasets corresponding spatially to one another.

13. The method of claim 11, wherein at least one first image point and at least one second image point in the registered first and second datasets is determined in each case, wherein the at least one first image point and the at least one second image point map two different spatial positions in the at least one vessel section, wherein a spatial position mapped by the at least one second image point is arranged downstream in relation to a spatial position mapped by the at least one first image point, wherein a bolus arrival time is determined in each case as a time of the mapped flooding of the first contrast medium flow and the second contrast medium flow at the spatial position mapped by the at least one second image point, and wherein the difference is identified based on the bolus arrival times of the at least one second image point and the comparison of the time intensity curves of the at least one first image point of the registered first and second datasets.

14. The method of claim 11, wherein at least one first image point and at least one second image point is defined in each case in the registered first and second datasets, wherein the at least one first image point and the at least one second image point map two different spatial positions in the at least one vessel section, wherein the identification of the difference between the first contrast medium flow and the second contrast medium flow comprises: determining a first relationship between the time intensity curves of the at least one first image point in the registered first and second datasets; determining a second relationship between the time intensity curves of the at least one second image point in the registered first and second datasets; and determining a third relationship between the first relationship and the second relationship, wherein the difference is identified with aid of the third relationship.

15. The method of claim 14, wherein the region of interest has a vessel malformation, a stenosis, an aneurysm, or a combination thereof, wherein the at least one vessel section is afferent and/or efferent to the vessel malformation, the stenosis, the aneurysm, or a combination thereof, wherein the at least one first image point maps a spatial position within or proximal and the at least one second image point a spatial position distal in relation to the vessel malformation, the stenosis, the aneurysm, or a combination thereof in each case, or wherein the at least one first image point in each case maps a spatial position proximal and the at least one second image point a spatial position within in relation to the vessel malformation the stenosis and/or the aneurysm.

16. The method of claim 13, wherein the region of interest has a vessel malformation, a stenosis, an aneurysm, or a combination thereof, wherein the at least one vessel section is afferent and/or efferent to the vessel malformation, the stenosis, the aneurysm, or a combination thereof, wherein the at least one first image point maps a spatial position within or proximal and the at least one second image point a spatial position distal in relation to the vessel malformation, the stenosis, the aneurysm, or a combination thereof in each case, or wherein the at least one first image point in each case maps a spatial position proximal and the at least one second image point a spatial position within in relation to the vessel malformation the stenosis and/or the aneurysm.

17. The method of claim 11, wherein an injection parameter of the first contrast medium flow and of the second contrast medium flow is received in each case, wherein the time intensity curves are normalized based on the injection parameters, wherein the identifying of the difference between the first contrast medium flow and the second contrast medium flow comprises a comparison of the normalized time intensity curves of image points of the registered first and second datasets corresponding spatially to one another.

18. A provision unit configured to: provide a time-resolved first dataset, which maps a first contrast medium flow in a region of interest of an examination object in a first period of time; provide a time-resolved second dataset, which maps a second contrast medium flow in the region of interest of the examination object in a second period of time after the first period of time; spatially register the first dataset and the second dataset; identify a mapping of at least one vessel section of the region of interest in the first dataset and the second dataset with aid of a direction of a mapped flooding of the first contrast medium flow and/or of the second contrast medium flow; temporally register the first dataset and the second dataset to minimize a temporal difference of the mapped flooding of the first contrast medium flow and the second contrast medium flow in the at least one vessel section; identify a difference between the first contrast medium flow and the second contrast medium flow by a comparison of the registered first and second datasets; and provide a comparison dataset based on the registered first and second datasets, wherein the comparison dataset has at least one parameter characterizing the difference.

19. A medical imaging device comprising: a provision unit configured to: provide a time-resolved first dataset, which maps a first contrast medium flow in a region of interest of an examination object in a first period of time; provide a time-resolved second dataset, which maps a second contrast medium flow in the region of interest of the examination object in a second period of time after the first period of time; spatially register the first dataset and the second dataset; identify a mapping of at least one vessel section of the region of interest in the first dataset and the second dataset with aid of a direction of a mapped flooding of the first contrast medium flow and/or of the second contrast medium flow; temporally register the first dataset and the second dataset to minimize a temporal difference of the mapped flooding of the first contrast medium flow and the second contrast medium flow in the at least one vessel section; identify a difference between the first contrast medium flow and the second contrast medium flow by a comparison of the registered first and second datasets; and provide a comparison dataset based on the registered first and second datasets, wherein the comparison dataset has at least one parameter characterizing the difference wherein the medical imaging device is configured to receive and/or provide the first dataset and the second dataset.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Exemplary embodiments of the disclosure are shown in the drawings and are described below in further detail. The same reference characters are used in different figures for the same features. In the figures:

[0078] FIG. 1 depicts a schematic diagram of an advantageous form of embodiment of a proposed method for provision of a comparison dataset.

[0079] FIG. 2 depicts a schematic diagram of time intensity curves of the registered first and second dataset spatially corresponding to one another, according to an embodiment.

[0080] FIGS. 3 to 5 depict schematic diagrams of further advantageous forms of embodiments of the proposed method for provision of a comparison dataset.

[0081] FIG. 6 depicts a schematic diagram of a region of interest having an aneurysm and at least one vessel section, according to an embodiment.

[0082] FIGS. 7 and 8 depict schematic diagrams of time intensity curves of different spatial positions along a vessel section, according to embodiments.

[0083] FIG. 9 depicts a schematic diagram of a proposed provision unit, according to an embodiment.

[0084] FIG. 10 depicts a schematic diagram of a proposed medical imaging device, according to an embodiment.

DETAILED DESCRIPTION

[0085] Shown schematically in FIG. 1 is an advantageous form of embodiment of a proposed method for provision PROV-CD of a comparison dataset CD. In this case, a time-resolved first dataset D1 may be provided PROV-D1, which maps a first contrast medium flow in a region of interest of an examination object in a first period of time. A time-resolved second dataset D2 may further be provided PROV-D2, which maps a second contrast medium flow in the region of interest of the examination object in a second period of time after the first period of time. Moreover, the first dataset D1 and the second dataset D2 may be registered spatially to one another SREG-D1-D2. Furthermore a mapping of at least one, in particular afferent, vessel section of the region of interest in the first D1 and the second dataset D2 with the aid of a direction of a mapped flooding of the first and/or of the second contrast medium flow may be identified ID-V. The first D1 and the second dataset D2, for minimizing a temporal difference of the mapped flooding of the first and second contrast medium flow, may be temporally registered TREG-D1-D2 in the at least one vessel section. Moreover, a difference ID-DIFF between the first and the second contrast medium flow may be identified by a comparison of the registered first D1.REG and second dataset D2.REG. The comparison dataset CD may further be provided PROV-CD based on the registered first D1.REG and second dataset D2.REG, wherein the comparison dataset CD has at least one parameter P.DIFF characterizing the difference.

[0086] FIG. 2 shows a schematic diagram of time intensity curves of the registered first dataset D1.REG and second dataset D2.REG corresponding spatially to one another. Advantageously, the registered first dataset D1.REG and the registered second dataset D2.REG may have a number of image points each with a time intensity curve I.sub.D1.REG and I.sub.D2.REG. In this case, the identification of the difference ID-DIFF between the first and the second contrast medium flow may include a comparison of the time intensity curves I.sub.D1.REG and I.sub.D2.REG, in particular of a gradient, a variance, an average intensity value, a maximum intensity value, and/or an accumulated intensity value of the time intensity curves I.sub.D1.REG and I.sub.D2.REG, of image points of the registered first dataset D1.REG and of the registered second dataset D2.REG corresponding spatially to one another. Moreover, the at least one parameter P.DIFF characterizing the difference describing a filling delay and/or a flow rate relationship may be determined with the aid of the comparison of the image points of the time intensity curves I.sub.D1.REG and I.sub.D2.REG of the registered first dataset D1.REG and of the registered second dataset D2.REG corresponding spatially to one another.

[0087] Through the spatial and temporal registration of the first D1.REG and second dataset D2.REG the time intensity curves I.sub.D1.REG and I.sub.D2.REG corresponding spatially to one another may be registered temporally in relation to a respective mapped flooding of the first and second contrast medium flow, in particular a bolus arrival time t.sub.BAT. Advantageously, the time intensity curves I.sub.D1.REG and I.sub.D2.REG corresponding spatially to one another may be compared in order to determine the parameter P.DIFF characterizing the difference. For this, for example, a temporal difference between the bolus arrival time t.sub.BAT and a time until a predetermined intensity threshold value of the time intensity curves I.sub.D1.REG and I.sub.D2.REG is reached or exceeded may be determined. An intensity value of 33% of the maximum intensity value, in particular of a filling intensity value I.sub.Fill, may be predetermined for the intensity threshold value, for example. In this case, the temporal difference between the bolus arrival time t.sub.BAT and the respective time t.sub.33%,D1.REG, t.sub.33%,D2.REG until a predetermined intensity threshold value is reached or exceeded, in particular 33% I.sub.Fill, may be determined. As an alternative, a temporal difference between the bolus arrival time t.sub.BAT and a time until a predetermined surface threshold value is reached or exceeded of a surface below the time intensity curve, (e.g., 5% of a surface below the time intensity curve beginning with the bolus arrival time t.sub.BAT), may be determined. By a comparison of the temporal differences (t.sub.33%,D1.REG−t.sub.BAT) and (t.sub.33%,D2.REG−t.sub.BAT), a change in a filling rate of the at least one vessel section between the first and the second period of time may be identified.

[0088] FIG. 3 shows a schematic diagram of a further advantageous form of embodiment of a proposed method for provision PROV-CD of a comparison dataset CD. In this case, the provision PROV-D1 of the first dataset D1 may include a receipt REC-ID1 of previously acquired image data ID1. Moreover, the first dataset D1 may be reconstructed RECO-D1 from the first image data ID1. Furthermore, the provision PROV-D2 of the second dataset D2 may include a receipt REC-ID2 of previously acquired second image data D2. In this case, the second dataset D2 may be reconstructed RECO-D2 from the second image data ID2.

[0089] Advantageously, the first image data ID1 may have a number of first projection images of the examination object from at least partly different first projection directions. In this case, the time-resolved first dataset D1 may be reconstructed RECO-D1 from the first projection images. The second image data ID2 may further have a number of second projection images of the examination object from at least partly different second projection directions. In this case, the time-resolved second dataset D2 may be reconstructed RECO-D2 from the second projection images.

[0090] Shown schematically in FIG. 4 is a further advantageous form of embodiment of a proposed method for provision PROV-CD of a comparison dataset CD. In this case, the first ID1 and/or the second image data ID2 may have at least one mask image, in particular one mask image MI1 and MI2 in each case. The first image data ID1 may further have a number of first fill images FI1. In this case, the reconstruction RECO-D1 of the first dataset D1 may include a subtraction DIFF-MI1-FI1 of the at least one mask image MI1 from the number of first fill images FI1. The second image data ID2 may further have a number of second fill images FI2. In this case, the reconstruction RECO-ID2 of the second dataset D2 may include a subtraction DIFF-MI2-FI2 of the at least one mask image MI2 from the number of second fill images FI2.

[0091] FIG. 5 shows a schematic diagram of a further advantageous form of embodiment of a proposed method for provision PROV-CD of a comparison dataset CD. In this case an injection parameter IP of the first and of the second contrast medium flow may be received REC-IP. The time intensity curves may further be normalized based on the injection parameters IP. Moreover, the identification of the difference ID-DIFF between the first and second contrast medium flow may include a comparison of the normalized time intensity curves of the image points of the registered first dataset D1.REG and of the registered second dataset D2.REG corresponding spatially to one another.

[0092] Shown schematically in FIG. 6 is an example of a region of interest having an aneurysm AV and the at least one vessel section V. The at least one vessel section V may be afferent, in particular supplying, and/or efferent, in particular discharging, to/from the aneurysm AV. In this case, a direction of flow FD, in particular a direction of the flooding of the first and second contrast medium flow, in the at least one vessel section V is illustrated in FIG. 6 by an arrow.

[0093] Advantageously, in each case, at least one first and at least one second image point may be defined in the registered first D1.REG and the registered second dataset D2.REG, with the image points mapping two different spatial positions in the at least one vessel section V. In this case, the at least one first image point may map a spatial position within P2 or proximal P1 and the at least one second image point a spatial position distal P3 in relation to the aneurysm AV in each case. As an alternative, the at least one first image point may map a spatial position proximal P1 and the at least one second image point a spatial position within P2 in relation to the aneurysm AV in each case. The three different spatial positions P1, P2, and P3 will also be referred to below as first spatial position P1, second spatial position P2, and third spatial position P3.

[0094] Advantageously, the identification of the difference ID-DIFF between the first and the second contrast medium flow may include a determination of a first relationship between the time intensity curves, in particular a gradient, a variance, an average intensity value, a maximum intensity value, and/or an accumulated intensity value of the time intensity curves, of the at least one first image point in the registered first D1.REG and second dataset D2.REG. Moreover, the identification of the difference ID-DIFF may include a determination of a second relationship between the time intensity curves, in particular a gradient, a variance, an average intensity value, a maximum intensity value, and/or an accumulated intensity value of the time intensity curves, of the at least one second image point in the registered first D1.REG and second dataset D2.REG. Furthermore, a third relationship between the first and the second relationship may be determined, wherein the difference is identified ID-DIFF with the aid of the third relationship.

[0095] Mapped schematically in FIG. 7 are the time intensity curves I.sub.D1.REG,P1, I.sub.D1.REG,P2 and I.sub.D1.REG,P3 of the image points of the registered first dataset D1.REG, with the image points mapping the different spatial positions P1, P2, and P3 in the at least one vessel section V shown in FIG. 6. The comparisons and/or analyses described below of the time intensity curves I.sub.D1.REG.P1, I.sub.D1.REG,P2 and I.sub.D1.REG,P3 of the image points of the registered first dataset D1.REG are similarly able to be transferred to the time intensity curves I.sub.D2.REG,P1, I.sub.D2.REG,P2 and I.sub.D1.REG,P3 of the image points of the registered second dataset D2.REG (not shown here).

[0096] Advantageously, the time intensity curves I.sub.D1.REG.P1, I.sub.D1.REG,P2 and I.sub.D1.REG,P3 may be registered temporally with regard to the flooding of the first contrast medium flow, in particular the bolus arrival time t.sub.BAT in each case.

[0097] For the determination of the first and of the second relationship, the temporal difference between the bolus arrival time t.sub.BAT and a time until a predetermined intensity threshold value of the respective time intensity curves is reached or exceeded may be determined. An intensity value of 33% of the maximum intensity value, in particular of the filling intensity value I.sub.Fill, may be predetermined for the intensity threshold value for example.

[0098] For example, the at least one first image point may map the spatial position proximal P1 and the at least one second image point the spatial position distal P3 in relation to the aneurysm AV in each case. In this case, the first relationship may be determined as the temporal difference between the bolus arrival time t.sub.BAT and the respective time t.sub.33%,D1.REG,P1, t.sub.33%,D2.REG.P1 until the predetermined intensity threshold is reach or exceeded, in particular 33% I.sub.Fill, of the time intensity curves I.sub.D1.REG,P1 and I.sub.D2.REG,P1 of the at least one first image point:

R.sub.P1=(t.sub.33%,D2.REG,P1−t.sub.33%,D1.REG,P1)  (1).

[0099] The second relationship may further be determined as the temporal difference between the bolus arrival time t.sub.BAT and the respective time t.sub.33%,D1.REG,P3, t.sub.33%,D2.REG,P3 until the predetermined intensity threshold is reach or exceeded, in particular 33% Inn, of the time intensity curves I.sub.D1.REG,P3 and I.sub.D2.REG,P3 of the at least one second image point:

R.sub.P3=(t.sub.33%,D2.REG,P3−t.sub.33%,D1.REG,P3)  (2).

[0100] Furthermore, the third relationship DR.sub.P3,P1 may be determined as the difference between the second RP3 and the first relationship RP1:

DR.sub.P3,P1=R.sub.P3−R.sub.P1=(t.sub.33%,D2.REG,P3−t.sub.33%,D1.REG,P3)−(t.sub.33%,D2.REG,P1−t.sub.33%,D1.REG,P1)  (3)

[0101] In this case, the third relationship DR.sub.P3,P1 may describe the changed filling delay between the first and the second period of time of the third spatial position P3 in relation to the first spatial position P1. The at least one parameter P.DIFF characterizing the difference may include the third relationship DR.sub.P3,P1.

[0102] As an alternative, the at least one first image point may map the spatial position within P2 and the at least one second image point the spatial position distal P3, in relation to the aneurysm AV in each case. In this case, the computation of the first relationship RP.sub.P2 may be configured accordingly to the second spatial position P2 mapped by the at least one first image point. The third relationship DR.sub.P3,P2 may further describe the filling delay changed between the first and the second period of time at the third spatial position P3 in relation to the second spatial position P2:

DR.sub.P3,P2=(R.sub.P3−R.sub.P2)=(t.sub.33%,D2.REG,P3−t.sub.33%,D1.REG,P3)−(t.sub.33%,D2.REG,P2−t.sub.33%,D1.REG,P2)  (4).

[0103] FIG. 8 shows a schematic diagram of the time intensity curves I.sub.D1.REG,P1, I.sub.D1.REG,P2 and I.sub.D1.REG,P3 of the image points of the registered first dataset D1.REG, with the image points mapping the different spatial positions P1, P2, and P3 in the at least one vessel section V shown in FIG. 6. In this case the time intensity curves I.sub.D1.REG,P1, I.sub.D1.REG,P2 and I.sub.D1.REG,P3 are only shown with the same gradient for purposes of illustration. The time intensity curves I.sub.D1.REG,P1, I.sub.D1.REG,P2 and I.sub.D1.REG,P3 are further not registered temporally with one another in this form of embodiment.

[0104] To determine relative flow changes between a first spatial position of interest IP1, in particular the first P1 and/or the second spatial position P2, and a first reference position RP1 arranged downstream in the at least one vessel section V in relation to the first position of interest IP1, in particular the third spatial position P3, Fick's principle in particular a conservation of mass, may be applied:

[00001]$\begin{array}{cc}{Q}_{\mathrm{IP}1}\left(T\right)=V_{\mathrm{IP}1}\underset{0}{\overset{T}{\int }}\left[C_{\mathrm{IP}1}\left(t\right)-C_{RP1}\left(t\right)\right]\mathrm{dt}& \left(5\right)\end{array}$$\begin{array}{cc}{\left[\frac{d{Q}_{\mathrm{IP}1}\left(t\right)}{dt}\right]}_{t=T}=V_{\mathrm{IP}1}.Math.{\left[C_{\mathrm{IP}1}\left(t\right)-C_{RP1}\left(t\right)\right]}_{t=T}& \left(6\right)\end{array}$

[0105] In this case, Q.sub.IP1 may refer to an accumulated mass of the contrast medium, V.sub.IP1 to a volume flow, C.sub.IP1 and C.sub.RP1 to a contrast medium concentration at the respective spatial position IP1 or RP1.

[0106] A speed of the accumulation of the contrast medium may reach a local maximum when a difference between the contrast medium concentration at the first spatial position of interest IP1 and the first spatial reference position RP1 is at a maximum. This local maximum may be reached at a time of the flooding of the first and/or second contrast medium flow at the downstream first reference position RP1, in particular a bolus arrival time t.sub.BAT.RP1 at the first spatial reference position RP1.

[0107] Thus the result of equation (6) is:

[00002]$\begin{array}{cc}{\left[\frac{d{Q}_{\mathrm{IP}1}\left(t\right)}{dt}\right]}_{t=t_{\mathrm{BAT},\mathrm{RP}1}}=V_{\mathrm{IP}1}.Math.C_{\mathrm{IP}1}\left(t_{BAT,RP1}\right),& \left(7\right)\end{array}$$\begin{array}{cc}\frac{{\left[\frac{{\mathrm{dQ}}_{\mathrm{IP}1}\left(t\right)}{\mathrm{dt}}\right]}_{t_{BAT,RP1}}}{C_{\mathrm{IP}1}\left(t_{BAT,RP1}\right)}=V_{\mathrm{IP}1}.& \left(8\right)\end{array}$

[0108] Because C.sub.IP1∝I.sub.IP1, it follows that:

C.sub.IP1(t.sub.BAT,RP1)=k.Math.I.sub.IP1(t.sub.BAT,RP1)  (9).

[0109] From equation (8) and (9) it follows that:

[00003]$\begin{array}{cc}\frac{{\left[\frac{{\mathrm{dQ}}_{\mathrm{IP}1}\left(t\right)}{\mathrm{dt}}\right]}_{t_{\mathrm{BAT},\mathrm{RP}1}}}{I_{\mathrm{IP}1}\left(t_{BAT,RP1}\right)}=V_{\mathrm{rel},\mathrm{IP}1},& \left(10\right)\end{array}$

wherein V.sub.rei,IP1=k.Math.V.sub.IP1.

[0110] Further it follows from equation (7) and (9) that:

[00004]$\begin{array}{cc}{\left[\frac{d{Q}_{\mathrm{IP}1}\left(t\right)}{dt}\right]}_{t_{\mathrm{BAT},\mathrm{RP}1}}\propto {\left[\frac{{\mathrm{dI}}_{\mathrm{IP}1}\left(t\right)}{dt}\right]}_{t_{\mathrm{BAT},\mathrm{RP}1}}.& \left(11\right)\end{array}$

[0111] A relationship between the relative volume flows, which are mapped in the registered first D1.REG and second dataset D2.REG, is produced in accordance with equation (10):

[00005]$\begin{array}{cc}\frac{{\left[\frac{{\mathrm{dQ}}_{D2.\mathrm{REG},\mathrm{IP}1}\left(t\right)}{\mathrm{dt}}\right]}_{t_{\mathrm{BAT},D2.\mathrm{REG},\mathrm{RP}1}}}{{\left[\frac{{\mathrm{dQ}}_{D1.\mathrm{REG},\mathrm{IP}1}\left(t\right)}{\mathrm{dt}}\right]}_{t_{\mathrm{BAT},D1.\mathrm{REG},\mathrm{RP}1}}}.Math.\frac{I_{D1.\mathrm{REG},\mathrm{IP}1}\left(t_{BAT,D1.\mathrm{REG},RP1}\right)}{I_{D2.\mathrm{REG},\mathrm{IP}1}\left(t_{BAT,D2.\mathrm{REG},RP1}\right)}=\frac{V_{D2.\mathrm{REG},\mathrm{IP}1}}{V_{D1.\mathrm{REG},\mathrm{IP}1}}.& \left(12\right)\end{array}$

[0112] In this case,

[00006]$\frac{V_{D2.\mathrm{REG},\mathrm{IP}1}}{V_{D1.\mathrm{REG},\mathrm{IP}1}}$

describes a relationship of the volume flow rates at the first position of interest IP1 in the at least one vessel section V in the first and second period of time.

[0113] Assuming that the injection parameters of the first and second contrast medium flow are constant, and a vascular volume remain the same in the at least one vessel section between the first and second period of time, it may be assumed that:

[00007]$\begin{array}{cc}\frac{I_{D1.\mathrm{REG},\mathrm{IP}1}\left(t_{BAT,D1.\mathrm{REG},RP1}\right)}{I_{D2.\mathrm{REG},\mathrm{IP}1}\left(t_{BAT,D2.\mathrm{REG},RP1}\right)}\approx 1.& \left(13\right)\end{array}$

[0114] From the equations (11) to (13) it follows that:

[00008]$\begin{array}{cc}\frac{V_{D2.\mathrm{REG},\mathrm{IP}1}}{V_{D1.\mathrm{REG},\mathrm{IP}1}}=\frac{{\left(\frac{{\mathrm{dI}}_{D2.\mathrm{REG},\mathrm{IP}1}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D2.\mathrm{REG},\mathrm{RP}1}}}{{\left(\frac{{\mathrm{dI}}_{D1.\mathrm{REG},\mathrm{IP}1}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D1.\mathrm{REG},\mathrm{RP}1}}}.& \left(14\right)\end{array}$

[0115] By a comparison of the relative volume flow rate

[00009]$\frac{V_{D2.\mathrm{REG},\mathrm{IP}1}}{V_{D1.\mathrm{REG},\mathrm{IP}2}}$

for the first spatial position of interest IP1 with a relative volume flow rate

[00010]$\frac{V_{D2.\mathrm{REG},\mathrm{IP}2}}{V_{D1.\mathrm{REG},\mathrm{IP}2}}$

of a second spatial position of interest IP2, a flow rate FR.sub.IP1,IP2 may be determined by equation (15):

[00011]$\begin{array}{cc}{\mathrm{FR}}_{\mathrm{IP}1,\mathrm{IP}2}=\frac{\left[\frac{V_{D2.\mathrm{REG},\mathrm{IP}1}}{V_{D1.\mathrm{REG},\mathrm{IP}1}}\right]}{\left[\frac{V_{D2.\mathrm{REG},\mathrm{IP}2}}{V_{D1.\mathrm{REG},\mathrm{IP}2}}\right]}=\frac{\left[\frac{{\left(\frac{{\mathrm{dI}}_{D2.\mathrm{REG},\mathrm{IP}1}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D2.\mathrm{REG},\mathrm{RP}1}}}{{\left(\frac{{\mathrm{dI}}_{D1.\mathrm{REG},\mathrm{IP}1}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D1.\mathrm{REG},\mathrm{RP}1}}}\right]}{\left[\frac{{\left(\frac{{\mathrm{dI}}_{D2.\mathrm{REG},\mathrm{IP}2}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D2.\mathrm{REG},\mathrm{RP}2}}}{{\left(\frac{{\mathrm{dI}}_{D1.\mathrm{REG},\mathrm{IP}2}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D1.\mathrm{REG},\mathrm{RP}2}}}\right]}.& \left(15\right)\end{array}$

[0116] In this case, the second spatial position of interest IP2 may refer to a further spatial position in the at least one vessel section V, which is different from the first spatial position of interest IP1. The second spatial reference position RP2 may be arranged downstream of the second spatial position of interest IP2 in the at least one vessel section V. In particular, the first RP1 and the second reference position RP2 may be the same or different.

[0117] For the second spatial position P2 as the first position of interest IP1, the third spatial position P3 as the first reference position RP1 and as the second position of interest IP2, a relative flow rate FR.sub.P2,P3 is produced:

[00012]$\begin{array}{cc}\frac{\left[\frac{V_{D2.\mathrm{REG},P2}}{V_{D1.\mathrm{REG},P2}}\right]}{\left[\frac{V_{D2.\mathrm{REG},P3}}{V_{D1.\mathrm{REG},P3}}\right]}=\frac{\left[\frac{{\left(\frac{{\mathrm{dI}}_{D2.\mathrm{REG},P2}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D2.\mathrm{REG},P3}}}{{\left(\frac{{\mathrm{dI}}_{D1.\mathrm{REG},P2}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D1.\mathrm{REG},P3}}}\right]}{\left[\frac{{\left(\frac{{\mathrm{dI}}_{D2.\mathrm{REG},P3}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D2.\mathrm{REG},\mathrm{RP}2}}}{{\left(\frac{{\mathrm{dI}}_{D1.\mathrm{REG},P3}}{\mathrm{dt}}\right)}_{t_{\mathrm{BAT},D1.\mathrm{REG},\mathrm{RP}2}}}\right]},& \left(16\right)\end{array}$

wherein RP2 is arranged downstream from third spatial position P3.

[0118] FIG. 9 shows a schematic diagram of an advantageous form of embodiment of a proposed provision unit PRVS. Advantageously, the provision unit PRVS may include a computing unit CU, a memory unit MU, and/or an interface IF. In this case, the provision unit PRVS, in particular the components of the provision unit PRVS, may be embodied for carrying out the individual acts of the proposed method for provision PROV-CD of a comparison dataset CD. In particular, the interface IF may be embodied for provision of the time-resolved first and second dataset PROV-D1, PROV-D2 and for provision of the comparison dataset PROV-CD. The computing unit CU and/or the memory unit MU may further be embodied for spatial SREG-D1-D2 and temporal registration TREG-D1-D2 of the first dataset D1 and second dataset D2, as well as for identification of the difference ID-DIFF between the first and second contrast medium flow.

[0119] FIG. 10 shows, as an example for a proposed medical imaging device, a schematic diagram of a medical C-arm x-ray device 37. Here, the medical C-arm x-ray device 37 advantageously includes a detector 34, in particular an x-ray detector, and an x-ray source 33. Advantageously, the medical C-arm x-ray device 37 may be embodied for recording and/or for provision of the first D1 and second dataset D2. In particular, the medical C-arm x-ray device may be embodied for recording the first image data ID1 including the number of first projection images of the examination object 31 and for recording the second image data ID2 including the number of second projection images of the examination object 31.

[0120] For recording the first and second projection images, an arm 38 of the C-arm x-ray device 37 may be supported for movement about one or more axes. The medical C-arm x-ray device 37 may further include a movement apparatus 39, which makes it possible to move the C-arm x-ray device 37 in the room. The provision unit PRVS for recording the first and the second projection images from the examination object 31 arranged on a patient support facility 32, may further send a signal 24 to the x-ray source 33. Subsequently, the x-ray source 33 may emit an x-ray bundle. When the x-ray bundle, after interacting with the examination object 31, strikes a surface of the detector 34, the detector 34 may send a signal 21 to the provision unit PRVS. The provision unit PRVS may receive the first and the second projection images with the aid of the signal 21.

[0121] Furthermore, the system may have an input unit 42, (e.g., a keyboard), and the display facility 41, (e.g., a monitor and/or display). The input unit 42 may be integrated into the display facility 41, for example, with a capacitive and/or resistive input display. In this case, an entry of a medical operator at the input unit 42 makes possible a control of the medical C-arm x-ray device 37, in particular of the proposed method for provision PROV-CD of a comparison dataset CD. For this, the input unit 42 may send a signal 26 to the provision unit PRVS, for example.

[0122] The display apparatus 41 may advantageously be embodied, in particular for overlaid or side-by-side display of a graphical representation of the registered first D1.REG and/or second dataset D2.REG and/or of the comparison dataset CD, in particular of the at least one parameter characterizing the difference P.DIFF. For this, the provision unit PRVS may send a signal 25 to the display apparatus 41. The at least one display parameter of the display apparatus 41 may further be configured to display graphical representations as a function of the comparison dataset CD, in particular of the at least one parameter characterizing the difference P.DIFF, for example, by color coding.

[0123] The schematic diagrams contained in the described figures do not in any way depict a measure of size or relationship of size.

[0124] In conclusion, it is pointed out once again that the methods and apparatuses described in detail above merely involve exemplary embodiments, which may be modified by the person skilled in the art in a wide variety of ways, without departing from the area of the disclosure. Furthermore, the use of the indefinite article “a” or “an” does not exclude the features concerned also being able to be present a number of times. Likewise, the terms “unit” and “apparatus” do not exclude the components concerned including a number of interoperating sub-components, which may also be spatially distributed.

[0125] It is to be understood that the elements and features recited in the appended claims may be combined in different ways to produce new claims that likewise fall within the scope of the present disclosure. Thus, whereas the dependent claims appended below depend on only a single independent or dependent claim, it is to be understood that these dependent claims may, alternatively, be made to depend in the alternative from any preceding or following claim, whether independent or dependent, and that such new combinations are to be understood as forming a part of the present specification.

[0126] While the disclosure has been illustrated and described in detail with the help of the embodiments, the disclosure is not limited to the disclosed examples. Other variations may be deduced by those skilled in the art without leaving the scope of protection of the claimed disclosure.