JP2006109960A - Medical image displaying method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To predict a return and functions of a graft of a liver excised from a donor needed in a living liver transplantation or the like. <P>SOLUTION: A medical image displaying method includes a process of extracting a specific area of an internal organ by using a medical image of a subject acquired by a medical image diagnostic apparatus and specifying an artery dominating area 24 of the internal organ by utilizing position information of circulatory organs including inflow blood vessels flowing into the extracted specific area and a vein dominating area 32 of the internal organ by utilizing position information of the circulatory organs including outflow blood vessels flowing out of the extracted specific area, a process of calculating a return area 40 from the artery dominating area 24 and the vein dominating area 32, and a process of displaying the calculated return area 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medical image display method and apparatus for supporting partial transplantation of an organ in a living body, and in particular, provides a simulation for supporting a plan when a doctor diagnoses or treats an organ such as a liver in clinical practice. The present invention relates to a medical image display method and apparatus.

  In recent years, an image obtained by an abnormal image diagnostic apparatus such as an X-ray imaging apparatus, an X-ray CT apparatus, or an MRI apparatus has been actively used not only for diagnosis but also for treatment.

  For example, a method of extracting a specific region of an organ based on blood vessel running information in a single organ as disclosed in Patent Document 1 has been devised. Since it is based on anatomical information, a result very similar to a specific region judged by a doctor is obtained, and the simulation accuracy as a pre-organectomy plan is dramatically improved. For example, in surgery for removing liver cancer, a technique consistent with the above simulation method can often be employed.

The technique disclosed in Patent Document 1 is performed using information on one type of blood vessel. When an ablation region is determined by an artery, the perfusion control region in the artery is set relatively well. However, since no consideration is given to veins, when a vein is included in the region to be excised, the vein is excised without considering the perfusion-dominated region of the vein. That is, when a vein existing in the vicinity of the boundary is excised, a state occurs in which there is no vein to which blood in a region controlled by another artery not to be excised returns.
In the partial excision and partial transplantation of the organ, it is necessary to excise and transplant the vein-dominated region as described above. However, in the above method, calculation of the region is not considered.

Therefore, there is a method for specifying a control region in consideration of a venous perfusion control region as described in Japanese Patent Application No. 2003-135122 (referred to as “prior application”) filed by the patent applicant of the present case. As a result, the ablation region and the remaining region can be determined while grasping the normal perfusion governing structure.
JP 2001-283191 A

However, since the conventional method performs simulation using one vascular system, it is necessary to predict the reflux of a part of the liver tissue (graft) excised from a donor that is desired by living donor liver transplantation and the function of the graft. No consideration was given.
In other words, in the case of living donor liver transplantation currently performed in many facilities, the (partial) liver removed from the donor is called a graft, and it is necessary to guarantee the return (blood circulation route) within the graft. There is. Similarly, it is necessary to guarantee reflux in the liver (residual liver) left for the donor. That is, it is necessary to guarantee the function of the graft and the remaining liver, accurately estimate the necrosis range due to congestion and ischemia as a volume (numerical value), and keep it to the minimum.

  An object of the present invention is to provide a medical image display method and apparatus capable of predicting graft reflux and function.

  The object is to use a step of extracting a specific region of an organ using a medical image of a subject obtained by a medical image diagnostic apparatus and position information of a circulatory organ including an inflow blood vessel flowing into the extracted specific region. Identifying a first dominant region of the organ, and identifying a second dominant region of the organ using position information of a circulatory organ including an outflow blood vessel flowing out from the extracted specific region; This is achieved by including a step of calculating a return region from the first control region and the second control region, and a step of displaying the calculated return region.

Further, the first dominant region and the second dominant region may be specified by position information of a plurality of blood vessels.
Further, the first dominant region or the second dominant region may be specified by selectively combining the plurality of blood vessel information.
Further, the selective combination may be combined into an inflow system and an outflow system of blood vessels to specify the first dominant region or the second dominant region.

The method may further include a step of setting a boundary for specifying the organ, and the calculation step may calculate the reflux region further using the set boundary.
The first dominant region and the second dominant region may further include a step of superimposing and displaying on the organ.

  Furthermore, by using means for extracting a specific region of an organ using a medical image of a subject obtained by a medical image diagnostic apparatus and position information of a circulatory organ including an inflow blood vessel flowing into the extracted specific region Means for identifying the first dominant region of the organ, and means for specifying the second dominant region of the organ using position information of the circulatory organ including an outflow blood vessel flowing out from the extracted specific region; This is achieved by comprising means for calculating a return region from the first control region and the second control region, and means for displaying the calculated return region.

  The present invention can predict graft reflux and function.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the invention, and the repetitive description thereof is omitted.
As an embodiment, an X-ray CT image obtained by performing contrast imaging of the liver is used as a processing target image, and a procedure for specifying a region of the liver using arterial and venous travel information and a liver excision region using the procedure A method for displaying is described below.

  As shown in Fig. 1 (a), a plurality of tomographic images 11 obtained by an image diagnostic apparatus capable of three-dimensional measurement such as an X-ray CT apparatus and an MRI apparatus are stacked, and the stacked tertiary as shown in Fig. 1 (b) The original image 12 is used, and the processing target is three-dimensional. The stacked three-dimensional image 12 includes liver tissue, arteries, veins, tumors, and the like, and is displayed on a monitor, for example, as a pseudo three-dimensional image that is shaded and projected on a two-dimensional projection surface (not shown).

  FIG. 2 is a diagram for explaining simulation information used in the present invention. In order to simplify the explanation, it is shown as a plan view. Assuming blood circulation between the blood vessels 21 and 25 inside the organ 20, for example, if the blood vessel 21 is ligated at the position 23, according to Patent Document 1, the dominant region of the blood vessel 22 is, for example, 24. Desired. Anatomically, the branch 26 of the blood vessel 25 where reflux is observed travels around approximately 24 boundaries (edges).

  Here, if the blood vessel 25 is ligated at the position 31 as shown in FIG. 3, the dominant region of the blood vessel 26 is obtained by Patent Document 1 as 32, for example. Anatomically, the branches 22 and 33 of the blood vessel 21 in which reflux is recognized run around the boundary (end) of about 32.

  FIG. 4 shows an example in which the dominant region obtained in FIGS. 2 and 3 is displayed simultaneously. The dominant area is roughly divided into three areas. It can be estimated that the region where there is a reflux between the branch 22 of the blood vessel 21 and the branch 26 of the blood vessel 25 is an overlapping portion 40 of the respective control regions. That is, if the region where the dominant regions 24 and 32 are combined is a graft in living liver transplantation, and the branches 22 and 26 are reconstructed, the region where reflux normally functions is 40, and the other regions are congested or ischemic. It can be estimated that this is a region where reflux does not function normally. The exact volume of region 40 will more accurately estimate 1% of the recipient's body weight, which is the appropriate graft volume for living liver transplant recipients, as the graft volume where normal function of reflux can be expected.

  Also, in the actual operation as shown in FIG. 5, the separation plane assumed by the surgeon is set as 51, and when the left side of this figure is used as a graph, the region 40 obtained in FIG. It will be divided into 53. In this case as well, the region where reflux can be estimated to function normally is only 53, and 52 is recognized as a region where reflux does not function normally and is excluded from the graft volume where normal function can be expected. Function estimation is possible.

  Although it is the calculation method of a reflux region, the method of calculating using a logical operation can be considered, for example. Assuming that the region dominated by the vascular system An is San, the region dominated by the vascular system Bn is Sbn, and the resection organ side by the physical section assumed by the surgeon is Co, the required reflux region is

として求められる。このようにして求められた還流領域を半透明表示などで擬似三次元画像として提示することで、視覚的に還流域を把握させることができる。

As required. By presenting the reflux region thus obtained as a pseudo three-dimensional image with a translucent display or the like, the reflux region can be visually grasped.

  In addition, when there are multiple types of vessels, organs can be classified into inflow and outflow blood vessels, so not only the return region is calculated by combining inflow and outflow blood vessels one by one, For different blood vessels, the inflow system and the outflow system can be combined as the An and Bn, respectively, and calculated as a composite reflux region.

   FIG. 6 shows a screen configuration example for performing the main measurement. In the region 60, a processing result image for selecting a simulation result of a certain vascular system (for example, only one type such as an artery) is displayed. As a result of processing, even in 3D of only the dominant region and the dominant vessel, a check box 61 is added to the image of the dominant vessel in the entire liver to visually distinguish it. Further, a scroll bar 62 for scrolling the display area 60 is provided so that a plurality of simulation results can be displayed. Multiple groups of 60 are displayed for each vessel or manually set noodles, and used to calculate the reflux region in combination. The combined reflux region is displayed as a pseudo three-dimensional image 63 while rotating in an arbitrary direction or changing the image reconstruction method. Also, in the same way as in the prior art, a controller is installed in 64 for displaying, hiding, and changing the display color of the organ substance and blood vessels used in the simulation, the dominant region and the reflux region. In 65, the calculation result of the reflux region is displayed. For example, in the case of living liver transplantation, when the recipient weight is given, the calculation result related to it is also displayed. Further, when a given blood vessel is known as an artery, vein, or the like, the non-perfusion area can be displayed as a congestion candidate area, an ischemia candidate area, or the like, respectively. In this case, it is also possible to display the congestion candidate area and the ischemia candidate area together with 63. Also, for example, a check box for identifying a region due to an inflow system blood vessel, a region due to an outflow system blood vessel, and a manual region as indicated by 66 is provided.

  FIG. 7 shows an example of the flow of this calculation. First, information necessary for simulation, such as donor weight and recipient weight, is set as an initial parameter. Using the screen shown in FIG. 6, the operator selects, for example, a check box 61 to control a region that is a vascular branch candidate that is a return region candidate. The selected dominant region is displayed at 63 as a pseudo three-dimensional image. The assumed reflux volume is calculated sequentially and the result is displayed at 65. The display form and non-display part of the pseudo 3D image are set using 60 check boxes and the controller 64. If there is a problem with the display, repeat 76. If the selection of the dominant region of each vascular branch that is a return region candidate is not completed, the operation after 72 is performed again, and this operation is repeated until a desired result is obtained.

  FIG. 8 shows a configuration diagram of an example of hardware capable of realizing the system of the present invention. This system includes a CPU 82, a main memory 80, a magnetic disk 81, a display memory 83, a display 84, a controller 85, a mouse 86, a keyboard 87, and a common bus 88. Each tomographic image is stored in the magnetic disk 81, and the CPU 82 performs predetermined processing according to the projection display software in the main memory 80. In this processing, input / output processing and processing operations are performed using the mouse 86 and keyboard 87 added to the controller 85. The stacked three-dimensional image and the processing result are displayed on the display 84 via the display memory 83, and the processing of FIG. 7 is performed using the operation of the operator, and an image that meets various conditions is displayed. The processing result and display contents are stored in the magnetic disk 81 and used for redisplay.

  Although the embodiments of the present invention have been described above, the method of the present invention is applicable not only to X-ray CT apparatuses but also to images acquired by other image diagnostic apparatuses such as magnetic resonance imaging apparatuses and ultrasonic diagnostic apparatuses. Can be used. In addition to the liver described in the above embodiment, the target organ can be applied to many parts of the human body.

According to the medical image display method and apparatus of the present invention, it is possible to estimate a normal functional range in an excised organ portion even in an organ containing a complicatedly running vessel. That is, in the conventional methods, a plurality of dominating regions due to a single vascular system are simulated, and the perfusion is estimated sensuously, but this device can visualize the estimated region.
This enables a numerical and visual approach of calculating and visualizing the volume of the recirculation region of the resected organ for an organ containing a complex running vessel.

The figure which shows the relationship between a tomogram and data. The figure explaining the control area | region by the blood vessel branch required for this invention. The figure explaining the control area | region by the blood vessel branch required for this invention. The figure explaining the reflux region calculated by the present invention. The figure explaining the reflux region calculated by the present invention. The figure explaining the screen utilized by this invention, and a required function. The flowchart explaining an example of the flow of a process of this invention. The figure which shows the hardware structural example which can implement this invention.

Explanation of symbols

  11 tomographic images, 12 stacked 3D images, 20 organs, 21, 22 arteries, 23 arterial ligation positions, 24 arterial dominating regions, 25,26 veins, 31 venous ligating regions, 32 venous dominating regions, 33 arteries, 40 reflux regions, 51 Expected resection line by surgeon, 52 Expected resection area in recirculation zone, 53 Recirculation area finally required

Claims (7)

Extracting a specific region of an organ using a medical image of a subject obtained by a medical image diagnostic apparatus;
Identifying a first dominant region of the organ using position information of a circulatory organ including an inflow blood vessel flowing into the extracted specific region;
Identifying a second dominant region of the organ using position information of a circulatory organ including an outflow blood vessel flowing out from the extracted specific region;
Calculating a reflux region from the first dominant region and the second dominant region;
Displaying the calculated reflux region. A medical image display method comprising:   The medical image display method according to claim 1, wherein the first dominant region and the second dominant region are specified by position information of a plurality of blood vessels.   The medical image display method according to claim 2, wherein the first dominant region or the second dominant region is specified by selectively combining from the plurality of blood vessel information.   The medical image display method according to claim 3, wherein the selective combination is grouped into an inflow system and an outflow system of a blood vessel to specify the first dominant region or the second dominant region.   The medical image display method according to claim 1, further comprising a step of setting a boundary for specifying the organ, wherein the calculation step calculates the reflux region further using the set boundary. .   The medical image display method according to claim 1, further comprising a step of displaying the first dominant region and the second dominant region so as to be superimposed on the organ. Means for extracting a specific region of an organ using a medical image of a subject obtained by a medical image diagnostic apparatus;
Means for identifying a first dominant region of the organ using position information of a circulatory organ including an inflow blood vessel flowing into the extracted specific region;
Means for identifying a second dominant region of the organ using positional information of a circulatory organ including an outflow blood vessel flowing out from the extracted specific region;
Means for calculating a reflux region from the first dominant region and the second dominant region;
A medical image display device comprising: means for displaying the calculated reflux region.

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