JP2014076091A - Medical image processor, image diagnostic device and medical image processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical image processor capable of more effectively observing a tubular structure, such as a bronchial tube and a blood vessel.SOLUTION: A medical image processor relating to an embodiment includes a branch extraction part and an image generation part. The branch extraction part respectively extracts branch positions of tubular structures from a plurality of three-dimensional volume data of branched tubular structures collected in states different from each other of a subject. The image generation part generates image data for separately comparing the tubular structures to be segmented into a plurality of areas at the branch positions among the different states in each area.

Description

  Embodiments described herein relate generally to a medical image processing apparatus, an image diagnostic apparatus, and a medical image processing program.

  Conventionally, bronchial imaging has been performed by an image diagnostic apparatus in order to confirm whether or not the lung bronchus is hard due to bronchiectasis or the like. Further, a technique for extracting a bronchial region from three-dimensional (3D) volume data and identifying a bronchus core line or a bifurcation has been proposed. Similarly, a technique for identifying a core wire or a branching portion of a blood vessel has been proposed.

JP 2012-96024 A

  An object of the present invention is to provide a medical image processing apparatus, an image diagnostic apparatus, and a medical image processing program capable of more effectively observing tubular structures such as bronchi and blood vessels.

A medical image processing apparatus according to an embodiment of the present invention includes a branch extraction unit and an image generation unit. The branch extraction unit extracts branch positions of the tubular structures from a plurality of three-dimensional volume data of the branched tubular structures collected in different states of the subject. An image generation part produces | generates the image data for comparing separately the said tubular structure segmented into a some area | region by the said branch position for every said area | region between the said different states.
An image diagnostic apparatus according to an embodiment of the present invention includes the medical image processing apparatus and an image data collection system. The image data collection system collects biological signals from the subject in the different states, and acquires the three-dimensional volume data based on the collected biological signals.
In addition, the medical image processing program according to the embodiment of the present invention causes a computer to function as a branch extraction unit and an image generation unit. The branch extraction unit extracts branch positions of the tubular structures from a plurality of three-dimensional volume data of the branched tubular structures collected in different states of the subject. An image generation part produces | generates the image data for comparing separately the said tubular structure segmented into a some area | region by the said branch position for every said area | region between the said different states.

1 is a configuration diagram of an image diagnostic apparatus including a medical image processing apparatus according to an embodiment of the present invention. The figure which shows the example which extracted the core line and branch position of the bronchus from the volume data of the bronchus in the expiration state, and the volume data of the bronchus in the inhalation state in the branch extraction part shown in FIG. The figure which shows the example which produced | generated SPR image data so that the several area | region of the bronchus segmented by the branch position as shown in FIG. 2 can be compared between an expiration state and an inhalation state. FIG. 3 is a diagram showing an example in which the lengths and thicknesses of a plurality of bronchial regions segmented by branch positions are compared and displayed as a bar graph as shown in FIG. 2. The figure which shows the example which displayed the rectangular frame which comprises the bar graph shown in FIG. 4 on a CPR image superimposed. The flowchart which shows the flow in the case of imaging a bronchus with the medical image processing apparatus and image diagnostic apparatus shown in FIG.

  A medical image processing apparatus, an image diagnosis apparatus, and a medical image processing program according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram of an image diagnostic apparatus including a medical image processing apparatus according to an embodiment of the present invention.

  The diagnostic imaging apparatus 1 includes a medical image processing apparatus 2. However, the medical image processing apparatus 2 may be an apparatus independent of the image diagnostic apparatus 1, and the medical image processing apparatus 2 may be connected to the image diagnostic apparatus 1 via a network. Further, the diagnostic imaging apparatus 1 includes an input device 3, a display device 4, and an image data collection system 5.

  The diagnostic imaging apparatus 1 includes an X-ray CT (computed tomography) apparatus, a magnetic resonance imaging (MRI) apparatus, a positron emission computed tomography (PET) apparatus, and a single photon emission computed tomography (SPECT). Single photon emission computed tomography) and other nuclear medicine diagnostic equipment.

  Therefore, the image diagnostic apparatus 1 is provided with the image data collection system 5 corresponding to the type. The image data collection system 5 is a system that acquires biological signals such as X-ray detection data and MR signals from the subject, and generates medical image data of the subject based on the acquired biological signals.

  In particular, the image data collection system 5 is configured to collect biological signals from the subject in different states of the subject and to acquire a plurality of 3D volume data of the branched tubular structure based on the collected biological signals. Is done. Examples of the branched tubular structure include blood vessels such as bronchi and coronary arteries of the heart. Further, different states include an inhalation state and an expiration state for the bronchi, and a diastole and a systole of the myocardium for the blood vessels.

  The image data collection system 5 includes SPR (Stretched Curved Multiple Planer Reconstruction) image data, CPR (Curved Multiple Planer Reconstruction) image data, volume rendering (VR) image data, A function of generating two-dimensional (2D) image data for display such as maximum intensity projection (MIP) image data and a function of causing the display device 4 to output the generated 2D image data are also provided. Further, the image data collection system 5 uses the pattern matching processing of 2D image data or volume data to correspond to different states of the subject and to display 2 frames of 2D image data corresponding to the same imaging region on the display device 4. It is configured so that it can be displayed in comparison.

  The medical image processing apparatus 2 can be constructed by causing a computer to read a medical image processing program. However, a circuit may be used to configure the medical image processing apparatus 2. The medical image processing program can be recorded on an information recording medium and distributed as a program product so that a general-purpose computer can be used as the medical image processing apparatus 2. Of course, the medical image processing program can be downloaded to a computer via a network without using an information recording medium.

  The medical image processing apparatus 2 includes a branch extraction unit 6, an image generation unit 7, and a measurement unit 8. Therefore, when the medical image processing apparatus 2 is configured by a computer, the medical image processing program causes the computer to function as the branch extraction unit 6, the image generation unit 7, and the measurement unit 8.

  The branch extraction unit 6 acquires a plurality of 3D volume data of a branched tubular structure corresponding to different states of the subject from the image data collection system 5, and determines a branch position of the tubular structure from each of the plurality of 3D volume data. Has a function to extract.

  FIG. 2 is a diagram illustrating an example in which the branch extraction unit 6 illustrated in FIG. 1 extracts the bronchus core line and the branch position from the bronchial volume data in the expired state and the bronchial volume data in the inhaled state, respectively.

  FIG. 2 (A) shows bronchial 3D volume data in the expired state, and FIG. 2 (B) shows bronchial 3D volume data in the inspiratory state. As shown in FIG. 2, the branch extraction unit 6 can extract the branch position of the bronchus from a plurality of 3D volume data of the branching bronchus collected in the inhalation state and the expiration state of the subject.

  More specifically, the bronchial core line can be extracted as indicated by a two-dot chain line by a known process such as a threshold process or an edge detection process for the pixel value of each 3D volume data. Also, as indicated by the solid line, the bronchial wall can be extracted from each 3D volume data. Further, in each 3D volume data, the intersection of the core lines can be obtained as a branch point.

  Then, the plane passing through the branch point of the core line in each 3D volume data can be obtained as the branch position of the bronchus. For example, the bronchial bifurcation plane can be defined by an arbitrary method, such as a plane perpendicular to the core line of interest or a cross section of a portion where the thickness of the bronchial wall changes as the bronchial bifurcation position. In addition, pattern matching using a bronchus core line is possible.

  In the example shown in FIG. 2, the bronchi in the expired state and the bronchus in the inhaled state are divided into four regions of the first segment, the second segment, the third segment, and the fourth segment that are continuous with each other with a branch plane indicated by a dotted line as a boundary. It is segmented.

  The image generation unit 7 has a function of generating image data for separately comparing the tubular structures segmented into a plurality of regions according to the branch positions extracted by the branch extraction unit 6 for each region between different states. . For this purpose, the image generation unit 7 has a function of performing pattern matching of 3D volume data or 2D image data corresponding to a plurality of different states, and associating the core lines of each region segmented by the branch position between the plurality of states. It is done.

  The image data for comparing the segmented tubular structure for each region can be any 2D image data that can be generated from the volume data. Specific examples include 2D image data such as SPR image data, CPR image data, VR image data, and MIP image data.

  FIG. 3 is a diagram illustrating an example in which SPR image data is generated so that a plurality of regions of the bronchus segmented by the branch position as illustrated in FIG. 2 can be compared between the expiration state and the inspiration state.

  As shown in FIG. 3, an SPR image can be displayed for each segmented bronchial region and respiratory state. Specifically, an exhaled SPR image in which only the first segment of the bronchus is depicted and an inhaled SPR image can be displayed in parallel. Similarly, for the second segment, the third segment, and the fourth segment, the SPR image in the expiration state and the SPR image in the inspiration state can be displayed in parallel for each segment.

  As illustrated in FIG. 3, the image generation unit 7 can generate SPR image data having a branch position as a boundary as image data for comparing at least one of a plurality of segmented regions. For this purpose, pattern matching for associating the cores of corresponding regions between different states is executed.

  The measurement unit 8 has a function of measuring at least one of the length and thickness of the plurality of regions divided by the segments at the branch position of the tubular structure for each different state of the subject, and at least for each different state. A function of generating display data for comparing and displaying at least one of the length and the thickness of one region as a graph between different states.

  FIG. 4 is a diagram showing an example in which the lengths and thicknesses of a plurality of bronchial regions segmented by branch positions are compared and displayed as bar graphs as shown in FIG.

  In FIG. 4, the vertical axis indicates the length of each segmented bronchus region. As shown in FIG. 4, a bar graph can be created so that the lengths of the first segment, the second segment, the third segment, and the fourth segment can be compared between the expiration state and the inspiration state, respectively. The thickness of each bar graph represents the thickness of each segment. The thickness of the bronchus may be expressed by any index such as diameter, radius, maximum diameter, average diameter, cross-sectional area, and the like. Therefore, in the bar graph shown in FIG. 4, both the length and the thickness of each region of the bronchus can be compared between the expiration state and the inspiration state.

  As described above, the display unit 8 can generate display data for comparatively displaying at least one of the length and the thickness of at least one of the plurality of regions as a bar graph. And the display data produced | generated in the measurement part 8 can be output to the display apparatus 4. FIG. In addition, you may make it produce | generate the display data for displaying the line graph which shows the length of each area | region, and the linear bar graph without thickness.

  Furthermore, the measurement unit 8 has a function of generating image data for superimposing and displaying a figure or a diagram constituting the graph at a corresponding position of the tubular structure, together with the form of the tubular structure. Examples of the image data representing the shape of the tubular structure include 2D image data such as SPR image data, CPR image data, VR image data, and MIP image data as described above.

  FIG. 5 is a diagram illustrating an example in which a rectangular frame constituting the bar graph shown in FIG. 4 is superimposed and displayed on a CPR image.

  As shown in FIG. 5, a rectangular frame indicating the length and thickness of each region of the bronchus in the expired state can be superimposed and displayed on the CPR image of the bronchus in the expired state. Similarly, a rectangular frame indicating the length and thickness of each region of the bronchus in the inhalation state can be superimposed and displayed on the CPR image of the bronchus in the inhalation state. In other words, the measurement unit 8 can generate image data for causing the display device 4 to display an image as exemplified in FIG.

  Next, operations and actions of the medical image processing apparatus 2 and the image diagnostic apparatus 1 will be described. Here, a case where imaging of the bronchi that branches in the inhalation state and the expiration state of the subject is performed will be described as an example.

  FIG. 6 is a flowchart showing a flow when the medical image processing apparatus 2 and the image diagnosis apparatus 1 shown in FIG. 1 perform bronchial imaging.

  First, in step S1, 3D volume data of the lung field in the expired state and the inhaled state of the subject is collected by the diagnostic imaging apparatus 1. If the diagnostic imaging apparatus 1 is an X-ray CT apparatus, multi-slice X-ray CT image data or 3D X-ray CT image data using the lung field as an imaging region is collected as volume data in the expired state and the inhaled state, respectively.

  Specifically, X-ray detection data from an imaging region including a lung field in an expiration state and an inspiration state by an X-ray detector provided in the image data acquisition system 5 or a biological signal sensor such as a radio frequency (RF) coil. And biological signals such as MR signals are acquired. Then, in the image data collection system 5, volume data of a region including the lung field is generated for each respiratory state by image reconstruction processing based on the biological signal.

  Next, in step S <b> 2, the branch extraction unit 6 of the medical image processing apparatus 2 acquires volume data in the expiration state and the inspiration state of the region including the target bronchus from the volume data collected in the image data collection system 5.

  Next, in step S3, the branch extraction unit 6 extracts a region occupied by the bronchus from the acquired volume data by image processing such as edge extraction processing and threshold processing.

  Next, in step S4, the branch extraction unit 6 extracts the extracted bronchial core line and the branch point of the core line. Thereby, as shown in FIG. 2, the bronchus can be segmented into a plurality of regions without branching.

  Next, in step S5, the branch extraction unit 6 extracts a bronchial wall based on the extracted bronchial region and the core line. Thereby, the outline of the bronchus is specified. Further, the bronchi can be extracted and displayed for each segmented region.

  Next, in step S6, the branch extraction unit 6 performs pattern matching between the core line of the bronchus in the expired state and the core line of the bronchus in the inhaled state. Thereby, each area | region of the bronchus in an expiration state and each area | region of the bronchus in an inhalation state can be matched mutually.

  That is, in the example shown in FIG. 2, the first segment of the bronchus in the expired state and the first segment of the bronchus in the inhaled state can be associated with each other. Similarly, each region from the second segment to the fourth segment can be associated with the bronchial volume data in the expired state and the bronchial volume data in the inhaled state.

  The core matching process may be executed prior to the bronchial wall extraction process in step S5.

  Next, in step S7, the branch extraction unit 6 compares the areas associated with each other between the bronchial volume data in the expired state and the bronchial volume data in the inhaled state, such as 2D SPR image data. Display image data is generated. The generated 2D display image data is output to the display device 4. Thereby, a medical image such as an SPR image to be compared between the expiration state and the inspiration state is displayed on the display device 4 for each bronchial segment as shown in FIG.

  Next, in step S8, the measurement unit 8 measures the length and thickness of the plurality of regions divided by the segments at each branch position of the bronchus for the expiration state and the inspiration state, respectively. The thickness and length of each region can be measured by measuring the distance between the bronchial walls extracted by the branch extraction unit 6.

  Furthermore, the measurement unit 8 generates display data for comparison display between the expiration state and the inhalation state as a graph of the length and thickness of each region. Then, the measurement unit 8 causes the display device 4 to output the generated display data. As a result, a graph such as a bar graph shown in FIG. 4 is displayed on the display device 4.

  Next, in step S8, the measurement unit 8 generates 2D display image data for fusion-displaying a figure such as a rectangular frame constituting the graph on morphological image data such as bronchial CPR image data. Then, the measurement unit 8 causes the display device 4 to output the generated 2D display image data. Thereby, the display device 4 can display a morphological image such as a CPR image in which a rectangular frame of a bar graph is superimposed at a corresponding position of the bronchus as shown in FIG.

  That is, the medical image processing apparatus 2 and the diagnostic imaging apparatus 1 as described above correspond to different states of a subject such as an expired state and an inhaled state, and from volume data in which a branched tubular structure such as a bronchus is depicted. The core line and the branch point of the tubular structure are extracted so that changes between different states can be observed for each region segmented by the branch point.

  For this reason, according to the medical image processing apparatus 2 and the diagnostic imaging apparatus 1, an image such as an SPR image can be generated for each branch of a blood vessel or bronchus and compared between different states. In particular, by comparing and displaying different states as CPR images and SPR images, it is possible to easily grasp which part of the tubular structure has moved between different states. Furthermore, according to the medical image processing apparatus 2 and the diagnostic imaging apparatus 1, it is possible to display a graph representing the length and thickness of each branch such as a bronchus or to superimpose a graph on a CPR image. For this reason, it is effective for examinations such as bronchiectasis.

  Although specific embodiments have been described above, the described embodiments are merely examples, and do not limit the scope of the invention. The novel methods and apparatus described herein can be implemented in a variety of other ways. Various omissions, substitutions, and changes can be made in the method and apparatus described herein without departing from the spirit of the invention. The appended claims and their equivalents include such various forms and modifications as are encompassed by the scope and spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Image diagnostic apparatus 2 Medical image processing apparatus 3 Input apparatus 4 Display apparatus 5 Image data collection system 6 Branch extraction part 7 Image generation part 8 Measurement part

Claims (9)

A branch extraction unit for extracting a branch position of the tubular structure from a plurality of three-dimensional volume data of the branched tubular structure collected in different states of the subject;
An image generating unit that generates image data for separately comparing the tubular structure segmented into a plurality of regions according to the branch position between the different states for each region;
A medical image processing apparatus comprising:   The image generation unit is configured to generate Stretched Curved Multiple Planer Reconstruction image data having the branch position as a boundary as image data for comparing at least one of the plurality of regions between the different states. The medical image processing apparatus according to claim 1.   The medical image processing apparatus according to claim 1, further comprising a measurement unit that measures at least one of a length and a thickness of each of the plurality of regions for each of the different states.   The said measurement part is comprised so that at least one of the length and thickness of the said at least 1 area | region for every said different state may be produced | generated as a graph, and the display data for making it display comparatively between the said different states are generated. The medical image processing apparatus described.   The medical image processing apparatus according to claim 4, wherein the measurement unit is configured to generate display data for comparing and displaying at least one of a length and a thickness of the at least one region as a bar graph.   The said measurement part is comprised so that the image data for making the figure or diagram which comprises the said graph superimposed on the corresponding position of the said tubular structure with the form of the said tubular structure may be produced | generated. Or the medical image processing apparatus of 5.   The branch extraction unit is configured to extract the branch position of the bronchus from a plurality of three-dimensional volume data of the branching bronchus collected in the inhalation state and the expiration state of the subject. The medical image processing apparatus according to any one of the above. The medical image processing apparatus according to any one of claims 1 to 7,
An image data collection system for collecting biological signals from the subject in the different states and acquiring the three-dimensional volume data based on the collected biological signals;
An image diagnostic apparatus comprising: Computer
A branch extraction unit that extracts a branch position of the tubular structure from a plurality of three-dimensional volume data of the branched tubular structure collected in different states of the subject, and is divided into a plurality of regions by the branch position. An image generation unit for generating image data for separately comparing the tubular structures for each region between the different states;
Medical image processing program to function as

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