JP4801892B2 - Medical image display device - Google Patents

Description

The present invention generates and displays a morphological image from a medical imaging apparatus such as an X-ray computed tomography apparatus (CT scanner) or a magnetic resonance imaging apparatus (MRI) and a volume data file collected by the medical imaging apparatus. The present invention relates to a medical image display apparatus.

In recent X-ray computed tomography apparatuses (CT scanners), magnetic resonance imaging apparatuses (MRI), and the like, for example, a slice including the heart and brain can be repeatedly imaged with a relatively high time resolution. Functional information such as blood flow is calculated from such dynamic data, and a functional map (functional image) obtained by color-coding the calculation result is superimposed on a morphological image and displayed in color. However, the conventional system merely displays the result calculated for slice data at a specific position in a superimposed manner. From the clinical field, there has been a demand for receiving functional information even in 3D images and MPR images. However, complicated operations were required for this purpose.
JP 2003-190148 A

An object of the present invention is to display a morphological image generated from a volume data file together with function information in a medical image display device and a medical image photographing device .

According to another aspect of the present invention, there is provided a medical image display apparatus that includes a first volume data file collected for a brain tissue area by an X-ray computed tomography apparatus and a brain tissue area by dynamic scanning of the X-ray computed tomography apparatus. Storage means for storing a series of temporally continuous second volume data files collected under blood vessel enhancement as a target, and three-dimensional data for generating three-dimensional morphological image data relating to blood vessels from the first volume data file A morphological image generation unit, means for generating a three-dimensional functional map relating to a blood flow dynamic index of the brain tissue region from the series of second volume data files, and each pixel of the three-dimensional morphological image the value of the hemodynamic indicators of position on said corresponding three-dimensional functional map Therefore comprising means for imparting color information, means for generating a two-dimensional anatomical image by volume rendering process from the three-dimensional anatomical image of the color information has been granted, and means for displaying the form image.

According to the present invention, a morphological image generated from a volume data file can be displayed together with function information in a medical image display device and a medical image photographing device .

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment will be briefly described. When a morphological image such as a three-dimensional (3D) image or an MPR image is generated and displayed from a volume data file obtained from a medical image photographing apparatus such as a CT scanner or an MRI, the same object is displayed. A plurality of volume data files (referred to as dynamic data files) that are temporally continuous with respect to the same part of a specimen are automatically searched from the storage unit, and metabolism, exercise, etc. of organs and the like are performed from these volume data files. For example, blood flow is calculated as functional information (functional image (functional map)) representing the degree of function, and a morphological image is displayed according to the blood flow. That is, when a morphological image is generated and displayed from a desired volume data file, it is automatically colored according to the function information.

  By processing a volume data file that provides function information and a volume data file that provides configuration information, the characteristics of each data can be visualized simultaneously. When displaying a 3D volume rendering image, MPR image, dynamic data file, and blood vessel contrast image in a superimposed manner, the volume data file can be used to simultaneously observe the information on the morphological information and functional information (for example, blood flow) in real time. Thus, the diagnostic ability is dramatically improved for diagnosis of cerebral infarction and other vascular diseases. In addition, with the advent of real-time devices (CT scanners, MRIs, etc.), application of this device makes it possible to visualize functional information in real time, greatly contributing to medical development. Functional information can be captured in volume (stereoscopic) and in real time (dynamic), and combined with morphological information, the diagnostic ability is significantly improved over conventional devices.

  FIG. 1 shows the configuration of a medical image display apparatus according to this embodiment. FIG. 2 shows a processing procedure. Here, a CT scanner will be described as an example of the imaging apparatus. The volume data storage unit 1 stores a plurality of volume data files collected by the CT scanner. The volume data file is typically an aggregate of a plurality of slice data files. A plurality of volume data files with high time resolution are generated by rotating the cone beam X-ray tube and the two-dimensional array type large-field X-ray detector around the subject at high speed. Each volume data file is associated with accompanying information. The supplementary information includes items such as the subject name, subject ID, imaging region, imaging device type, imaging conditions, reconstruction conditions (reconstruction function, resolution, reconstruction slice thickness, etc.). Here, for convenience of explanation, it is assumed that a volume data file that mainly represents the morphology of soft tissue or bone with a natural CT value without interpolation of blood vessels is interpolated. Volume data files include a contrast data file in which a contrast medium is still in the subject and blood vessels are emphasized, or a bolus of contrast medium is injected into a bolus and changes in the concentration of the contrast medium over time. There is a dynamic data file for observing flow dynamics.

  The contrast image automatic search unit 2 searches for a desired contrast data file designated by the operator via an input device such as a mouse (not shown). The dynamic data automatic search unit 3 is based on the incidental information, and is the same dynamic data file as the desired volume data file designated by the operator and the same subject and the same part to be imaged. The plurality of volume-enhanced volume data files) are specified by searching the storage unit 1. The image data loading unit 4 loads the searched desired volume data file and the identified dynamic data file from the storage unit 1 to an internal memory (not shown). The image same position reference unit 5 matches the anatomical position between the volume data file and the identified dynamic data file based on the anatomically characteristic portion.

  The function information digitizing unit 6 calculates, as function information, for example, cerebral blood flow indexes of CBP, CBV, and MTT for each pixel (for each local region) from a plurality of volume data files constituting the dynamic data file. The spatial map of the index (functional map representing cerebral blood flow) is generated by the functional map creation color conversion unit 7. In practice, these indexes are calculated only in the blood vessel enhancement region that can be specified from the CT value. CBP represents the unit volume in the capillary of the brain tissue and the blood flow volume per unit time [ml / 100 ml / min], CBP represents the blood volume per unit volume in the brain tissue [ml / 100 ml], and MTT represents It represents the mean blood passage time [seconds] through the capillaries. In this CBP study, a contrast agent having no cerebral vascular permeability, such as an iodine contrast agent, is used as a tracer. The iodine contrast agent is injected from the cubital vein by an injector, for example. The iodine contrast medium intravenously injected by the injector flows into the cerebral artery via the heart and lungs. Then, the contrast medium flows out from the cerebral artery to the cerebral vein through the capillaries in the brain tissue. At this time, the iodine contrast medium passes through the capillary blood vessels in normal brain tissue without leaking out of the blood vessels. The state of passage of the contrast agent is imaged by dynamic CT, and the time density curve Ca (t) of the pixel on the cerebral artery and the time density of the pixel on the brain tissue (capillary blood vessel) are obtained from the obtained volume data files. A curve Ci (t) and a time density curve Csss (t) of a pixel on the cerebral vein are measured. In the CBP study, an ideal relationship established between the concentration time curve Ca (t) of the cerebral artery and the concentration time curve Ci (t) of the brain tissue is used as the analysis model. When contrast medium is injected from a blood vessel just before entering the brain tissue, the time density curve in the unit volume (1 pixel) of the brain tissue is vertical, maintains a constant value for a while, and then rises steeply. It goes down. This is approximated by a rectangular function (box-MTF method: box-Modulation Transfer Function method). That is, the transfer function between the input function and the output function is approximated by a rectangular function using the time concentration curve Ca (t) of the cerebral artery as an input function and the time concentration curve Ci (t) of the brain tissue as an output function. The transfer function represents the process by which the tracer passes through the capillaries. A rectangular transfer function MTF is calculated pixel by pixel for all pixels in the brain tissue region. From the calculated transfer function MTF, indices (CBP, CBV, MTT) representing the blood flow dynamics of the brain tissue are calculated for every pixel in the brain tissue region.

  The image rendering unit 8 includes a color information creation unit 9 that converts each function value of the three-dimensional functional map into color information based on the color table, transparency according to the pixel value for each pixel with respect to the volume data file, and the like. MPR images by volume rendering using the morphological information processing unit 10 that substantially extracts a region of interest such as a blood vessel and generates three-dimensional morphological image data and color information together with the three-dimensional morphological image Or it has the image preparation rendering part 11 which produces | generates 3D image (projection image). The color information creation unit 9 has a function of arbitrarily editing a color table that associates function information with color information in accordance with an instruction from the operator. In the MPR process, an MPR image having an arbitrary cross section is generated as a morphological image from the volume data file, and an arbitrary cross section color map related to function information is superimposed on the MPR image in a translucent manner. Volume rendering processing of the image creation / rendering unit 11 includes shadow volume rendering, shadowless volume rendering, maximum value projection volume rendering, minimum value projection volume rendering, average value projection volume rendering, and surface display rendering by specifying a threshold value. It is arbitrarily selected by the operator.

  The image display control unit 12 controls display of a display layout, display conditions, image information, and the like for display control of the three-dimensional image having color information generated by the image creation / rendering unit 11. The display unit 13 displays a signal output from the image display control unit 12. FIG. 3 shows an MPR image of the brain colored according to the blood flow. FIG. 4 shows a surface image that is partially colored according to blood flow. Here, a functional map that is obtained by quantifying and color-coding the function information created based on the function information is pasted and displayed on the surface image as the morphological image. In addition, as a display condition, color display may be limited to a part where the morphological image or the function information matches a predetermined condition, for example, a part where blood flow is less than a predetermined value and suspected ischemia.

  As described above, according to the present embodiment, when a volume data file is specified and a morphological image is generated and displayed from the file, a dynamic data file of the same subject and the same part is automatically searched and exists. If there is, functional information such as blood flow is calculated from the dynamic data file, and a morphological image is displayed automatically colored according to the functional information. An operator can specify the desired volume data file, and can receive the provision of function information without unnecessary operations.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure which shows the structure of the medical image display apparatus which concerns on embodiment of this invention. The figure which shows the operation | movement procedure by this embodiment. The halftone image which shows an example of the MPR image produced | generated by this embodiment. The halftone image which shows an example of 3D image (surface image) produced | generated by this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Volume data file storage part, 2 ... Contrast image automatic search part, 3 ... Dynamic data automatic search part, 4 ... Image data load part, 5 ... Image same position reference part, 6 ... Functional information quantification part, 7 ... Funk 8: Image rendering unit, 9 ... Color information creation unit, 10 ... Form information processing unit, 11 ... Image creation / rendering unit, 12 ... MPR unit, 13 ... 3D unit, 14 ... Image display control unit , 15 ... display section.

Claims (9)

The first volume data file collected for the brain tissue area by the X-ray computed tomography apparatus and the time collected under the blood vessel enhancement for the brain tissue area by the dynamic scan of the X-ray computed tomography apparatus Storage means for storing a continuous series of second volume data files,
A three-dimensional morphological image generator for generating three-dimensional morphological image data related to blood vessels from the first volume data file;
Means for generating a three-dimensional functional map relating to a blood flow dynamic index of the brain tissue region from the series of second volume data files;
Means for giving color information according to a value of a blood flow dynamic index at a position on the three-dimensional functional map corresponding to each pixel of the three-dimensional morphological image;
Means for generating a two-dimensional morphological image by volume rendering from the three-dimensional morphological image to which the color information is assigned ;
A medical image display device comprising: means for displaying the morphological image .   2. The medical image display apparatus according to claim 1, wherein the second volume data file is specified based on incidental information of the first volume data file.   2. The medical image display apparatus according to claim 1, further comprising means for aligning positions between the first volume data file and the second volume data file based on anatomical information.   2. The blood flow dynamic index is a blood flow volume or a blood flow passage time calculated based on a change in concentration of a contrast medium with time extracted from the second volume data file. The medical image display device described.   The medical image display apparatus according to claim 1, further comprising means for editing a correspondence between the value of the blood flow dynamic index and the color information.   The medical image display apparatus according to claim 1, wherein the color information is given only to a portion where the value of the blood flow dynamic index matches a predetermined condition. The function information is displayed only in the blood vessel region,
The medical image display apparatus according to claim 1, further comprising means for extracting a portion corresponding to a blood vessel region from the second volume data file and displaying a moving image. The three-dimensional morphological image is generated by any one of a shadow volume rendering, a shadowless volume rendering, a maximum projection volume rendering, a minimum projection volume rendering, an average projection volume rendering, and a surface display rendering by specifying a threshold value. The medical image display apparatus according to claim 1.   The medical image display apparatus according to claim 1, wherein the color information corresponding to the value of the blood flow dynamic index is given to each pixel of an image generated by the shadowed volume rendering or the shadowless volume rendering.

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