JP4322459B2 - X-ray diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray diagnostic apparatus that can easily determine suitable X-ray conditions and the like using a human body model.
[0002]
[Prior art]
An X-ray diagnostic apparatus is an image apparatus that displays the intensity of X-rays transmitted through the body of a subject as a grayscale image, and there are various apparatuses depending on purposes such as diagnosis and treatment. The means for visualizing the transmitted X-ray image can be roughly divided into two methods, imaging and fluoroscopy. For example, an X-ray diagnostic apparatus using fluoroscopy can display a collected X-ray image as a moving image on a television monitor in real time, and is excellent in immediacy. In addition, an X-ray diagnostic apparatus using imaging can provide an X-ray image captured on a film by intense X-ray irradiation with high spatial resolution and sharpness.
[0003]
The diagnosis / treatment work using this X-ray diagnostic apparatus is, for example, as follows. First, blood vessel running is performed after performing angiography with a contrast agent while seeing through the diagnostic region of the subject with an X-ray diagnostic apparatus. The surgeon advances the guide wire or cartels to the treatment site while confirming the blood vessel running, and confirms the condition of the affected area and performs treatment. When the progression of the cartels to the affected area is completed, imaging for confirming the condition of the affected area is executed, and an X-ray image is recorded on the storage medium. These operations are repeated as necessary to complete diagnosis and treatment.
[0004]
In such diagnosis and treatment work, it is necessary to appropriately perform arm movement and table movement by manual operation in order to control the observation site within the visual field. In addition, when X-rays are exposed in fluoroscopy and radiography, it is necessary to determine appropriate X-ray conditions for each diagnostic site so that halation does not occur.
[0005]
Furthermore, in the above-described diagnosis / treatment work, various analyzes such as blood vessel stenosis rate and distance measurement and cardiac ejection fraction measurement may be performed. At this time, in order to calculate the actual length on the image, calibration is performed from the catheter or calibration object shown in the image, or from the angle or magnification of the arm.
[0006]
However, it is generally difficult to predict an appropriate X-ray condition for each diagnostic site. In particular, when performing test exposure to determine accurate X-ray conditions, the patient is exposed to extra exposure. In addition, for example, in the DSA technique, it is difficult to quickly arrange the imaging system at an appropriate position, which places a great burden on the operator. Further, distance measurement from a catheter or the like shown in the image is an approximate value depending on the size of the pixel, and its accuracy is limited.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object thereof is to provide an X-ray diagnostic apparatus capable of improving X-ray diagnostic efficiency and diagnostic accuracy using a human body model.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes the following measures.
[0009]
The invention according to claim 1 is an X-ray generation unit that emits X-rays to a subject on a bed according to an X-ray condition; an X-ray detection unit that detects X-rays from the X-ray generation unit; A supporter that supports the X-ray generation means and the X-ray detection means, an X-ray absorption rate, an X-ray condition, and a halation value so that the X-ray generation means and the X-ray detection means face each other. Storage means for storing the associated table; Pre-set X-ray conditions, information on the X-ray absorption rate distribution of the subject, the table X-ray diagnosis, comprising: an estimation means for estimating a halation area, and a control means for controlling the X-ray condition of the X-ray generation means based on the estimated halation area Device.
The invention according to claim 7 is an X-ray generation means for irradiating an object on a bed according to an X-ray condition, an X-ray detection means for detecting an X-ray from the X-ray generation means, A supporter that supports the X-ray generation means and the X-ray detection means, an X-ray absorption rate, an X-ray condition, and a halation value so that the X-ray generation means and the X-ray detection means face each other. Storage means for storing the associated table; Pre-set X-ray conditions, information on the X-ray absorption rate distribution of the subject, the table An X-ray diagnostic apparatus comprising: an estimation unit that estimates a halation region, and a filter unit that suppresses X-ray exposure to the estimated halation region.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, first and second embodiments of the present invention will be described with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.
[0025]
(First embodiment)
FIG. 1 is an external view of an X-ray diagnostic apparatus 10 having a C-arm structure according to the present embodiment viewed from the head side of a subject on which a bed 21 is mounted. FIG. 2 is an external view of the C-arm structure X-ray diagnostic apparatus 10 according to the present embodiment as viewed from the side of the subject on which the bed 21 is mounted. As shown in each figure, the X-ray diagnostic apparatus 10 includes a data processing unit 11, an X-ray generation unit 12, an X-ray detector 14, a bed 21, a C arm 16, an image display monitor 54, and an operation unit 62. Yes.
[0026]
An X-ray generator 12 is provided at one end of the C-arm 16 and an X-ray detector 14 is provided at the other end. A rail is provided on the back surface or side surface of the C arm 16, and the C arm 16 is slidable along the rail.
[0027]
The X-ray generator 12 provided at one end of the C-arm 16 is an X-ray tube that emits X-rays to the subject P, and an X-ray that collimates the X-rays emitted from the X-ray tube. It has an aperture device. The X-ray tube is a vacuum tube that generates X-rays, and generates X-rays by accelerating electrons by a high voltage generated by a high voltage generator (not shown) and colliding with a target.
[0028]
The X-ray detector 14 provided at the other end of the C arm 16 is, for example, I.D. I. (Image intensifier) and an optical system. X-ray detector 14 is an I.D. I. X-ray information transmitted through the subject is converted into optical information, and this optical information is collected by an optical lens by an optical system. In addition, I.I. I. An X-ray flat panel detector is an example of the other detection device. This X-ray detector detects an X-ray signal by generating electron holes by applying X-rays transmitted through a subject to a photoelectric film, accumulating them in a semiconductor switch, and reading them out as an electrical signal. is there. In this X-ray diagnostic apparatus, any detector may be used.
[0029]
The bed 21 includes a subject P, a top plate for mounting, and a leg that supports the top plate. The top plate is movable in the vertical direction and the horizontal direction, whereby the subject P is placed at an appropriate imaging position.
[0030]
FIG. 3 is a functional block diagram of the X-ray diagnostic apparatus 10. As shown in FIG. 3, the X-ray diagnostic apparatus 10 includes an X-ray generator 12, a high voltage generator 13, an X-ray detector 14, an X-ray controller 15, a position sensor 30, a position storage medium 34, and an X-ray condition. Determination unit 36, human body model generation unit 38, X-ray absorption rate distribution data generation unit 39, CPU 40, main storage device 41, motor 42, machine control unit 44, exposure timer control unit 48, luminance control unit 50, image signal processing unit 52, an image display monitor 54, an operation unit 60, and an external communication I / F 62. Each component in the data processing unit 11 is connected by a bus and can transmit and receive various signals.
[0031]
The filter control unit 140 included in the X-ray detector 14 inserts a compensation filter for preventing halation in a predetermined region in response to a predetermined signal.
[0032]
The high voltage generator 13 is a device that boosts / rectifies the voltage supplied from the X-ray controller 15 and supplies DC power to the X-ray generator 12.
[0033]
The X-ray control unit 15 performs control related to the X-ray exposure time such as a voltage or a current supplied to the X-ray generation unit 12 based on the determined X-ray condition.
[0034]
The measuring device 17 measures the height of the subject on the bed 21, the size of a predetermined part, and the like using, for example, an optical camera or a laser. The measured information is stored in the main storage device 41 and managed for each subject (patient).
[0035]
The position sensor 30 is, for example, an optical detector, a mechanical detector provided so as to correspond to the machine control unit 44 for each moving direction, or a so-called absolute type that is a magnetic type, a brush type, a photoelectric type, or the like. An encoder or the like can be used. Further, the position sensor 30 may be either a rotary encoder or a linear encoder.
[0036]
The position storage medium 34 stores information on the position of the C arm in association with the position information obtained by the machine control unit 44.
[0037]
The halation region estimation unit 35 has a table that associates the X-ray absorption rate, the X-ray condition, and the halation value set in advance from the image level, and the X-ray absorption rate distribution obtained by the processing described later, The halation area is automatically calculated from the X-ray conditions set in the system when the linear absorptance distribution is displayed.
[0038]
The X-ray condition determining unit 36 is at least one of the X-ray tube voltage, the X-ray tube current, the imaging time (exposure time), the collimator width of the X-ray diaphragm device, etc. (Hereinafter referred to as “X-ray conditions”). In addition, the X-ray condition determining unit 36 calculates an X-ray condition in which halation does not occur from data of an X-ray absorption distribution obtained by processing to be described later, and transmits the X-ray condition to the X-ray control unit 15. .
[0039]
The human body model generation unit 38 generates a human body model related to a patient based on various images stored in the main storage device 41 and accompanying information of each image. Specifically, the human body model generation unit 38 stores the personal information of the patient (gender, age, height, weight, rough system classification, etc.) stored in the main storage device 41 or input from the operation unit 60, or Based on the actual dimensions of the main part of the patient measured by the measuring device 17, a human body model of the patient or the diagnosis target part is generated. The generated human body model may have a configuration that approximately represents a patient or the like by an ellipse or a sphere, or may have a configuration that faithfully represents a human body or the like. The generation of the human body model is described in detail in, for example, Japanese Patent Laid-Open No. 2000-152924.
[0040]
Further, the human body model generation unit 38 automatically selects a profile closest to the patient from a plurality of human body tomographic profiles stored in the main storage device 41 based on the physical information of the patient, and the selected profile Create a whole body model using. Creation of a pseudo human body model based on the human body profile and acquisition of an X-ray absorption rate distribution using the model will be described in the second embodiment.
[0041]
The X-ray absorption rate distribution data generation unit 39 calculates an X-ray absorption rate based on the human body model generated by the human body model generation unit 38 and various physical information obtained from the X-ray diagnostic apparatus. An x-ray absorption distribution for the patient is generated. Specifically, the X-ray absorption rate distribution data generation unit 39 includes the X-ray condition input from the X-ray generation unit 12 and the X-ray control unit 15 and the position of the C arm 16 obtained from the machine control unit 44, Various information obtained from the position of the bed 21 and the position of the X-ray detector 14 (SID, angle formed by the axis connecting the X-ray generator 12 and the X-ray detector 14 and the subject body axis or an arbitrary reference axis, etc. ) And the object thickness at each position obtained from the generated human body model, an absorption rate for each pixel is obtained, and an X-ray absorption rate distribution is generated.
[0042]
In addition, the X-ray absorption rate distribution data generation unit 39 generates an X-ray based on an image acquired by a modality other than the X-ray diagnostic apparatus, for example, an X-ray CT apparatus, an MRI, and various physical information from each modality. The absorption rate is calculated and an X-ray absorption rate distribution for the patient is generated. The X-ray absorption rate distribution data generation unit 39 will be described in detail later with respect to the X-ray absorption rate distribution data generation processing. The obtained X-ray absorption rate distribution is stored in the main storage device 41 in association with the position information of the C-arm 16, the position information of the bed 21, the position information of the X-ray detector 14, and the human body model. Is displayed superimposed on.
[0043]
The CPU 40 is a central processing unit that performs control related to collection of X-ray fluoroscopic image data and control related to image processing of the collected image data.
[0044]
The main storage device 41 stores X-ray images obtained by the image signal processing unit 52, CT images received via a network, MRI images, a plurality of human body tomographic profiles, and the like. Note that the human body tomographic profile stored in the main storage device 41 is a tomographic image, and a profile such as a built-in position and size at the tomographic position is also combined. The forms of the main storage device 41 and the position storage medium 34 are, for example, other IC memories such as PROM (EPROM, EEPROM, Flash, EPROM), DRAM, SRAM, SDRAM, optical disc, magnetic disc, magneto-optical disc, semiconductor storage device, etc. Can be considered.
[0045]
Based on the drive signal from the machine control unit 44, the motor 42 translates the C-arm 16 along the body axis direction or rotationally moves around the subject, and rotates around the subject P.
[0046]
The machine control unit 44 detects information on the relative position between the C arm 16 and the subject P from the drive signal transmitted to the motor 42 and the information from the position sensor 30, and transmits the information to the CPU 40.
[0047]
Further, the machine control unit 44 detects information related to the positioning of the C arm 16 from the drive signal transmitted to the motor 42 and the information from the position sensor 30, and transmits the detected information to the CPU 40. Each position information is attached to an image for each frame and is also managed as attribute information.
[0048]
The exposure timer control unit 48 converts X-rays that have passed through the subject into electrical signals, and automatically controls an exposure timer such as a photo timer that blocks the X-rays when the integrated value of the electrical signals reaches a certain value. Based on the information of the exposure timer, the film density can be kept constant by automatically controlling the photographing time, for example.
[0049]
The luminance control unit 50 receives the signal from the optical system 46, resets the X-ray condition so that the average luminance with respect to the reference region in the fluoroscopic or captured image becomes an appropriate luminance, and the X-ray control unit 15 To give feedback.
[0050]
The image signal processing unit 52 generates X-ray image data based on a signal from the X-ray detector 14, performs a predetermined process such as calibration, and performs normal X-ray diagnostic image, mask image, contrast image, A subtraction image or the like is generated. These images are stored in the main storage device 41.
[0051]
The image display monitor 54 displays the image data generated by the image signal processing unit 52.
[0052]
The operation unit 60 is an input device including a keyboard, various switches, a mouse, and the like. Specifically, an interface for inputting and setting an X-ray exposure switch, a C-arm movement direction / speed control switch, an image acquisition direction input switch, an imaging region, an X-ray exposure position interval, and the like is provided. .
[0053]
The external communication I / F 62 transmits / receives various information to / from a hospital information system that comprehensively manages various information in a hospital, an image server that accumulates images acquired by an X-ray CT apparatus or MRI, via a network. I do.
[0054]
FIG. 4 is a diagram conceptually showing the exchange between the X-ray diagnostic apparatus 10 and the hospital information system or image server by the external communication I / F 62. As shown in the figure, the external communication I / F 62 receives, for example, patient information from the hospital information system, the latest CT image and imaging condition / gantry information from the image server, or the latest MRI image and image collection gantry information. Receive. These pieces of information are stored in the main storage device 41, and are managed for each patient in association with images and imaging conditions collected by the X-ray diagnostic apparatus 10, CT images acquired in the past, MRI images, and the like.
[0055]
(X-ray absorption distribution image generation)
Next, the X-ray absorptivity distribution image generation function of the X-ray diagnostic apparatus 10 will be described. This distribution image is generated based on images acquired by various modalities using, for example, X-rays. Hereinafter, generation of the X-ray absorptivity distribution image will be described for each of the cases of using the X-ray condition of the X-ray diagnostic image and using the CT image.
[0056]
FIG. 5 is a flowchart showing a processing procedure when an X-ray absorption rate distribution image is generated using the X-ray condition of the X-ray diagnostic image. These processes are executed in the X-ray absorption rate distribution data generation unit 39 shown in FIG.
[0057]
First, the X-ray absorption rate distribution data generation unit 39 collects images related to a patient to be diagnosed, position information of the C-arm 16 at the time of imaging managed in association with the image, position information of the bed 21, X-rays The position information of the generator 12 and the basic absorption coefficient stored in advance are acquired from the main storage device 41 (step S1a).
[0058]
Next, the subject thickness relating to the predetermined visual field is calculated based on the human body model generated by the human body model generating unit 38 (step S2a), and the predetermined visual field is obtained from the subject thickness information and various information acquired in step S1. The X-ray absorptance at is calculated (step S3a). Specifically, the X-ray absorption rate is calculated from the acquired image and the X-ray condition, and the position (part) of the subject (the patient's body) is obtained in step S1. It is determined by the various information and the object thickness information. This absorption rate calculation is performed in units of pixels. In the X-ray absorption rate calculation, correction is performed in consideration of scattered radiation and the influence of the patient's body. The calculated X-ray absorption rate data is stored in the main storage device 41 and managed in association with image data, holding device position information, bed position information, generator position information, and the like.
[0059]
Next, X-ray absorption rate distribution data is generated based on the X-ray absorption rate obtained in step S3a (step S4a). The X-ray absorptance distribution data may be generated in any form. For example, the X-ray absorptance distribution data is an image showing a two-dimensional X-ray absorptance distribution (hereinafter referred to as an “X-ray absorptance distribution image”). By doing so, it can be displayed superimposed on the image collected by the X-ray diagnostic apparatus or can be displayed alone (step S5a). This X-ray absorptivity distribution image shows contours of X-ray absorptivity, dot display (where the high absorptivity part is drawn with a high density or a large number of dots), color (gray scale) And the like) can be used. In addition, when there is an X-ray absorptivity distribution image calculated at multi-directional holding device positions using the rotation angle information and image collection rate information of the C-arm 16, a suitable X is linked to the movement of the supporter. It may be configured to automatically switch to a linear absorptance distribution image.
[0060]
Further, the X-ray absorption rate distribution image is a two-dimensional or three-dimensional image constructed by using a human body model reconstructed two-dimensionally or three-dimensionally from a CT image or an MRI image, or a human body profile described in the second embodiment. An X-ray absorptivity distribution image may be superimposed on the human body model. In these cases, it is necessary to take correspondence with which position on the bed the created human body model corresponds. This is performed, for example, as follows.
[0061]
That is, a reference position is provided for each diagnosis of the CT apparatus, MRI apparatus, and X-ray diagnostic apparatus. At the time of diagnosis, the subject is placed on a bed or the like so that a predetermined part of the subject is always at the reference position in any apparatus. The CT image and MRI image acquired under such conditions are managed together with supplementary information indicating how far the slice data is collected from the reference position and stored in the main storage device 41. On the other hand, in the present X-ray diagnostic apparatus 10, the position sensor 30 can know how far the center of the detection surface of the C arm 16 or the X-ray detector 14 is located from the reference position of the bed 21. it can. Therefore, by comparing the arrangement position of the center position of the detection surface of the C arm 16 or the detector 14 with the above-mentioned supplementary information attached to the CT image or MRI image, the created human body model and the bed (or the actual subject) (Corresponding to the position of the created human body model and the bed of various modalities or the actual subject is referred to as “position matching”).
[0062]
Note that, when a human body model is constructed based on a human body profile, which is described in the second embodiment, matching between the human body model and the current visual field can be achieved by a similar method.
[0063]
In the generation of the X-ray absorption rate distribution image, the X-ray conditions stored in advance in the main storage device 41 corresponding to the X-ray diagnostic image are used. However, the present X-ray diagnostic apparatus 10 has a function of estimating an X-ray condition from an X-ray diagnosis image described in, for example, JP-A-8-66389, and the X-ray condition estimated from this image is obtained. It is also possible to generate an absorptance distribution image.
[0064]
Next, a method using a CT image will be described below as another form for obtaining the X-ray absorption rate distribution.
[0065]
FIG. 6 is a conceptual diagram for explaining a method for obtaining an X-ray absorption distribution using a CT image. FIG. 7 is a flowchart showing a processing procedure when an X-ray absorption rate distribution image is generated using a CT image. These processes are executed in the X-ray absorption rate distribution data generation unit 39 shown in FIG.
[0066]
As shown in FIG. 7, first, the X-ray absorption rate distribution data generation unit 39 receives the position information of the bed 21 of the X-ray diagnostic apparatus 10, the position information of the C arm 16, and the X-ray generation unit 12 from the main storage device 41. Position information, visual field size, magnification ratio, CT image, imaging conditions at the time of each CT image acquisition, and CT slice position information (CT apparatus bed position information) are acquired (step S1b).
[0067]
Next, based on the information acquired in step S1, the position matching process and the X-ray visual field region are calculated (step S2b), and the X-ray pass line is estimated (step S3b). The estimation of the X-ray pass line is equivalent to the estimation of the region through which the X-ray passes as shown in FIG.
[0068]
Next, as shown in FIG. 6, based on the estimated X-ray pass line, an X-ray irradiation area indicating which position the X-ray passes through is estimated and extracted for each CT image (step S4b), and extracted. The volume data is reconstructed based on the image data relating to each X-ray irradiation area (step S5b).
[0069]
Next, among the pixels of each tomographic image constituting the volume data, the CT values of the pixels on the X-ray pass line are added, and the X-ray absorption rate for each pass line is obtained from the added data (step S6b). ), An image representing a two-dimensional X-ray absorption distribution viewed from the X-ray generation unit 12 of the X-ray diagnostic apparatus 10 is generated (step S7b). The X-ray condition when the CT image is acquired is attached to the image, and the X-ray absorption rate can be calculated using the information. In addition, as shown in FIG. 7, correction is performed in consideration of the influence of scattered radiation and the patient's body before the generation of the X-ray absorption rate distribution image.
[0070]
The created two-dimensional X-ray absorption rate distribution image is displayed on the image display monitor 54 (step S8b). Regarding the display, the same form as the method for obtaining the X-ray absorption distribution using the X-ray conditions described above can be adopted. Further, when the holding device is moved, the above flow is performed, the X-ray absorption rate distribution is generated in the visual field observed at the holding device position, and the two-dimensional X-ray absorption rate distribution image is automatically switched. Is preferred.
[0071]
(Halation area estimation function / X-ray condition automatic setting function)
The present X-ray diagnostic apparatus 10 estimates the halation area based on the X-ray absorption distribution generated as described above and informs the operator, and no halation occurs based on the X-ray absorption distribution. It has a function of calculating X-ray conditions and automatically setting it in the system.
[0072]
First, the function of estimating the halation area will be described. The halation region estimation unit 35 in FIG. 3 displays the table that associates the X-ray absorption rate, the X-ray condition and the halation value, the X-ray absorption rate distribution data obtained above, and the X-ray absorption rate distribution image. By referring to the X-ray conditions that are set when the user is on, a halation region is estimated by specifying a pixel having a pixel value that is greater than or equal to the halation value. The estimated halation area can be displayed on the X-ray absorption rate distribution image or the image collected by the X-ray diagnostic apparatus.
[0073]
In addition, the position information of the boundary between the halation area and the non-halation area is obtained from the human body model, the X-ray holding device, the X-ray generator position, the detector position, the field size, and the magnification ratio, and is recorded together with the halation distribution information. May be. Further, the filter control unit 140 may automatically insert the compensation filter in the vicinity of the halation region by transmitting the estimated position information of the halation region to the filter control unit 140.
[0074]
Next, an X-ray condition automatic setting function for calculating an X-ray condition in which halation does not occur based on the X-ray absorption rate distribution and automatically setting the system will be described with reference to FIG.
[0075]
FIG. 8 is a flowchart showing the procedure of the X-ray condition automatic setting process executed by the X-ray condition determining unit 36 and the halation region estimating unit 35. In FIG. 8, the halation region estimation unit 35 first reads the X-ray absorption rate distribution and the X-ray condition from the main storage device 41 (step S1c), and estimates the halation region (step S2c).
[0076]
Next, the X-ray condition determination unit 36 performs predetermined halation correction on each pixel in the halation region estimated by the halation region estimation unit 35 (step S3c). With this halation correction, the correction limit (image level) of the X-ray condition can be set. When the X-ray condition determining unit 36 determines that the halation correction exceeds the complementary field, the CPU 40 controls the filter control unit 140 to insert a compensation filter in a region exceeding the correction limit. Further, in addition to the insertion of the compensation filter, the configuration may be such that the halation correction is performed by changing the X-ray condition or performing digital halation prevention processing on the image.
[0077]
(Application for DSA)
In the present X-ray diagnostic apparatus 10, in a DSA technique in which X-ray fluoroscopy and X-ray imaging are effectively performed using a contrast agent, it is possible to simplify and improve work using a human body model. Hereinafter, the case of the stepping DSA and rotational DSA techniques will be described as an example.
[0078]
Stepping DSA is a form of bolus chase DSA in which a contrast medium is injected into a subject so that a high-concentration mass (bolus) is injected, and a contrast image is acquired by tracking the movement of the mass within a blood vessel. is there. In the bolus chase DSA, normally, as shown in FIG. 9, the imaging system (the C arm 16 provided with the X-ray generation means 12 and the X-ray detection means) extends along the body axis direction (Z-axis direction) of the subject. Moving. In particular, DSA imaging is called stepping DSA by moving the imaging system discretely a plurality of times.
[0079]
FIGS. 10A and 10B are conceptual diagrams for explaining processing executed when setting a fluoroscopic or imaging region of the stepping DSA. As shown in FIG. 10A, the operator instructs a region of interest for which an image is to be collected with respect to the human body model displayed on the image display monitor 54. The CPU 40 determines the actual position from the instructed position, the created human body model, the position information of the C arm 16, the position information of the bed 21, the position information of the X-ray generator 12, and the position information of the X-ray detector 14. Automatically calculate the positional relationship of the device.
[0080]
Next, when the region of interest, the start position, and the end position are instructed by the operator on the displayed human body model, the CPU 40 calculates a movement amount and a step stroke so that the region of interest is in the middle of the visual field. As shown in FIG. 10B, the machine control unit 44 is controlled to move the C arm 16 or the bed 21 to set a step stroke (or photographing point), a start position, and the like. Thereafter, the stepping DSA is executed according to the set conditions.
[0081]
If the X-ray absorptivity distribution and halation distribution at each location to be stepped are obtained by the above-described method, the X-ray condition at each location is automatically calculated and set, or the compensation filter is inserted. Can also be calculated automatically.
[0082]
Next, the case of the rotational DSA technique will be described. The rotation DSA is to rotate the imaging system about the body axis of the subject as shown in FIG. 11 when acquiring the contrast image by tracking the movement of the contrast medium injected into the subject. Usually, the mask image is taken in the forward path A and the contrast image is taken in the backward path B. A DSA image related to an artery can be sufficiently obtained from the forward path A and the return path B. However, when a DSA or the like related to a vein or the like is captured, a contrast image may be captured along the forward path C.
[0083]
FIG. 12 is a conceptual diagram for explaining processing executed when setting a fluoroscopic DSA perspective or imaging region. As shown in FIG. 12, the operator designates a region of interest for which an image is to be collected for the human body model displayed on the image display monitor 54. The CPU 40 determines the actual position from the instructed position, the created human body model, the position information of the C arm 16, the position information of the bed 21, the position information of the X-ray generator 12, and the position information of the X-ray detector 14. Automatically calculate the positional relationship of the device.
[0084]
Next, when the region of interest, the start position, and the end position are instructed by the operator on the human body model displayed, the CPU 40 calculates the rotation angle and bed height so that the region of interest does not deviate from the field of view during rotation. The controller 44 is controlled to move the C arm 16 or the bed 21 to an appropriate position.
[0085]
Furthermore, if the X-ray absorptivity distribution and halation distribution at each rotation position are known in the above-described processing, the X-ray condition at each location is automatically calculated, and the compensation filter insertion position is automatically calculated. It is also possible to employ a configuration that calculates automatically. In addition, when X-ray absorptivity distribution and halation distribution data are obtained in a relatively wide range by, for example, rotational imaging, a three-dimensional distribution image of X-ray absorption or a three-dimensional distribution of halation The structure which produces an image may be sufficient.
[0086]
According to the configuration described above, the following effects can be obtained.
[0087]
From the generator position, the detector position, and the visual field size of the X-ray diagnostic apparatus 10, it is possible to associate which position on the human body model composed of CT images and MRI images and how much of the X-ray absorption rate distribution. . Therefore, the X-ray absorptivity distribution and the human body model image can be accurately superimposed and displayed by the image display means of the X-ray diagnostic apparatus. The operator can easily and quickly confirm the X-ray absorption rate of the diagnostic site from this superimposed image.
[0088]
(Second Embodiment)
Next, a second embodiment of the X-ray diagnostic apparatus 10 will be described. The X-ray diagnostic apparatus 10 according to the second embodiment improves diagnosis accuracy and efficiency by using a human tomographic profile (a model based on a tomographic image simulating a human body).
[0089]
(Creation of human body model based on human fault profile)
The X-ray diagnostic apparatus 10 can create a human body model using a human body tomographic profile. This human body model creation based on the human tomographic profile is beneficial when there is no CT image or MRI image related to the patient and a human body model cannot be created. Hereinafter, a description will be given with reference to FIG.
[0090]
FIG. 13 is a flowchart showing the procedure of the human body model creation process based on the human body tomographic profile executed by the human body model generation unit 38. In FIG. 13, first, the human body model generation unit 38 reads a plurality of human tomographic profiles and body size data from the main storage device 41 (step S1d). As the body size data used here, data measured by a method similar to Japanese Patent Laid-Open No. 2000-152924 can be used.
[0091]
Next, the human body model generation unit 38 compares the body size data with each human tomographic profile and tomographic position information, visceral position information, size, and the like attached to the profile, and a human tomographic profile suitable for the patient. Is extracted (step S2d), and the human body model of the patient is created using the human body tomographic profile (step S3d). In step S2d, a suitable human tomographic profile may be extracted with reference to a CT image or an MRI image.
[0092]
The association between the human body model and the region of interest of the X-ray image by the X-ray diagnostic apparatus is executed as follows. That is, first, the association between the human body model and the C-arm 16 position is performed by the method described above. The C-arm 16 is then moved to at least two different positions and images are collected at each location.
[0093]
Next, an observation area on each collected image is designated for the displayed image. After the two designated points are back-projected onto the detection surface of the detector 14, two lines connecting the indicated point on the detection surface and the X-ray focal point of the X-ray generator 12 are obtained as shown in FIG. . By setting the intersection of the two obtained line segments as the region of interest on the human body model, the human body model and the region of interest of the X-ray image obtained by the X-ray diagnostic apparatus can be associated with each other.
[0094]
(Measurement of distance, etc. using human body model and human body fault profile)
The X-ray diagnostic apparatus 10 can obtain a distance to a target site using a human body model and a human body tomographic profile, and can calculate an exposure dose for each site with high accuracy. In addition, quantitative analysis using a human body model and a human body fault profile is also possible. Hereinafter, these contents will be described.
[0095]
First, for example, the human body model generation unit 38 generates a three-dimensional human body model by the method described above. Next, the human body model generation unit 38 corrects the human body model based on the most preferable one among the plurality of human body tomographic profiles stored in the main storage device 41. With this corrected human body model, an accurate distance from the X-ray tube to the target site can be obtained as shown in FIG. The exposure dose for each part can be measured from the distance from the X-ray tube to the target part and the instruction value of the dosimeter provided in the X-ray tube.
[0096]
In addition, accurate quantitative analysis of blood vessels and the like is possible using the corrected human body model. That is, conventionally, quantitative analysis of a diagnosis target part is generally performed based on the thickness of the catheter. In addition, since the positional relationship between the diagnosis target region and the X-ray tube changes during diagnosis, accurate quantitative analysis cannot be performed.
[0097]
On the other hand, according to the X-ray diagnostic apparatus 10, even when the C-arm 16 or the like moves, the corrected human body model considering a suitable profile as shown in FIG. The position, the distance from the X-ray tube of the site to be diagnosed, and the actual length (m / pixel) on the detection surface of the detector 14 of the site to be diagnosed can be accurately obtained. The actual length and the like of the diagnosis target part obtained in this way can be used as calibration data at the time of analysis and the like, and a highly accurate quantitative analysis can be realized.
[0098]
According to the configuration described above, the following effects can be obtained.
[0099]
According to the X-ray diagnostic apparatus 10, the X-ray absorption rate distribution and the halation distribution can be acquired based on the human body model and the X-ray condition or CT image of the X-ray diagnostic image acquired in advance. Therefore, dose management and setting of X-ray conditions can be easily performed without requiring test exposure or the like for determining X-ray conditions. As a result, it is possible to improve the diagnostic efficiency and prevent an excessive exposure to the patient. In particular, by automatically setting the X-ray conditions based on the obtained X-ray absorptivity distribution and automatically setting the compensation filter based on the halation distribution, an image can be acquired under the optimum X-ray conditions without performing complicated operations. Can do.
[0100]
Further, in the present X-ray diagnostic apparatus 10, since the created human body model is adjusted by suitable profile data, the patient data such as the size of the diagnostic part, the distance from the X-ray tube to the diagnostic part, etc. are highly accurate. It is possible to obtain. As a result, X-ray absorption rate distribution calculation, halation distribution calculation, quantitative analysis, and the like can be executed with high accuracy.
[0101]
In addition, according to the X-ray diagnostic apparatus 10, manual setting operation before imaging can be simplified by setting a stroke width or the like with a human body model in the DSA technique. Therefore, it is possible to improve the diagnostic efficiency and reduce pain for the operator and the patient.
[0102]
Although the present invention has been described based on the embodiments, those skilled in the art can come up with various changes and modifications within the scope of the idea of the present invention. It is understood that it belongs to the scope of the present invention. Further, the embodiments may be combined as appropriate as possible, and in that case, the combined effect can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention If at least one of the following is obtained, a configuration in which this configuration requirement is deleted can be extracted as an invention.
[0103]
【The invention's effect】
As described above, according to the present invention, it is possible to realize an X-ray diagnostic apparatus that can improve X-ray diagnostic efficiency and diagnostic accuracy using a human body model.
[Brief description of the drawings]
FIG. 1 is an external view of a C-arm structure X-ray diagnostic apparatus 10 according to the present embodiment as viewed from the head side of a subject mounted on a bed 21. FIG.
FIG. 2 is an external view of a C-arm structure X-ray diagnostic apparatus 10 according to the present embodiment as viewed from the side of a subject on which a bed 21 is mounted.
FIG. 3 is a functional block diagram of the X-ray diagnostic apparatus 10;
FIG. 4 is a diagram conceptually showing an exchange between the X-ray diagnostic apparatus 10 and a hospital information system or an image server by an external communication I / F 62.
FIG. 5 is a flowchart showing a processing procedure when an X-ray absorption rate distribution image is generated using an X-ray diagnostic image.
FIG. 6 is a conceptual diagram for explaining a method of obtaining an X-ray absorption rate distribution using a CT image.
FIG. 7 is a flowchart showing a processing procedure when an X-ray absorption distribution image is generated using a CT image.
FIG. 8 is a flowchart showing a procedure of an X-ray condition automatic setting process executed by the X-ray condition determining unit 36 and the halation region estimating unit 35;
FIG. 9 is a diagram for explaining a DSA technique.
FIGS. 10A and 10B are conceptual diagrams for explaining processing executed when setting a fluoroscopy or imaging region of a stepping DSA.
FIG. 11 is a diagram for explaining a DSA technique.
FIG. 12 is a conceptual diagram for explaining processing executed when setting a fluoroscopic DSA fluoroscopy or imaging region;
FIG. 13 is a flowchart illustrating a procedure of a human body model creation process based on a human body tomographic profile executed by a human body model generation unit 38;
FIG. 14 is a diagram for explaining the association between the human body model and the region of interest of the X-ray diagnostic apparatus 10;
FIG. 15 is a diagram for explaining distance measurement to a target site using a human body model and a human body tomographic profile;
FIG. 16 is a diagram for explaining quantitative analysis using a human body model and a human body tomographic profile;
[Explanation of symbols]
10 ... X-ray diagnostic equipment
11: Data processing unit
12 ... X-ray generator
13 ... High voltage generator
14 ... X-ray detector
15 ... X-ray controller
16 ... C-arm
17 ... Measuring instrument
21 ... Sleeper
30 ... Position sensor
34 ... Position storage medium
35 ... Halation region estimation unit
36 ... X-ray condition determination unit
38 ... Human body model generator
39 ... X-ray absorption rate distribution data generation unit
40 ... CPU
41. Main memory device
42 ... Motor
44. Machine control unit
46: Optical system
48 ... Exposure timer controller
50. Brightness control unit
52. Image signal processing section
54. Image display monitor
60 ... operation unit
62. Operation unit
140: Filter control unit

Claims (10)

X-ray generating means for exposing the subject on the bed to X-rays according to the X-ray conditions;
X-ray detection means for detecting X-rays from the X-ray generation means;
A supporter that supports the X-ray generation means and the X-ray detection means so that the X-ray generation means and the X-ray detection means face each other;
Storage means for storing a table in which X-ray absorption rates, X-ray conditions, and halation values are associated with each other;
Estimating means for estimating a halation area using preset X-ray conditions, information on the X-ray absorption distribution of the subject, and the table ;
Control means for controlling the X-ray condition of the X-ray generation means based on the estimated halation region;
An X-ray diagnostic apparatus comprising: The information on the X-ray absorption rate distribution of the subject is generated based on an image acquired by an X-ray diagnostic apparatus or an X-ray computed tomography apparatus. X-ray diagnostic equipment.   The table is generated by selecting a predetermined human tomographic profile from a plurality of human tomographic profiles based on information on the subject and generating the table based on the predetermined human tomographic profile. The X-ray diagnostic apparatus according to any one of 1 to 3.   The X-ray diagnostic apparatus according to claim 1, further comprising display means for displaying the halation distribution superimposed on an image indicating the X-ray absorption rate of the subject.   The X-ray diagnostic apparatus according to claim 1, further comprising a filter for suppressing X-ray exposure to the estimated halation region. X-ray generating means for exposing the subject on the bed to X-rays according to the X-ray conditions;
X-ray detection means for detecting X-rays from the X-ray generation means;
A supporter that supports the X-ray generation means and the X-ray detection means so that the X-ray generation means and the X-ray detection means face each other;
Storage means for storing a table in which X-ray absorption rates, X-ray conditions, and halation values are associated with each other;
Estimating means for estimating a halation area using preset X-ray conditions, information on the X-ray absorption distribution of the subject, and the table ;
Filter means for suppressing X-ray exposure to the estimated halation region;
An X-ray diagnostic apparatus comprising: 7. The X-ray according to claim 6, wherein the information on the X-ray absorption rate distribution of the subject is generated based on an image acquired by an X-ray diagnostic apparatus or an X-ray computed tomography apparatus. Diagnostic device. The table is a table generated by selecting a predetermined human tomographic profile from a plurality of human tomographic profiles based on information on the subject and generating the table based on the predetermined human tomographic profile. The X-ray diagnostic apparatus according to 6 or 7 . The X-ray diagnostic apparatus according to claim 6 , further comprising display means for displaying the halation distribution superimposed on an image indicating the X-ray absorption rate of the subject. 10. The X-ray diagnosis according to claim 6 , further comprising a control unit that controls the X-ray condition of the X-ray generation unit based on the estimated halation region. 10. apparatus.

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