CN1927123A

CN1927123A - X-ray computed tomography apparatus

Info

Publication number: CN1927123A
Application number: CNA2006101513698A
Authority: CN
Inventors: 长田清; 津雪昌快
Original assignee: Toshiba Corp; Toshiba Medical Systems Corp
Current assignee: Canon Medical Systems Corp
Priority date: 2005-09-07
Filing date: 2006-09-07
Publication date: 2007-03-14
Anticipated expiration: 2026-09-07
Also published as: CN100518652C

Abstract

An X-ray computed tomography apparatus includes an X-ray source (101) which generates X-rays, a high voltage generating unit (104) which generates a high voltage to be applied to the X-ray source, an X-ray detector (102) which detects X-rays transmitted through a subject to be examined to generate projection data, a storage unit (203) which stores the projection data in association with electrocardiographic data of the subject, a setting unit (207) which sets a specific cardiac phase in accordance with an operator's instruction, a reconstruction unit (206) which reconstructs a tomogram on the basis of a plurality of projection data sets acquired in a plurality of specific periods centered on the specific cardiac phase throughout a plurality of cardiac cycles, a period extending unit (207) which extends the specific period on the basis of a heart rate fluctuation range of the subject, and a control unit (212) which controls the high voltage generating unit to generate a relatively high dose of X-rays in the extended specific period and generate a relatively low dose of X-rays in a period other than the extended specific period.

Description

The X ray computer laminagraph device

The cross reference of related application

The application based on and advocate the priority of the No.2005-285863 that No.2005-259614 of Japanese patent application formerly that JIUYUE in 2005 was submitted on the 7th and JIUYUE in 2005 were submitted on the 30th, its full content is by reference in conjunction with in this application.

Technical field

The present invention relates to a kind of electrocardio that can carry out and rebuild (ECG gated reconstruction: X ray computer laminagraph device ECGgated reconstruction) synchronously.

Background technology

The X ray computer laminagraph device is according to the intensity of the X ray that sees through subject, utilizes image that information about subject is provided, and plays an important role in the multiple medical act that with medical diagnosis on disease, treatment and surgical planning etc. is representative.

In the fast cardiac work up of motion, carry out electrocardio synchronous scanning.So-called electrocardio synchronous scanning is to collect electrocardiogram synchronizing signal (triggering signal, R ripple signal) and electrocardiographic wave signal (ECG signal) etc. concurrently with scanning, behind data collection, uses the electrocardiographic wave signal, obtains and the heartbeat phase synchronized images.

Recently, in cardiac work up, attempt exposing to the sun and penetrating the minimizing that realizes being exposed to the sun and penetrate by utilizing ecg information only particular phases to be carried out X ray.

But, the spy open in the 2000-342577 communique not shown how to determine X ray expose to the sun penetrate during.In addition, open in the 2000-51208 communique, use the R-R wave spacing (heart beat cycle) between 1 heart beat period before scanning, collecting, during the X ray when determining scanning exposes to the sun and penetrates the spy.This is perhaps applicable to the constant heart anthropometric dummy of heart beat cycle.But the heart beat cycle of actual subject (patient) is unsettled, even before scanning, the heart beat cycle between heart beat period neither be constant several times, only adopts 1 heart beat cycle between heart beat period to determine that it is unpractical that X ray exposes to the sun during penetrating.In addition, in the cardiac work up that carried out between several seconds～tens seconds, a plurality of heart beat cycles during scanning are not identical with scanning 1 preceding heart beat cycle.Therefore, may not expose to the sun in the phase place that the operator wants to rebuild and penetrate X ray (not obtaining data), but collected the data during useless on the contrary.

In addition, as mentioned above, the X ray computer laminagraph device is according to the intensity of the X ray that sees through subject, utilizes image that information about subject is provided, and plays an important role in the multiple medical act headed by medical diagnosis on disease, treatment and the surgical planning etc.Especially in using the cardiac work up X ray computer laminagraph device, that motion is fast, the temporal resolution that improves image is an important topic.Direct processing method to this problem is to shorten the time of the each rotation of X-ray tube, promptly realizes the high speed of scanning.By the high speed of this scanning, and electrocardiogram synchronously scans, the so-called electrocardio synchronous scanning method of only collecting the data between the given period in the heart beat cycle plays a role effectively.Produce X ray in being defined between given period, or the intensity of X ray is modulated it with uprising.Thus, compare with shining X ray continuously, realizing is exposed to the sun penetrates the reduction of quantity of X-rays X.

But, owing to reasons such as arrhythmias, the required data for projection of image reconstruction of desired heart time phase place takes place not collect sometimes, perhaps not with the situation of high SN than the collection data for projection.In this case, the image quality aggravation of reconstructed image.According to circumstances, must rescan sometimes.And, less than the technology of before reconstruction, confirming above-mentioned situation.

Summary of the invention

The objective of the invention is to, in the X ray computer laminagraph device that can carry out electrocardio reconstruction synchronously, prevent that the part of the data for projection that image reconstruction is required from losing.

According to a first aspect of the invention, provide a kind of X ray computer laminagraph device, it is characterized in that possessing: x-ray source produces X ray; X-ray detector in order to produce data for projection, detects through the X ray behind the subject; Storage part associates storage with the ECG data of described data for projection and described subject; Specific heartbeat phase is set according to operator's instruction in the configuration part; Reconstruction portion is come reconstructed image according to a plurality of projected datasets of collecting in striding between a plurality of given periods of a plurality of heart beat cycles; Determination portion according to the specific heartbeat phase and the heart rate mobility scale of described subject, is determined to scan between the first phase of described subject with high X ray amount; And control part, control the tube current of described x-ray source, so that produce X ray with higher quantity of X-rays X between the described first phase, give birth to X ray or stop to produce X ray with low ray volume production in the second phase beyond between the described first phase.

According to a second aspect of the invention, provide a kind of X ray computer laminagraph device, it is characterized in that possessing: storage part, the ecg information that storage is collected from subject; The heartbeat phase that will rebuild of described subject is set in the configuration part; X-ray source exposes to the sun to subject and to penetrate X ray; The high voltage generating unit applies high voltage to described x-ray source; X-ray detector detects through the X ray behind the described subject; Reconstruction portion according to by the detected data for projection of described detector, is rebuild the image of the heartbeat phase of being set by described configuration part; And control part, control the tube current of described x-ray source, so that with the heartbeat phase scope of high X ray amount scanning by the setting of described configuration part, and in following ranges with low X ray amount scanning or stop to produce X ray: this scope be by response as trigger and with the parallel electrocardiogram that obtains of scanning, from ecg cycle, obtain after the described heart beat cycle scope of eliminating.

According to a third aspect of the invention we, a kind of X ray computer laminagraph device is provided, it is characterized in that possessing: be used to scan the pallet of subject, have the X-ray detector that exposes to the sun the x-ray source of penetrating X ray and detect the X ray after seeing through described subject to subject; Storage part, the electrocardiogram that storage is collected from subject; The configuration part, the heartbeat phase scope of the layer image of described subject is rebuild in setting; Reconstruction portion according to the detected data for projection of described detector, is rebuild the layer image of the particular phases in the heartbeat phase scope of being set by described configuration part; And control part, control the tube current of described x-ray source, so that will with the parallel electrocardiogram of obtaining of described scanning as triggering, the heartbeat phase scope of setting by described configuration part with high X-ray scanning, and scan with low X ray amount and to remove the scope after the described heartbeat phase scope in the described cardiac electrical cycle or to stop to produce X ray.

According to a forth aspect of the invention, provide a kind of X ray computer laminagraph device, it is characterized in that possessing: scanner section, on one side the modulation of X-ray amount carry out helical scanning on one side; Reconstruction portion, parallel with described helical scanning, according to data for projection, utilize fladellum to rebuild and rebuild layer image in rapid succession, and after described helical scanning finishes,, utilize cone beam to rebuild reconstructed image according to data for projection; And display part, show with described helical scanning to walk abreast, utilize described fladellum to rebuild the layer image of rebuilding in rapid succession, and after described helical scanning finishes, show and utilize described cone beam to rebuild the image of being rebuild.

According to a fifth aspect of the invention, a kind of X ray computer laminagraph device is provided, it is characterized in that possessing: be used to scan the scanner section of subject, have the X-ray detector that exposes to the sun the x-ray source of penetrating X ray and detect the X ray after seeing through described subject to subject; Storage part, the electrocardiogram that storage and described scanning are collected from subject concurrently; The heartbeat phase of the image want to rebuild described subject is set in the configuration part; Reconstruction portion according to by the detected data for projection of described detector, is rebuild the image of the heartbeat phase of being set by described configuration part; And control part, control the tube current of described x-ray source, so that according to the electrocardiogram of collecting concurrently with described scanning, in the prescribed limit that comprises the heartbeat phase of setting by described configuration part, improve the X ray amount, and in removing the scope of this prescribed limit, reduce the X ray amount or stop to produce X ray.

According to a sixth aspect of the invention, a kind of X ray computer laminagraph device is provided, it is characterized in that possessing: be used to scan the scanner section of subject, have the X-ray detector that exposes to the sun the x-ray source of penetrating X ray and detect the X ray after seeing through described subject to subject; Storage part, the ECG information that is stored in before the described scanning and collects from subject concurrently with described scanning; The heartbeat phase of the image want to rebuild described subject is set in the configuration part; Reconstruction portion according to by the detected data for projection of described detector, is rebuild the image of the heartbeat phase of being set by described configuration part; And control part, control the tube current of described x-ray source, so that will be stored in the described storage part, with the parallel ECG information that obtains of described scanning as triggering, improving the X ray amount according to being stored in a plurality of hearts rate in the described storage part, that before described scanning, collect in definite prescribed limit, and in removing the scope of this prescribed limit, reducing the X ray amount or stop to produce X ray.

According to a seventh aspect of the invention, provide a kind of X ray computer laminagraph device, it is characterized in that possessing x-ray source, produce X ray; X-ray detector in order to produce data for projection, detects through the X ray behind the subject; Storage part associates storage with the ECG data of described data for projection and described subject; The addition handling part is between a plurality of projected datasets of collecting in striding between a plurality of given periods a plurality of heart beat cycles, that with specific heartbeat phase be the center, the identical data for projection weighting summation in visual angle; And reconstruction portion, according to a plurality of projected datasets behind the described weighting summation, reconstructed image.

According to an eighth aspect of the invention, provide a kind of X ray computer laminagraph device, it is characterized in that possessing: x-ray source produces X ray; X-ray detector in order to produce data for projection, detects through the X ray behind the subject; Configuration part between given period according to operator's indication, is set between given period in the heart beat cycle of described subject; Reconstruction portion is according to the data for projection of collecting between described given period, reconstructed image; Extension process portion, according to the corresponding time width of angular range of the required data for projection of image reconstruction, expand between described given period; And control part, according between the given period after the described expansion, control is from the generation of the X ray of described X-ray tube/stop or intensity modulated.

According to a ninth aspect of the invention, provide a kind of X ray computer laminagraph device, it is characterized in that possessing: x-ray source produces X ray; X-ray detector in order to produce data for projection, detects through the X ray behind the subject; Storage part associates storage with the ECG data of described data for projection and described subject; Specific heartbeat phase is set according to operator's instruction in the configuration part; Reconstruction portion is come reconstructed image according to a plurality of projected datasets of collecting in striding between a plurality of given periods of a plurality of heart beat cycles, corresponding with described specific heartbeat phase between wherein said given period; The extension according to the heart rate mobility scale of described subject, is expanded between each described given period during this time; And control part, control the tube current of described x-ray source so that produce X ray with higher quantity of X-rays X, and beyond between the given period after described expansion during in the living X ray of low ray volume production or stop to produce X ray.

Other purpose of the present invention and advantage will be illustrated by following description, and a part is conspicuous from this description, maybe can obtain by the practice invention.Can realize and obtain objects and advantages of the present invention by means and the combination of specifically noting below.

Description of drawings

The accompanying drawing of an introducing and a formation description part illustrates the present illustrated embodiments of the present invention, and with the above-mentioned generality description and the detailed description of following most preferred embodiment, explains the principle of invention.

Fig. 1 is the figure of structure of the X ray computer laminagraph device of expression embodiment of the present invention 1.

Fig. 2 A is the figure that is illustrated in the time variation of heart rate when practising in the embodiment 1.

Fig. 2 B is the figure that is illustrated in the time variation of heart rate when scanning in the embodiment 1.

The figure of the position of the heartbeat phase that Fig. 2 C maximum heart rate on to be expression with time of the heart rate of Fig. 2 B change, during exercise is a benchmark.

The figure of the position of the heartbeat phase that Fig. 2 D minimum heart rate on to be expression with time of the heart rate of Fig. 2 B change, during exercise is a benchmark.

Fig. 2 E is the figure during the high X ray in the expression present embodiment.

Fig. 3 A is the figure of expression from the mobility scale of the manual heart rate of setting of Fig. 1 operating portion.

Fig. 3 B is the mobility scale figure of expression by the heart rate of the systems control division automatic setting of Fig. 1.

Fig. 4 is the eclipsed figure of expression by the segmentation (segment) of the reconstruction process portion generation of Fig. 1.

Fig. 5 is the figure of structure of the X ray computer laminagraph device of expression embodiment of the present invention.

Fig. 6 is the skeleton diagram of the X-ray tube of Fig. 1.

Fig. 7 is the flow chart of the processing procedure of expression scanning of present embodiment and pre-process and post-process thereof.

Fig. 8 is the supplementary notes figure of Fig. 7.

Fig. 9 is the figure that expression utilizes the picture example in the scanning that the X ray output control specialist system of Fig. 5 carries out.

Figure 10 is illustrated among the S22 of Fig. 7, the figure that X ray modulation control stopped to move when the heart rate difference surpassed upper limit heart rate difference.

Figure 11 is that expression utilizes the affirmation picture instance graph after the S24 end of scan of specialist system is controlled in the X ray output of Fig. 5.

The specific embodiment

(embodiment 1)

Below, with reference to the embodiment 1 of description of drawings X ray computer laminagraph device of the present invention.The X ray computer laminagraph device comprises: X-ray tube and X-ray detector be rotation/rotation (ROTATE/ROTATE) type of rotation around subject integratedly; A plurality of detecting elements are arranged in ring-type or plane, the fixing/all kinds such as rotation (STATIONARY/ROTATE) type of X-ray tube rotation around the subject only, all applicable the present invention of any one type.Here, as the rotation that accounts for main flow now/rotary-type describing.In addition,, need to spend big or small data for projection (reconstruction method entirely) 1 week about 360 around the subject in order to rebuild the layer image data of 1 layer (slice), and, even half reconstruction method also needs 180 degree+α (α: Da Xiao data for projection segment angle).In the present embodiment, adopt effective half reconstruction method of photography to the fast heart that moves etc.

In addition, as the mechanism that incident X-rays is transformed into electric charge, main flow is to convert X-rays into light and then with components of photo-electric conversion such as photodiodes this light is transformed into the indirect conversion shape of electric charge with fluorophor such as flashers, and utilizes by X ray and generate the electron hole pair in the quasiconductor and the Direct Transform shape of the photoconduction electrical phenomena that moves to its electrode.As x-ray detection device, can adopt any one mode among both, but here, describe as the former indirect conversion shape.In addition, no matter be X ray computer laminagraph device, or the multitube ball-type X ray computer laminagraph device of a pipe ball-type, all applicable the present invention.Here, describe as a pipe ball-type.

Fig. 1 represents the schematic configuration of the X ray computer laminagraph device of present embodiment.This X ray computer laminagraph device possesses: be used for collecting the pallet device (scanner section) 1 about the data for projection of subject (patient) P; Be used to place the bed apparatus 3 of subject P; With control station 2, control pallet device 1 and bed apparatus 3, and according to the data of collecting by pallet device 1, carries out image reconstruction process and pictorial display etc.

The framework that pallet device 1 possesses X-ray tube 101, X-ray detector 102, runing rest 103, device for generating high voltage 104, pallet driving device 105 and accommodates transacter 107.Framework has the diagnosis peristome that is used to insert subject P.X-ray tube 101 and X-ray detector 102 are installed on the cyclic runing rest 103 that is driven by 105 rotations of pallet driving device.Here, the rotating shaft with runing rest 103 is defined as the Z axle.Be in the rotating coordinate system at center with the Z axle, will from the focus of X-ray tube 101 connect X-ray detector 102 the detection faces center, be defined as X-axis with the orthogonal axle of Z axle.Y-axis and Z axle and X-axis be quadrature all.

Runing rest 103 is under the control of scan control section 201, by 105 rotations of pallet driving device.Follow the rotation of this runing rest 103, X-ray tube 101 and X-ray detector 102 be rotation around subject P.Under the control of scan control section 201 from device for generating high voltage 104 when X-ray tube 101 applies high voltage, produce X ray from X-ray tube 101.Produce and detect by X-ray detector 102 from X-ray tube 101, and be collected in the transacter 107 as data for projection through the X ray behind the subject.The bed board 302 of bed apparatus 3 is moved by bed driving device 301.Moving of the rotation of scan control section 201 control runing rests 103 and bed board 302.By this control, can in the constant speed rotary course of runing rest 103, synchronously carry out moving continuously of bed board 302.Thus, can realize that X-ray tube 101 (x-ray source) is with respect to subject P helically moves, data for projection are collected in a plurality of positions on its helical orbit so-called helical scanning.

In the present embodiment, as an example, the situation of handling the data for projection that the multichannel helical scanning collect simultaneously by the multiple row detector obtains is described, but present embodiment also goes for collecting continuously the so-called dynamic scan of data for projection under bed board 302 immobilized states, also applicable to conventional sweep, promptly under the immobilized state in certain position, collect and rotate 1 time data for projection at bed board 302, then after bed board 302 stops to move, in the action of the data for projection of the next position repeated collection rotation 1 time.

Runing rest 103 similarly has peristome at central part with framework.During scanning, in this peristome, insert the subject P of mounting on the bed board 302 of bed apparatus 3.Electrocardiogrph 106 is used for detecting the weak current that produces from the heart of subject P from being installed in the electrode detection electrocardiosignal on the subject P, exports detected electric current over time as electrocardiogram.In addition, as described later, in the present embodiment, in systems control division 212 according to the ECG information of utilizing electrocardiogrph 106 to obtain (P ripple, Q ripple, R ripple, S ripple, T ripple, in the present embodiment for the R ripple) obtain heart rate, but also can collect ecg information, in systems control division 212, ask electrocardiogram and heart rate with electrocardiogrph 106.In addition, in Fig. 1, electrocardiogrph 106 is expressed as the part of pallet device 1, but also can constitute independently, collect from the function of the ECG information of electrocardiogrph 106 or electrocardiosignal, can in storage parts such as data for projection storage part 203, store the function of electrocardiosignal as long as possess with pallet device 1.

To between the K-A of X-ray tube 101, apply tube voltage from device for generating high voltage 104, and provide heater current (tube current) to the filament of X-ray tube 101 from device for generating high voltage 104.By applying tube voltage and heater current being provided, from the plate target generation X ray of X-ray tube 101.

X-ray detector 102 is used to detect the X ray through behind the subject P.X-ray detector 102 can be any one in multi-layered type (multiple row type), the single-layer type (string type), but here, is penetrated the minimizing effect multi-layered type detector bigger than X ray modulation function described later as exposing to the sun and describe.X-ray detector 102 is provided with the detecting element of a plurality of detection X ray respectively along the layer direction (Z-direction) of channel direction (being similar to Y direction) and subject.For example, a plurality of x-ray detection devices are arranged side by side for example about 600～1000 along channel direction, and edgewise is arranged side by side 24 row～256 row etc.In the present embodiment, a plurality of x-ray detection devices that constitute the square sensitive surface with 0.5mm * 0.5mm are arranged the 64 multiple row detectors that are listed as along 1000 of channel direction arrangements, edgewise.Each detecting element has flasher and photodiode chip (not shown).X-ray detector 102 both had been arranged with the multi-layered type detector of the detecting element of uniform-dimension applicable to edgewise, also be arranged with the multi-layered type detector of the inhomogeneous spacing of the different detecting element of a plurality of sizes applicable to edgewise.

Transacter (DAS (data acquisition system)) 107 is transformed into voltage signal with the signal that detector 102 outputs to each passage, amplifies and is transformed into digital signal.These data (being also referred to as pure initial data) are provided for the control station 2 of pallet device 1 outside.The data (pure initial data) of 202 pairs of data gathering-devices of the pretreatment portion of control station 2,107 outputs are implemented offset correction, N Reference Alignment, sensitivity correction etc. and are proofreaied and correct processing.Pretreated pure initial data is commonly referred to initial data.Here, pure initial data and initial data are generically and collectively referred to as " data for projection ".

Data for projection is associated visual angle (VIEW), the expression channel number of the anglec of rotation of the X-ray tube 101 of expression during data collection, each code of row number (according to circumstances being the position of bed board 302), is stored in the data for projection storage part 203 of control station 2 with the ECG data (electrocardiosignal) of electrocardiogrph 106.Make data for projection be associated with electrocardiosignal (or ECG information) (those skilled in the art be also referred to as set up synchronously).Data for projection and electrocardiosignal can be physically or individually are stored among of medium more than 1 or 2, also can have data for projection, electrocardiosignal memory area separately in 1 medium.

Except above-mentioned pretreatment portion 202 and data for projection storage part 203, control station 2 also has scan control section 201, image reconstruction process portion 206, inspection program configuration part 207, image storage part 209, display part 210, systems control division 212.

Image reconstruction process portion 206 carries out electrocardio and rebuilds synchronously according to being stored in ECG signal in the storage part 203 (or heart rate of being obtained by systems control division 212), data for projection.Image reconstruction process portion 206 possesses half reconstruction function, the segment reconstruction function is rebuild synchronously as electrocardio.

In half rebuilds, need X-ray tube to cover the data for projection group of 180 degree+α (α is the segment angle of fan-shaped X ray).In the segment reconstruction method, the data for projection group is made of a plurality of projected datasets (being also referred to as a plurality of segmentations).A plurality of projected datasets correspond respectively to a plurality of heart beat cycles.A plurality of projected datasets are respectively in the set of the data for projection that is the center with inspection program configuration part 207 specified specific heartbeat phase (reconstructed center phase place), collects in having between the given period of stipulated time width.

For example, under the situation of " the specific heartbeat phase of expectation: 65% ", " segment reconstruction ", " segments (projected dataset number): 3 ", the heartbeat phase that is chosen in from 3 successive or discrete heart beat cycles with 65% is 3 projected datasets collecting in the specified time limit at center.3 projected datasets cover 180 degree+segment angles.

Such as illustrated in Figure 4, between 3 projected datasets (segmentation) A, B, C, produce when overlapping, when promptly between a plurality of segmentations, having the data for projection of same view angle (angle of X-ray tube), image reconstruction process portion 206 is not a data for projection of selecting any one party at each visual angle, but makes a sectional data for projection and another sectional data for projection weighting summation at each visual angle.Relatively determine weights corresponding to heart rate.Heart rate is low more, and weights are high more, and heart rate is high more, and weights are low more.That is, long more between heart beat period, weights are high more, and short more between heart beat period, weights are low more.Can obtain the effect that reduces motion artifacts thus.For example, determine weights by following formula.According to heart rate HRA when the data collection of segmentation A and the heart rate HRB with the data collection of the partly overlapping segmentation B of segmentation A the time, the weights WA of the data for projection of segmentation A is:

WA＝((HRA+HRB)-HRA)/(HRA+HRB)＝HRB/(HRA+HRB)

The weights WB of the data for projection of segmentation B is as follows:

WB＝((HRA+HRB)-HRB)/(HRA+HRB)＝HRA/(HRA+HRB)

For example, the heart rate when collecting segmentation A is 90bps, when the heart rate when collecting segmentation B is 75bps, and the weights WA of the data for projection of segmentation A is set at 0.45, and the weights WB of the data for projection of segmentation B is set at 0.55.

Weights are not limited to corresponding with heart rate.For example, (the shared separately ratio of 180 degree+α), projected dataset is corresponding to make weights and the angular range required with respect to image reconstruction.The weight setting of the data for projection in the higher projected dataset of the ratio that is applicable to must be than the weights height of the data for projection in the lower projected dataset of the ratio that is applicable to.For example, the heart rate when collecting segmentation A is 90bps, when the heart rate when collecting segmentation B is 75bps, and the weights WA of the data for projection of segmentation A is set at 0.3, and the weights WB of the data for projection of segmentation B is set at 0.7.

In the present embodiment, the segments of segment reconstruction can be set by inspection program configuration part 207, but is made as according to the average heart rate of obtaining from electrocardiogrph 106 (or storage part 203) or waits automatically definite by average heart rate and scanning speed (rotary speed of runing rest 103) that systems control division 212 is obtained.

Image reconstruction process portion 206 is according to selected or collected projected dataset reconstructed image.Image reconstruction process portion 206 can possess fladellum reconstruction process function or cone beam reconstruction process function one of them, but in the present embodiment, possess fladellum reconstruction process function and cone beam reconstruction process function the two, in the reconstruction process function that use is set by inspection program configuration part 207 at least one rebuild images such as layer image.

And, in the present embodiment, when having set the cone beam reconstruction process by inspection program configuration part 207, image reconstruction process portion 206 is parallel with helical scanning, uses fladellum to rebuild, regardless of (not being 65% in above-mentioned example by inspection program configuration part 207 heartbeat phase specified, that will rebuild, also comprise other phase places, i.e. 0～100% data for projection), all according to the data for projection of collecting, connect and constantly rebuild layer image.

Then, image reconstruction process portion 206 finishes the back or on the backstage in helical scanning, and the data for projection according to selecting for the layer image of the heartbeat phase of rebuilding above-mentioned reconstructed object utilizes cone beam to rebuild layer image (or 3 d image).Thus, display part 210 can be followed the tracks of helical scanning, almost shows layer image in real time, after helical scanning finishes, can show the image tighter than the layer image of real-time demonstration.

In the present embodiment, as described later, change (modulation) X ray amount in scanning process, but the operator is difficult in practice judge whether the X ray amount is changed in the scanning.In the present embodiment, owing to using the few fladellum of amount of calculation to rebuild, concurrently data for projection being carried out reconstruction process with scanning, so can almost rebuild layer image in real time.The image SD of layer image changes along with the modulation of X ray amount.Because the operator is the X ray technician normally, so can discern the modulation of X ray amount according to the variation of the image SD of the layer image of demonstration in real time.In addition, though by on display part 210, show behind the end of scan amount of calculation mostly for correct layer image, by the layer image that the cone beam reconstruction obtains, can utilize the layer image more more accurate to diagnose than fladellum reconstruction method.

The data for projection that carries out the object of fladellum reconstruction with scanning concurrently can be the data for projection of being collected by inspection program configuration part 207 specified whole detecting elements row, but in order to improve computational speed, preferably make the detecting element row (central array of layer direction for example of 1 row of X-ray detector 102, if the multi-channel detectors of 64 row then be 32 row or 33 row of central authorities) data for projection or the data for projection of the detecting element row of the multiple row of X-ray detector 102 (central a plurality of row of layer direction for example.If the multi-channel detectors of 64 row, then be the 31st row, the 32nd row, the 33rd row, the 34th row of central authorities) data that obtain after the addition.In addition, in order to realize real-time reconstruction concurrently with scanning, also can substitute and carry out above-mentioned fladellum reconstruction, not according to the data of whole detecting elements row of the data collection mode of setting by inspection program configuration part 207 but according to the data of the detecting element row of part row (1 row or multiple row) wherein, by the cone beam reconstruction process, rebuild layer image.Cone beam reconstruction process based on the data of so a part of detecting element row also can improve computational speed.

The cone beam reconstruction process is preferably utilized the method for reconstructing that for example is called as the Feldkamp method, carries out the image reconstruction based on data for projection.The Feldkamp reconstruction method is that the subject area that will go up broad in layer direction (Z-direction) is considered as a plurality of voxels (voxel) aggregation, for the 3 dimension distributed datas that produce X-ray absorption coefficient (hereinafter referred to as " volume data (a plurality of voxel data solids (3 dimension) set forms) "), and serve as approximate reconstruction method after the improvement of basis with fladellum convolution back projection method (convolution backprojection).That is, the Feldkamp reconstruction method is considered as fan-shaped data for projection with data and carries out convolution, then along carrying out back projection with respect to rotary middle spindle corresponding to the oblique light of physical taper angle lapping.In addition,, also can handle data for projection in 3 dimension ground, carry out taper parallel (コ Application パラ) conversion (rearranging into parallel beam),, carry out 3 dimension back projections according to the data for projection after rearranging as the cone beam reconstruction process.

In addition, the fladellum reconstruction process is for example utilized fladellum convolution back projection method, in back projection, suppose that X ray (light) is orthogonal to the rotating shaft of X-ray tube 101 (supposition obtains data for projection by direction perpendicular to the X ray of Z-direction), according to the data for projection reconstructed image.

Layer image after the reconstruction temporarily is stored in the image storage part 209, and shows on display part 210.Perhaps, indication according to the operator, be transformed into the layer image of arbitrary cross-section, handle the so-called virtual 3 d image data such as 3 dimension surface images of the specific internal organs that produce from the projection image of any direction, by polishing, and, on display part 210, show via image storage part 209.

Inspection program configuration part 207 possesses keyboard, various switch and mouse etc., has the user interface function that is used for being set by the operator inspection program.Inspection program configuration part 207 has the display part (with respect to display part 210 independences or one) that is used to support inspection program, selects, generates inspection program on the setting picture that shows on the display part 210.When the parameter of setting as inspection program comprises the condition of scanning of the data that are used for collect checking object position, program, subject (patient), the recondition that is used to carry out image reconstruction, the display condition when showing the image after rebuilding, respiration exercise or the generation of the sound of scan period regularly etc.

The inspection object parts of setting object comprise head, chest, abdominal part, waist, lower limb etc., but in the present embodiment, on the setting picture of inspection program configuration part 207, show a plurality of inspection objects position, from wherein selecting chest (, then being heart) if heart is arranged the alternative.

As program, comprise from scanning and play program till the image reconstruction, play program till image transmits, play program till the image recording etc. from scanning from scanning, but in the present embodiment, select to play program till the pictorial display from scanning by inspection program configuration part 207.

As the condition of scanning, comprise the data collection mode, reconstruction scope of the collection mode of scan type, expression scanning, the condition relevant etc. with electrocardio synchronous scanning.In the present embodiment, as scan type, prepare these 3 kinds of conventional sweeps, helical scanning, dynamic scan.In the present embodiment, represent the data collection mode with the number of plies * bed thickness, storage " 64 * 0.5 ", " 32 * 0.5 " these 2 kinds of conditions can be selected any one in inspection program configuration part 207 in advance.Here, select " 64 * 0.5 ", promptly collect 64 layers simultaneously with the detecting element row by 0.5mm.Cun Chu data collection mode is not limited to above-mentioned 2 kinds in advance, also can be more than 3 kinds.In addition, with regard to numerical value, if the structure difference of X-ray detector 102 is then different certainly.The reconstruction scope is also referred to as scan period, in the present embodiment, and input in inspection program configuration part 207, setting starting position, end position.

In the present embodiment, as the condition relevant with electrocardio synchronous scanning, in inspection program configuration part 207, set with the heartbeat phase that will rebuild, heart rate mobility scale, the synchronous reconstruct mode of electrocardio (partly any one in the reconstruction/segment reconstruction), helical pitch, standard scan during the relevant condition of X ray amount etc.When having selected conventional sweep and dynamic scan, do not set helical pitch.The heart rate that converts in heart rate (Heart rate) also can be expressed as during per 1 minute, play interval (R-R at interval) till the next R ripple from certain R ripple.Here, the heart rate mobility scale is called the heart rate mobility scale.

Rebuilding heartbeat phase sets with " % " or " msec (millisecond) "." % " is that the position of establishing certain R ripple on electrocardiogram is 0%, the position of next R ripple is 100%, with 0～100% make from the R ripple play till the next R ripple during standardization, thereby performance position during this period." msec " performance is the time delay (delayed sweep time) of benchmark with the R ripple.In the present embodiment, 207 usefulness % set by the inspection program configuration part, in systems control division 212, before scanning, be transformed into time delay automatically, scan control section 201 in scanning process with time delay ms be that benchmark is controlled.

The heartbeat phase of rebuilding for example is that the operator wants the center phase place of rebuilding, the keyboards of use inspection program configuration part 207 etc. are with numerical value input arbitrarily, or the electrocardiogram of in display frame, collecting before the reading scan, and set by being mapped on the electrocardiogram.As setting heartbeat phase,, be preferably in the middle of 65～85% any one for reducing motion artifacts.In the present embodiment, set 75% as the heartbeat phase that will rebuild by inspection program configuration part 207.

The heart rate mobility scale also can be used inspection program configuration part 207 by the operator, imports for example 70～80bpm with numerical value.Also can on the curve of express time and heart rate relation, set as shown in Figure 3A with linear vernier.During with numerical value input heart rate mobility scale, be preferably in the display frame before the reading scan repeatedly the heart rate representative value of heart beating (during for example during the respiration exercise being sound generating, inspection program set any one or combination etc. in isochronous median, meansigma methods, maximum heart rate, the minimum heart rate) as with reference to information.Thus, the operator can set the heart rate mobility scale effectively.In addition, when on the curve of express time and heart rate relation, setting, can show side by side with electrocardiogram as shown in Figure 3A, also can not show electrocardiogram.

In addition, the heart rate mobility scale also can not be as mentioned above by operator input or set, and determines scope but resemble 80～100bpm etc. prior acquiescence.

And shown in Fig. 3 B, the heart rate mobility scale also can automatically be determined according to the above-mentioned representative value of the heart rate of the preceding repeatedly heart beating of scanning by systems control division 212.For example, during the respiration exercise that will obtain by systems control division 212 or inspection program is established periodic maximum heart rate and minimum heart rate is defined as the heart rate mobility scale, maximum heart rate and the minimum heart rate maybe removed the heart rate that will obtain before scanning behind minimum and maximum several hearts rate are defined as the heart rate mobility scale, or will with the meansigma methods obtained before scanning or median be the center for example 20 or the scope of 30bpm be defined as the heart rate mobility scale.

In addition, the semi-automation that the heart rate mobility scale also can be achieved as follows: the heart rate that acquiescence is presented at before the scanning of obtaining in the systems control division 212 on display part is concentrated suitable heart rate mobility scale (for example minimum heart rate, maximum heart rate), and uses keyboard etc. to edit by the operator.

In the present embodiment, be made as by the operator use inspection program configuration part 207 with numerical value input, set the heart rate mobility scale.Preferably before this is set, the navigation screen that is used to set the condition relevant with electrocardio synchronous scanning is started in inspection program configuration part 207 in display frame, at least with the input field of heart rate mobility scale, show selectionbar, the above-mentioned representative value information display field of the synchronous reconstruct mode of input field, electrocardio (half reconstruction/segment reconstruction) of the input field of the heartbeat phase of all reconstructions, the condition relevant with the X ray amount.Thus, the condition that the operator can discern and input is relevant with electrocardio synchronous scanning and other conditions are so can prevent maloperation.

As with standard scan during the relevant condition of X ray amount, comprise tube current, tube voltage etc., the operator imports for example numerical value such as tube voltage 135kv, tube current 350mA in inspection program configuration part 207.Usually, tube current is controlled by heater current.

During the so-called standard scan, be meant that the heart beat cycle to use is benchmark in the setting of specific heartbeat phase, according to the mobility scale of the heart rate of subject, expanded with specific heartbeat phase be after during the segmentation with stipulated time width at center during.Perhaps, during the so-called standard scan, be meant mobility scale according to the heart rate of subject, expanded at subject with average heart beat cycle be after during the segmentation set of benchmark during.In addition, be defined as during the segmentation collect to rebuild the required projected dataset of layer image during.

Specifically, the initial point during the standard scan is with consistent corresponding to the initial point during the segmentation of maximum heart rate (the shortest heart beat cycle), and the terminal point during the standard scan is with consistent corresponding to the terminal point during the segmentation of minimum heart rate (the longest heart beat cycle).

In the scope during this standard scan X ray is maintained high quantity of X-rays X.Even the change of the heart rate of subject also allows to keep high quantity of X-rays X.Any time during the standard scan all can be taken out the projected dataset of high SNR.Can produce the layer image of high image quality according to the projected dataset of high SNR.

Used such statement during the standard scan for convenience of description, during also can being expressed as the 1st etc.Remove in below will be between heart beat period during the standard scan during be called low quantity of X-rays X scan period (or during 2nd).In addition, also can stop to produce during the X ray during the 2nd.

In addition, during in inspection program configuration part 207, also can importing standard scan and low X ray amount scan period the two tube voltage and tube current (at this moment, preferably be constrained to can not set low X ray amount scan period the tube current value than the standard X-ray big tube current value of tube current value of scan period).In the present embodiment, tube voltage, the tube current of established standards scan period.Thus, can prevent operator's maloperation, and alleviate operator's burden.

In addition, as recondition, inspection program configuration part 207 input reconstruction modes (reconstruction of fladellum reconstruction/cone beam), reconstruction bed thickness, reconstruction interval etc.In the present embodiment, setting fladellum rebuilds as reconstruction mode.

In addition, window level, window width etc. are set as display condition for images in inspection program configuration part 207.

Like this, the inspection program of being set by inspection program configuration part 207 is sent to systems control division 212.Systems control division 212 has the program that is used to realize the inspection program set by inspection program configuration part 207, gated sweep control part 201, data for projection storage part 203, image reconstruction process portion 206 etc.Utilize the control of being all together of this systems control division 212, realize from scanning a series of programs of image reconstruction.

Systems control division 212 is read the ECG data (electrocardiosignal) of being collected by electrocardiogrph 106 with scan-synchronized ground from storage part 203, extracts for example R ripple from ECG data out.In addition, systems control division 212 reads out in the preceding ECG data of being collected by electrocardiogrph 106 of scanning beginning from storage part 203, obtains the heart rate (heart rate) of repeatedly heart beating.And then systems control division 212 bases are the heart rate of heart beating repeatedly, obtains above-mentioned representative value (meansigma methods of heart rate, maximum heart rate, minimum heart rate etc.).

And then, systems control division 212 is according to by inspection program configuration part 207 heartbeat phase and heart rate ranges (heart rate mobility scale) that set, that will rebuild, the low X ray amount scan period of determining to use the standard X-ray amount scan period that the tube current value set scans (the tube current value when scanning the heartbeat phase that will rebuild and nargin/range of error during) and scanning with the tube current value lower than this scan period in this configuration part 207 (the tube current value lower than the tube current value of standard X-ray amount scan period during).Preferably utilize from basis of calculation X ray amount scan period time delay of R ripple and with low X ray amount scan period.In addition, systems control division 212 can be set according to inspection program configuration part 207, heartbeat phase of rebuilding and heart rate mobility scale, basis of calculation X ray amount scan period and low X ray amount scan period, but preferably has storage part, according to what set by inspection program configuration part 207, heartbeat phase of rebuilding and heart rate mobility scale, settle the standard X ray amount scan period and low X ray amount scan period, wherein this storage part is used to make standard X-ray amount scan period and low X ray amount scan period to store explicitly with heartbeat phase and the heart rate range that will rebuild.

Here, use Fig. 2 to explain definite method of standard X-ray amount scan period (set tube current value during) and low X ray amount scan period (carry out synthetic low tube current value during).

The variation of the heart rate (heart rate) when Fig. 2 A is illustrated in scanning precedent such as respiration exercise, the variation of the heart rate when Fig. 2 B represents the actual scanning subject, the R ripple that Fig. 2 C collects during with actual scanning is a benchmark, be illustrated in the electrocardiogram of the maximum heart rate that obtains before the scanning, the R ripple that Fig. 2 D collects during with actual scanning is a benchmark, is illustrated in the electrocardiogram of the minimum heart rate that obtains before the scanning.In addition, the square marks of blacking is represented the heartbeat phase that will rebuild among the figure.

Shown in Fig. 2 B, the changes in heart rate when establishing scanning is 60bpm, 60bpm, 83bpm, 83bpm, 83bpm.When establish phase place that the operator wants to carry out image reconstruction be the R ripple 75% the time, it is desirable to only the square marks of blacking be exposed to the sun and penetrated X ray with standard X-ray amount (the X ray amount of the 300mAs among Fig. 2 E), do not penetrate X ray to not exposing to the sun during other.But how the heart rate in the time of can't correctly knowing scanning changes before scanning.

Therefore, this method is predicted the range of error of the heart rate of scan period according to the heart rate in a plurality of cycles of collecting before scanning.Here, shown in Fig. 2 A, because the changes in heart rate the during exercise before the scanning is 60bpm, 60bpm, 83bpm, 83bpm, 90bpm, so the change of the heart rate in when scanning is measurable for maximum heart rate is 90bpm, minimum heart rate is 60bpm.Especially, owing to similarly hold one's breath during with actual scanning during the respiration exercise, be effective so use heart rate mobility scale, maximum heart rate and minimum heart rate when the heart rate in a plurality of cycles is predicted scanning during the respiration exercise by subject.

Then, ecg information according to synchronous collection in scanning carries out pick-up to the R ripple, with this R ripple is benchmark, if 75% of the reconstruction heartbeat phase of maximum heart rate 90bpm is the starting position during the standard scan, if 75% of the reconstruction heartbeat phase of minimum heart rate 60bpm is the end position during the standard scan, remaining is defined as low X ray amount scan period.These starting positions, end position were scaled from the time delay of R ripple.X ray amount during the standard scan (perhaps, comprise in tube current value and the tube voltage value the condition value of tube current at least, relevant with the X ray amount) is suitable for the tube current value of being set by inspection program configuration part 207.The X ray amount of low X ray amount scan period or the condition relevant with the X ray amount also can automatically be determined according to imposing a condition during the standard scan.Specifically, the X ray amount of low X ray amount scan period or the condition relevant with the X ray amount be predefined for X ray amount during the standard scan or the condition relevant with the X ray amount about 1/3～1/2 (for example the setting tube current value during standard scan is 300mAs, when setting tube voltage value is 135KV, the tube current value that makes low X ray amount scan period is for setting the 1/3:100mAs of tube current value, the tube voltage value equates to be 135KV with setting tube voltage value), (for example, the tube current value is 90mAs maybe the condition relevant with the X ray amount of hanging down X ray amount scan period to be predefined for fixed value, the tube voltage value is 125KV).

In the example of Fig. 2, illustrated use maximum heart rate, minimum heart rate during establishing method, but the heart rate mobility scale is not limited to maximum heart rate, minimum heart rate, as mentioned above, when allow also applicable after from whole hearts rate of before scanning, obtaining, removing minimum and maximum several hearts rate maximum heart rate and minimum heart rate, (, then be the various values such as 60～80bpm) of its front and back 10bpm from the meansigma methods of before scanning, obtaining or median prescribed limit for example if establishing meansigma methods is 70bpm.

In addition, what present embodiment illustrated is the example that can set any range in inspection program configuration part 207 to the heart rate mobility scale, but also can be that scope at the numerical range of operator input or linear vernier is when bigger than threshold value, make and can not determine this scope (determining inspection program), so that can not use this modulation.This be because, actual patient is when scanning, the heart rate mobility scale seldom surpasses 15～30bpm, the patient that the heart rate mobility scale is big is speculated as the generation arrhythmia, so preferably directly do not use such value.

Systems control division 212 according to the standard scan of determining as mentioned above during or during the standard scan and low X ray amount scan period, be provided for controlling the synthetic X ray control signal of X ray amount to scan control section 201.For example, when the X ray control signal is LOW (low) level, apply tube voltage, the tube current that low quantity of X-rays X is used to X-ray tube 101, and produce the X ray of low X ray amount from X-ray tube 101 from device for generating high voltage 104.On the other hand, because when the X ray control signal is HIGH (height) level, apply tube voltage, the tube current (being tube voltage value, the low tube current value of setting by inspection program configuration part 207) that high quantity of X-rays X is used from device for generating high voltage 104 here to X-ray tube 101, so produce the X ray of high X ray amount from X-ray tube 101.Systems control division 212 is arranged to the LOW level in low X ray amount scan period with the X ray control signal, on the other hand, during standard scan, the X ray control signal is arranged to the HIGH level.Thus, X ray exposes to the sun with low quantity of X-rays X in low X ray amount scan period and penetrates, during standard scan, expose to the sun and penetrate with high quantity of X-rays X, even so the heart rate of subject change in scanning, also can positively obtain rebuilding the necessary data for projection of desired heartbeat phase, and can realize being not used in diagnosis during low the penetrating of being exposed to the sun.

In addition, as mentioned above, systems control division 212 is controlled, so that during standard scan with the scanning of high X ray amount, low X ray amount scan period with low X ray amount scanning, be not during standard scan, to change sharp but device for generating high voltage 104 offers X-ray tube 101 (or X ray amounts) such as tube currents from low X ray amount scan period.Be systems control division 212 shown in Fig. 2 E, between during low X ray amount scan period and the standard scan, have transition period, change at leisure from (or X ray amounts) such as tube currents of device for generating high voltage 104.In addition, systems control division 212 is controlled, so that except situation about being set by inspection program configuration part 207, the tube current that makes low X ray amount scan period is not below predetermined threshold value (tube current value).This be for from low X ray amount scan period to increase sharp during the standard scan tube current or on the contrary during the standard scan when low X ray amount scan period is reduced tube current sharp, prevent essential factor owing to the fault that causes overload to cause to X-ray tube 101 or device for generating high voltage 104.

Systems control division 212 also is all together the Spin Control that is rotated support 103, the mobile control of bed board 302 except the control of scan control section 201 being carried out the adjustment of X ray amount, provide control signal to scan control section 201 for this reason.After receiving this signal, scan control section 201 is carried out various controls according to control signal, collects data for projection.The channel number of data for projection and visual angle, X-ray detector 102, row number and electrocardiosignal (ECG data) temporarily are stored in the data for projection storage part 203 explicitly.206 pairs of data for projection that are stored in the data for projection storage part 203 of image reconstruction process portion, use the fladellum reconstruction method concurrently with scanning, connect and constantly rebuild the layer image data, (or on backstage) uses the cone beam reconstruction method after the end of scan, rebuilds the layer image data of whole scan periods.The layer image data of being rebuild by image reconstruction process portion 206 offer display part 210 via image storage part 209, and show on display part 210.

Below, the action of the X ray computer laminagraph device that constitutes like this is described.

Use the cardiac work up of the X ray computer laminagraph device of present embodiment roughly to be undertaken by respiration exercise, inspection program setting, scanning, image reconstruction, the such flow process of other processing.

At first, the operator makes subject carry out respiration exercise before scanning.During respiration exercise on subject installing electrodes, confirm correctly collecting ECG signal with electrocardiogrph 106.If the operator can confirm electrocardiogrph 106 and collect ECG signal, then carry out respiration exercise according to the respiration exercise function that is arranged in this device.The operator uses inspection program configuration part 207 to set and holds one's breath the time.Then, after the operator uses the 207 indication beginnings of inspection program configuration part, produce sound such as " please be air-breathing ", " please hold one's breath ", " please stop " from pallet device 1.During electrocardiogrph 106 is collected sound generating, be the ecg information during the respiration exercise, send to control station 2.Control station 2 sends to systems control division 212 with the ecg information that receives via storage part 203.Systems control division 212 is obtained the heart rate in per 1 cycle (between R ripple-R ripple) during the respiration exercise.

Then, formulate the inspection program of subject cardiac work up in the inspection program support function of operator in being arranged at this device.Specifically, in inspection program configuration part 207, select chest (, then being heart) as checking the object position if heart is arranged in the alternative.Selecting heart, on the setting picture of inspection program configuration part 207, show the detail parameters support information that heart is used as after checking the object position.The operator is on one side with reference to this support information, Yi Bian use input scan condition, the reconditions etc. such as keyboard, mouse of inspection program configuration part 207.As the condition of scanning, input with set scan type (being helical scanning), data collection mode (the detecting element row of being used by 0.5mm are collected the 64 layers/detecting element row used by 1.0mm simultaneously and collected 32 layers simultaneously) here, as the starting position of the scope of reconstruction and end position, the condition relevant etc. with electrocardio synchronous scanning.As recondition, comprise reconstruction mode (fladellum reconstruction method/cone beam reconstruction method), rebuild the number of plies, rebuild bed thickness etc.In the present embodiment, select the fladellum reconstruction method as reconstruction mode.

As the condition relevant, set the heartbeat phase that to rebuild, heart rate mobility scale, reconstruct mode (partly reconstruction/segment reconstruction), helical pitch, scanning speed, the condition (tube current, tube voltage) relevant with the X ray amount of standard scan scope with electrocardio synchronous scanning.

After selecting such inspection program and clicking ACK button, the information relevant with selected inspection program is sent to systems control division 212.

Systems control division 212 is according to by inspection program configuration part 207 heartbeat phase and heart rate mobility scales that set, that will rebuild, the X ray amount that settles the standard scan period and hang down X ray amount scan period.Systems control division 212 is obtained standard X-ray amount scan period and low X ray amount scan period as the time delay from the R ripple.

After the operator confirms to collect ECG signal with electrocardiogrph 106, check by inspection program configuration part 207 to begin indication.Receive after this begins index signal systems control division 212 gated sweep control parts 201, data for projection storage part 203, image reconstruction process portion 206 etc.

Scan control section 201 control pallet driving device 105 and bed driving devices 301, pallet driving device 105 makes runing rest 103 rotations, make it reach the scanning speed of being set by inspection program configuration part 207, bed driving device 301 moves to (the run-up position of helical scanning) before the scanning starting position with bed board 302.

Then, after the speed of runing rest 103 reached setting speed, bed driving device 301 slided bed board 302 edgewises (Z-direction).When the sliding speed of bed board 302 reaches constant, provide tube voltage, the tube current of setting by inspection program configuration part 207 from device for generating high voltage 104 to X-ray tube 101, penetrate X ray thereby expose to the sun.

When from device for generating high voltage 104 when X-ray tube 101 provides tube voltage, tube current, systems control division 212 is carried out following processing.

Systems control division 212 is read the ECG data (electrocardiosignal) of collecting with electrocardiogrph 106 with scan-synchronized ground from storage part 203, connects according to ECG data (electrocardiosignal) and constantly the R ripple is carried out pick-up.Then, systems control division 212 according to the R ripple of the electrocardiosignal of synchronous collection, determined standard scan during and the time delay from R ripple of low X ray amount in scan period, the X ray control signal that will be used for X ray amount modulation control sends to scan control section 201.Scan control section 201 in during standard scan in the time delay of R ripple, send the X ray control signal of expression HIGH level, penetrate high X ray amount to expose to the sun, in the X ray control signal that from the time delay of R ripple in send expression LOW level of low X ray amount in scan period, penetrate low X ray amount to expose to the sun.

The X ray control signal that device for generating high voltage 104 receives from scan control section 201, if this signal is the HIGH level, then the tube voltage that inspection program configuration part 207 is set, tube current offer X-ray tube 101.On the other hand, if are LOW level from the X ray control signal of scan control section 201, then device for generating high voltage 104 for example makes tube voltage identical with the HIGH level, and the tube current value is provided is about 1/3 tube current of HIGH level.Thus, during the standard scan (during) expose to the sun from X-ray tube 101 and to penetrate the X ray of high X ray amount, low X ray amount scan period (during) expose to the sun and penetrate the X ray of low X ray amount.During standard scan when low X ray amount scan period moves, during transition interior tube current (X ray amount) slowly descends, during low X ray amount, reach above-mentioned 1/3 tube current value (X ray amount), on the other hand, from low X ray amount scan period during standard scan when mobile, during transition interior tube current (X ray amount) slowly rises, and reaches the tube current value (X ray amount) of setting during standard scan.

Like this, under the data collection mode that sets in inspection program configuration part 207, the collection and the helical scanning executed in parallel of the electrocardiosignal of being undertaken by electrocardiogrph 106, modulation (modulation) X ray amount in helical scanning.

Detected in X-ray detector 102 through the X ray behind the subject, and be transformed into the data for projection of analog electrical signal, be transformed into by data collection circuit 107 after the data for projection of digital electric signal, send to pretreatment portion 202, accept various corrections and handle via not shown data transport unit.

The visual angle (VIEW), channel number, row number etc. of the anglec of rotation of data for projection and the X-ray tube 101 of expression during data collection are associated, and are stored in the data for projection storage part 203 of control station 2 with the ECG data (electrocardiosignal) of electrocardiogrph 106.

Image reconstruction process portion 206 is listed as the data for projection of collecting according to a part of detecting element in the data collection mode that is set by inspection program configuration part 207 (all detecting element row) concurrently with helical scanning, carry out real-time reconstruction, rebuild layer image continuously, display part 210 shows the layer image after rebuilding continuously.Then, image reconstruction process portion 206 is after helical scanning finishes or on the backstage, the data relevant with the inspection program configuration part 207 specified heartbeat phase that will rebuild (being the data for projection that utilizes the same heartbeat phase of segment reconstruction collection here) are weighted, the use cone beam is rebuild, to set image pitch and to set the image bed thickness and rebuild by a plurality of layer images in the reconstruction scope of inspection program configuration part 207 settings, display part 210 shows the layer image after cone beams are rebuild.

Like this, in the present embodiment, when modulation of X-ray amount in electrocardio synchronous scanning, by the specified reconstruction heartbeat phase of scan rebuilding not only required during, and during scanning enough and to spare under the setting X ray condition, even the heart rate of subject (R-R at interval) has change, also can realize the minimizing that being exposed to the sun of subject penetrated, and can obtain rebuilding the data for projection of heartbeat phase with the X ray amount (i.e. Qi Wang S/N image) of operator's expectation.

In addition, in the present embodiment, by settling the standard scan period according to a plurality of hearts rate and the specified reconstruction heartbeat phase of operator of before scanning, collecting, heart rate change in the time of can having predicted scanning, the scanning of range of error, so can realize the minimizing that being exposed to the sun of subject penetrated, obtain the data of the reconstruction heartbeat phase of operator's expectation really.

In addition, in the present embodiment, settle the standard scan period according to a plurality of hearts rate during the respiration exercise.Owing to similarly hold one's breath during when scanning and the respiration exercise, so the mobility scale of PHR accurately.

In addition, in the present embodiment, from a plurality of hearts rate of before scanning, collecting, maximum heart rate and minimum heart rate are carried out pick-up, as the heart rate mobility scale, so can improve the precision of prediction of the heart rate mobility scale when scanning.

In addition, in the present embodiment, can be by operator's X ray condition (tube voltage and tube current) during established standards scan period and the standard scan of low quantity of X-rays X in the middle of scan period only, so can prevent from during standard scan, to set X ray condition that low X ray uses, set the such mistake of X ray condition that high X ray is used in low quantity of X-rays X scan period.

In addition, in the present embodiment, parallel with helical scanning, data for projection according to a part of detecting element row collection in whole detecting element Herba Orobanchess of the data collection mode of setting by inspection program configuration part 207, carry out real-time reconstruction, rebuild layer image continuously, and at the layer image that shows continuously on the display part 210 after rebuilding, after helical scanning finishes or on the backstage, according to by the relevant data for projection of the inspection program configuration part 207 specified heartbeat phase that will rebuild, use cone beam to rebuild layer image.Thus, the operator can confirm layer image in real time, so can confirm whether carrying out the modulation of X ray amount according to the variation of image SD.In addition, behind the end of scan, can diagnose according to correct layer image.

And, in the present embodiment, by during the standard scan and low X ray amount between scan period transition period is set or restriction is set so that the tube current of low X ray amount scan period, can not avoided X-ray tube 101 grades are applied over load, so can prevent fault below the value at certain.

The present invention is not limited to above-mentioned embodiment, the implementation phase, can in the scope that does not break away from its main idea, element be out of shape and be put to concrete enforcement.In addition, can utilize the appropriate combination of disclosed a plurality of elements in the above-mentioned embodiment, form various inventions.Also can from the whole elements shown in the embodiment, delete several elements.

For example, in the above-described embodiment, during standard scan, scan with the X ray amount of setting the X ray condition, scan with (setting the X ray condition) low X ray amount during than standard scan in low X ray amount scan period, but also can stop, covering to expose to the sun and penetrate X ray on subject in low X ray amount scan period, or low X ray amount scan period be provided with the X ray amount be zero during.

In addition, in the above-described embodiment, illustrated by 207 settings of inspection program configuration part or by systems control division 212 and determined the heart rate mobility scales.But the heart beating mobility scale not necessarily needs to set, determine.Replacing, can be the center phase place with the heartbeat phase that will rebuild not only by inspection program configuration part 207, and input, sets the enough and to spare phase place, or determines the enough and to spare phase place according to the heartbeat phase that will rebuild.Thus, can scan with high X ray amount extraly the required data of the reconstructed center phase place at least 1 heart rate, even so in scanning, there is a little heart rate change, also can realize the minimizing of being exposed to the sun and penetrating, rebuild the image of desired reconstructed center phase place simultaneously, thereby can save the work of input, setting heart rate mobility scale.

In addition, can not set the heart rate mobility scale yet, but, determine heart rate mobility scale (or directly settling the standard scan period) according to 1 heart rate more than the heart beating in scanning process, collecting according to the ecg information before the isochronous scanning of respiration exercise.

In addition, both ecg informations are determined the heart rate mobility scale in the time of also can reaching scanning according to scanning is preceding.Before the heart rate that systems control division 212 is obtained according to the parallel ecg information of collecting in scanning process surpasses scanning during definite heart rate mobility scale, even after this in the scanning way, do not carry out the X ray modulation yet, but keep the X ray amount of setting tube current, tube voltage.Thus, even just in case the patient when producing arrhythmia etc. in scanning, also can obtain the data of the heartbeat phase that will rebuild.

And, also can not resemble and import the heart rate mobility scale by the operator the present embodiment, but by systems control division 212 according to the electrocardiogram (ECG) data of before scanning, collecting and being stored in the storage part 203, calculate the heart rate in a plurality of cycles, automatically set the heart rate mobility scale.At this moment, being not limited to maximum heart rate, minimum heart rate with the heart rate mobility scale of automatic setting as the heart rate of benchmark, also can be meansigma methods or median.

In addition, can be not yet with in the heart rate mobility scale (for example maximum heart rate, minimum heart rate) with rebuild heartbeat phase is defined as standard scan one to one during, but with set the tube current scan value after having increased some allowances (for example a few percent, a few msec) during the standard scan during.

In addition, on the display part of inspection program configuration part 207, limit to show and the relevant information of a part of heart rate between practice period of holding one's breath (for example from the heart beating several times of the beginning of holding one's breath, the heart beating several times before finishing of holding one's breath), or limit the electrocardiogram of a part of heartbeat phase of demonstration.Then, make the operator show the heartbeat phase of setting heart rate or wanting to rebuild with reference to this.As shown in Figure 3, heart rate has heart rate maximum after the beginning of holding one's breath, and slowly reduces then, and closing on holds one's breath reaches the tendency of minimum HR when finishing.Therefore, if constitute as this variation, then the operator sets on corresponding to the electrocardiogram of maximum heart rate or minimum heart rate and rebuilds heartbeat phase, thus if the consideration error lower than maximum heart rate/than the high error of minimum heart rate.At this moment, systems control division 212 is in during the standard scan, if by specified heart rate of operator or electrocardiogram is maximum heart rate, the heart rate that is lower than its 10～20bpm is calculated as minimum heart rate, to be defined as the zero hour during the standard scan corresponding to the moment of maximum heart rate, will be defined as the finish time corresponding to the moment of the minimum heart rate that calculates.When the heart rate of the heart beating several times before end is held one's breath in demonstration or electrocardiogram, if by specified heart rate of operator or electrocardiogram is minimum heart rate, the heart rate that is higher than its 10～20bpm is calculated as maximum heart rate, to be defined as the finish time during the standard scan corresponding to the moment of minimum heart rate, will be defined as the zero hour corresponding to the moment of the maximum heart rate that calculates.

And the X ray amount (or tube current value) during the standard scan of illustrating in the present embodiment is for constant, but but also multistage ground change X ray amount during the standard scan.For example, also can stipulate in accurate scan period that visual angle (for example 45 degree-135 degree, 225 degree-270 degree) is higher X ray amount (tube current value) by bidding, other visual angles (for example 315 degree-45 degree, 135 degree-225 degree) are low, according to by be used for reconstruction scope location with search (スカウト) as the data for projection collected of search sweep, the multistage the tube current value of established standards scan period.

In addition, in the present embodiment, determine to hang down the X ray amount tube current value of scan period, or set, but be not limited thereto by inspection program configuration part 207 according to the setting tube current value during the standard scan.For example, according to the data for projection that obtains by the monitor scans that is used for before heart scanning, seeking contrast agent and flows into periodic prescan, promptly carry out at the upstream side (for example cervical region) of the quantity of X-rays X heart lower than heart scanning, the real-time reconstruction layer image, and on display part 210, show the CT value or come self-shileding (マス Network) as value added the time, the tube current value that also can determine to become to establish monitor scans is a lower limit, the setting tube current value of bidding accurate scan period is the upper limit, changes the low X ray amount tube current value of scan period between upper and lower bound.Thus, the operator can not need settle the standard during scan period, the monitor scans and 3 kinds of tube current values of low X ray amount scan period, so can alleviate the work of operator's X ray condition.

And, in the present embodiment, collect the above segmentation (sheet (パ Star チ)) of 2 heart beatings and carry out segment reconstruction, but may collect unwanted owing to the relation of heart rate, rotary speed etc.For example, in the time of can in the 1st heart beating, the 2nd heart beating, these 3 segmentations of the 4th heart beating, collecting the data for projection of half scanning size (108 degree+segment angle), the part of the part of the 3rd heart beating and the 1st heart beating and the 2nd heart beating is overlapping, but, the heartbeat phase of the 3rd heart beating is also exposed to the sun penetrated X ray in order to collect the sectional data for projection of the 4th heart beating.In this case, systems control division 212 is controlled so that with the tube current value during the standard scan the 1st heart beating, the 2nd heart beating, these 3 segmentations (heartbeat phase) of the 4th heart beating are scanned, but scans with the segmentation (heartbeat phase) to the 3rd heart beating of the tube current value of low quantity of X-rays X scanning.That is, systems control division 212 when dividing intersegmental lap big, at least 1 above segmentation (heartbeat phase), is not to be defined as during the standard scan in segment reconstruction, but is defined as low X ray amount scan period.In other words, when repeatedly collecting the data at same visual angle (sheet),, and be made as low X ray amount scan period with during not being made as standard scan at least for 1 time in repeatedly.Thus, can realize the further reduction that being exposed to the sun of subject penetrated.

(embodiment 2)

Below, with reference to the 2nd embodiment of description of drawings X ray computer laminagraph device of the present invention (being also referred to as X ray CT or CT scanner).The X ray computer laminagraph device comprises: X-ray tube and radiation detector be rotation/rotation (ROTATE/ROTATE) type of rotation around subject integratedly; With a plurality of detecting elements are arranged in ring-type, the fixing/all kinds such as rotation (STATIONARY/ROTATE) type of X-ray tube rotation around the subject only, all applicable the present invention of any one type.Here, as current rotation/rotary-type the describing that accounts for main flow.

In addition, reconstruction method comprises full reconstruction method, half reconstruction method, segment reconstruction method.These reconstruction methods are rebuild 1 layer of angular range difference that the layer image data are required.X-ray tube rotation 1 layer of required required time of angular range of layer image data of reconstruction is called temporal resolution.Full reconstruction method is in order to rebuild 1 layer of layer image data, need X-ray tube revolve three-sixth turn during in the data for projection collected.Half reconstruction method is in order to rebuild 1 layer of layer image data, need rotate at X-ray tube (180 degree+α) during in the data for projection collected.α represents the extended corner of X ray, i.e. segment angle.The segment reconstruction method is when segments is n, from a continuous or discrete n heart beat cycle, collect { (180/n) data for projection in degree+α/n} scope, and gather together enough that (method of data for projection of size of 180 degree+α), the temporal resolution that this segment reconstruction method is provided is as X-ray tube rotation { (180/n) the required time of the angular range of degree+α/n}.The present invention is applicable to any one reconstruction mode.Here, be that example illustrates with half scanning method.

In addition, incident X-rays is being transformed in the mechanism of electric charge, main flow is to convert X-rays into light and then with components of photo-electric conversion such as photodiodes this light is transformed into the indirect conversion shape of electric charge with fluorophor such as flashers, and utilizes by X ray and generate the electron hole pair in the quasiconductor and the Direct Transform shape of the photoconduction electrical phenomena that moves to its electrode.As x-ray detection device, can adopt above-mentioned any one mode, but here, describe as the former indirect conversion shape.In addition, in recent years, the commercialization of wanting a plurality of right so-called multitube ball-type X ray computer laminagraph device of X-ray tube and X-ray detector is installed on rotating ring is carried out, and the exploitation of its peripheral technology is also carried out.No matter be a former pipe ball-type X ray computer laminagraph device, or multitube ball-type X ray computer laminagraph device, the present invention is applicable to any one.Here, describe as a pipe ball-type.

Fig. 5 illustrates the structure of the X ray computer laminagraph device of present embodiment.This X ray computer laminagraph device has the pallet 1 that constitutes in order to collect the data for projection relevant with subject.Pallet 1 has X-ray tube 10 and multi-channel type X-ray detector 23.X-ray tube 10 and multi-channel type X-ray detector 23 are concerned by the peristome that clips middle body, position relative to each other, be installed on the runing rest 12 of the annular that drives by 25 rotations of pallet driving device.When scanning, the subject P on the bed board 2a of bed 2 inserts in the peristome with mounting.In order to detect the electrocardiogram of subject P, electrocardiogrph 22 is installed on subject P.

With multi-channel type X-ray detector 23 adjacent settings with reference to X-ray detector 24.The X ray that sees through subject is not injected with reference in the X-ray detector 24.Detect the output intensity of the X ray of almost being decayed after producing by X-ray tube 10 with reference to X-ray detector 24, and produce its data (hereinafter referred to as the X ray dateout).Can produce other elements of the X ray dateout of expression X ray output intensity with reference to X-ray detector 24 replaceable one-tenth, the for example galvanometer of the tube current of measured X ray tube 10 (11-1 of Fig. 6), or the galvanometer of the heater current of measured X ray tube 10 (11-2 of Fig. 6).

As shown in Figure 6, placing between the negative electrode 10-3 and anode 10-2 under the vacuum state in glass tubing 10-1 applies high voltage (tube voltage) by the tube voltage generating unit 21-1 of high voltage generator 21.Provide heater current from the heater current generating unit 21-2 of high voltage generator 21 to the filament 10-4 of X-ray tube 10.The thermoelectron that produces owing to the supply of heater current quickens under high voltage, with the tungsten target collision of anode 10-2, thereby produces X ray.

Return Fig. 5.The transacter 26 that is commonly called DAS (data acquisition system) will be transformed into voltage signal from the signal that detector 23 outputs to each passage, amplify and and then be transformed into digital signal.These data are offered the computer unit 3 of pallet outside.

34 pairs of data (initial data) from transacter 26 outputs of the pretreatment unit of computer unit 3 are implemented correction processing such as sensitivity correction, the output data for projection.This data for projection is sent to the data for projection storage device 37 of computer system 3, store with time code.The ECG data of electrocardiogrph 22 also is stored in the data for projection storage device 37.

Computer system 3 is made of above-mentioned pretreatment unit 34 and data for projection storage device 37 and system controller 29, loader 39, display 38, scanning monitor 30, reconstruction unit 36, R ripple test section 42, X ray output control specialist system 43, X ray dateout storage part 41.Reconstruction unit 36 is built in handling any one of processing, half reconstruction process, segment reconstruction corresponding to full weight, but describes as half reconstruction process here.R ripple test section 42 possesses typically detect the function of R ripple as characteristic wave from the ECG data of electrocardiogrph 22; With according to this R wave period, the function of the heart rate of repeated measure subject P.

X ray dateout storage part 41 is stored the X ray dateout that is produced with reference to X-ray detector 24 by above-mentioned with time code.

X ray output control specialist system 43 has following function: promptly, explain heartbeat phase specified, that expect carry out image reconstruction via loader 39 with percentage rate according to the operator, in the heart beat cycle of subject, explain the function of setting between given period with the time (millisecond), and have according to the corresponding time width of angular range (temporal resolution) of the required data for projection of image reconstruction and the rise time of X ray, to carrying out the function of extension process between this given period; And the data between the given period after the extension process are offered the function of scanning monitor 30.Scanning monitor 30 is carried out electrocardio synchronous scanning according to the data between the given period after the extension process.That is, be benchmark with Electrocardiographic R ripple, between given period, produce X ray from X-ray tube 10, stop X ray during beyond between given period.Perhaps, be benchmark with Electrocardiographic R ripple, between given period, produce X ray with higher intensity from X-ray tube 10, produce X ray with lower intensity during beyond between given period.The modulation of generation that utilizes any one or its in tube voltage and the heater current to make up to control X ray/stop or X ray.Here, the modulation as X ray describes.In addition, also can be beyond between given period during, stop to produce X ray.

Rise time of above-mentioned X ray is defined as X ray intensity begins to reach for example required time of value of 90% of predetermined strength value (higher output valve) from almost nil value, or from predetermined for example 90% the required time of value that begins to reach predetermined strength value (higher output valve) than low intensity value.The latter's example is described here.

As shown in Figure 7, under the control of system controller 29, the preparatory stage before scanning, the breath holding test (exercise) of implementing subject (S11), by electrocardiogrph 22 measurements comprise at least during this breath holding test during electrocardiogram.In R ripple test section 42, detect R ripple (S12) according to electrocardiogram.R ripple test section 42 is when detecting the R ripple, and the interval of measure R ripple is as heart beat cycle, the shortest heart beat cycle and the longest heart beat cycle in determining during the breath holding test.Electrocardiogram shows on display 38 as illustrated in Figure 9 like that.On this picture, specify the 1st and the 2nd this 2 heartbeat phase (S13) at least via loader 39.During the 1st heartbeat phase to the 2 heartbeat phase be data for projection, the expectation images with high image quality of collecting high SN ratio rebuild during.Typically, be that 100 o'clock percentage rate (%) is specified heartbeat phase to establish during single heart beat cycle whole.For example, specify 30% and 80%.

Be transformed into elapsed time (millisecond) during X ray output control specialist system 43 is will be with percentage rate specified from the R ripple.As shown in Figure 8, at first, according to the shortest heart beat cycle determine corresponding to the 1st heartbeat phase (for example 30%), from elapsed time (being called the 1st constantly) of R ripple (S14).On the other hand, according to the longest heart beat cycle determine corresponding to the 2nd heartbeat phase (for example 80%), from elapsed time (being called the 2nd constantly) of R ripple (S15).

Then, X ray output control specialist system 43 make expectation with the high resolution image of millisecond performance, from the 1st constantly to the 2nd constantly during the initial point (the 1st constantly) of (between given period) rebuild in advance 1 layer of layer image data required, be that X-ray tube 10 rotations (180 are spent+α) time (S16) of 1/2 of required time (temporal resolution) " Δ t (180 spend+α) " here.X ray output control specialist system 43 further made for the 1st predetermined in advance constantly X ray rise time (S17).

Similarly, X ray output control specialist system 43 make expectation with the high resolution image of millisecond performance, from the 1st constantly to the 2nd constantly during time (S18) of 1/2 of terminal point (the 2nd constantly) resolution time delay " Δ t (180 spend+α) " of (between given period).

Like this, by determine according to the shortest heart beat cycle between given period initial point, according to when the longest heart beat cycle determines terminal point, expand between this given period according to temporal resolution and X ray rise time, can in electrocardio synchronous scanning, reduce the required data for projection of the image reconstruction of not collecting desired heartbeat phase or not with predetermined higher SN than the generation of collecting situations such as data for projection.

As shown in Figure 9, X ray output control specialist system 43 on the electrocardiogram during the breath holding test, at one time show on the axle among S16, determine the 1st constantly play in S18, determine the 2nd constantly during (rebuilding required scope of data) and among S17, determine the 1st constantly play in S18, determine the 2nd constantly during (between the high period of output of being scheduled to of X ray).During the requirement high resolution image, expression is with the scheduled period of high strength output X ray during the latter during the former.The operator can confirm inconsistent during two on the picture.The operator can expand or shorten the scheduled period with high strength output X ray where necessary by operation loader 39.In addition, substitute among S16, determine the 1st constantly play in S18, determine the 2nd constantly during (rebuilding required scope of data), also can show utilization by the percentage rate of the electrocardiogram of subject or the indication of specific waveforms sequence definite during (requiring the scope of high resolution image).

From X ray output control specialist system 43 to scanning monitor 30 provide 43 that determine by X ray output control specialist system, be carved into from the 1st o'clock the 2nd moment during relevant data.Scanning monitor 30 grades are mounted in the operation of the trigger button on the loader 39, beginning electrocardio synchronous scanning (S19).

Scanning monitor 30 carries out X ray modulation control in electrocardio synchronous scanning process.Scanning monitor 30 is from being begun by the 42 detected R wave impulses of R ripple detector through arriving for the 1st constantly moment after the stipulated time, X ray is modulated into high output from low output, and continue this high output state, up to beginning from the R wave impulse through till arriving the moment in the 2nd moment after the stipulated time.Scanning monitor 30 is modulated into X ray and hangs down output from being begun by the 42 detected R wave impulses of R ripple detector through arriving the moment in the 2nd moment after the stipulated time from height output.Repeat such X ray output modulation control at each heart beat cycle.

In the tempus continuum of this electrocardio synchronous scanning, will send to by the data for projection that transacter 26 is collected in the data for projection storage device 37 of computer system 3, store with time code.The ECG data of electrocardiogrph 22 also is stored in the data for projection storage device 37.In addition, the X ray dateout that is produced by reference X-ray detector 24 also is stored in the X ray dateout storage part 41 (S21) with time code.

In the tempus continuum of electrocardio synchronous scanning, when scanning monitor 30 surpasses the preset upper limit heart rate at the heart rate of subject, perhaps the heart rate of heart beat cycle faster than the heart rate of its previous heart beat cycle, when its difference surpasses preset upper limit heart rate poor (for example 19ppm), when heart beat cycle is than its previous heart beat cycle much shorter promptly, after this ends the output modulation of X ray and control (S22).As shown in figure 10, the heart rate of heart beat cycle Sn before the current time is 48, the heart rate of its previous heart beat cycle Sn-1 is 68, when both hearts rate poor " 20 " have surpassed upper limit heart rate poor " 19 ", heart beat cycle Sn+1 hereafter begins to end the output modulation control of X ray, stably keeps the height output of X ray.End control by this,, also can avoid loss of data even produce arrhythmia.

Satisfying the moment that begins from holding one's breath through predetermined end of scan condition such as stipulated time, finish scanning (S23).

As shown in figure 11, behind the end of scan, X ray output control specialist system 43 shows the ECG data that is stored in the data for projection storage part 37, and according to time code, at one time axle go up to show from be carved in the 1st o'clock that among S16, determines in S18, determine the 2nd constantly during (rebuilding required scope of data) and in S21 that X ray dateout in the X ray dateout storage part 41 is determined according to being stored in, actual with (guarantee high image quality during) during the height output generation X ray (S24).In addition, substitute from be carved in the 1st o'clock that among S16, determines in S18, determine the 2nd constantly during (rebuilding required scope of data), also can show utilization by the percentage rate of the electrocardiogram of subject or the indication of specific waveforms sequence definite during (requiring the scope of high resolution image).

X ray output control specialist system 43 detect automatically according to specified percentage rate in S13 and determine at each heart beat cycle, the expectation high resolution image during part departed from S21 between the high period of output of definite X ray the heart beat cycle (S25) of (guarantee high image quality during) according to being stored in X ray dateout in the X ray dateout storage part 41.Perhaps, also can judge and manual this heart beat cycle of specifying by the operator.Reconstruction unit 36 is removed the data for projection of collecting in detected heart beat cycle, carry out image reconstruction (S26).

According to present embodiment, can reduce the required data for projection of the image reconstruction of not collecting desired heartbeat phase or not with predetermined higher SN than the generation of collecting situations such as data for projection.

To those skilled in the art, other advantage and change are conspicuous.Therefore, the present invention is not limited to the detail and the representative embodiment that illustrate and describe here aspect its broad.Therefore, under the situation of the spirit or scope that do not break away from the defined total inventive concept of appended claim and equivalent thereof, can carry out various changes.

Claims

1, a kind of X ray computer laminagraph device is characterized in that possessing:

X-ray source produces X ray;

X-ray detector in order to produce data for projection, detects through the X ray behind the subject;

Storage part associates storage with the ECG data of described data for projection and described subject;

Specific heartbeat phase is set according to operator's instruction in the configuration part;

Reconstruction portion is come reconstructed image according to a plurality of projected datasets of collecting in striding between a plurality of given periods of a plurality of heart beat cycles;

Determination portion according to the specific heartbeat phase and the heart rate mobility scale of described subject, is determined to scan between the first phase of described subject with high X ray amount; With

Control part is controlled the tube current of described x-ray source, so that produce X ray with higher quantity of X-rays X between the described first phase, gives birth to X ray or stops to produce X ray with low ray volume production in the second phase beyond between the described first phase.

2, X ray computer laminagraph device according to claim 1 is characterized in that:

The described heart rate mobility scale basis repeatedly heart rate of heart beating is determined.

3, X ray computer laminagraph device according to claim 1 is characterized in that:

Described heart rate mobility scale instructs to determine according to the operator.

4, X ray computer laminagraph device according to claim 1 is characterized in that:

Described heart rate mobility scale is determined according to the representative value in a plurality of hearts rate of obtaining before the collection of described data for projection.

5, X ray computer laminagraph device according to claim 1 is characterized in that:

Described heart rate mobility scale is determined in the scope of maximum heart rate during respiration exercise and minimum heart rate.

6, X ray computer laminagraph device according to claim 5 is characterized in that:

Described determination portion is expanded between each described given period according to the heart rate mobility scale of described subject,

Initial point during after the described expansion is set in corresponding to the initial point during the described maximum heart rate, the terminal point during after the described expansion is set in corresponding to the terminal point during the described minimum heart rate.

7, X ray computer laminagraph device according to claim 1 is characterized in that:

Described control part is controlled the tube current of described x-ray source, so as between the given period after the described expansion and described during other internal modulation offer the tube current of described x-ray source from described device for generating high voltage.

8, X ray computer laminagraph device according to claim 7 is characterized in that:

Described control part indicates to determine tube current value between described given period according to the operator, and according to the tube current value between described given period, determines described tube current value during other.

9, X ray computer laminagraph device according to claim 7 is characterized in that:

Described control part between described given period and described during other between, the tube current value between described given period and the transition period of the tube current value between the described tube current value during other are set.

10, X ray computer laminagraph device according to claim 1 is characterized in that:

It is the time delay of benchmark that described specific heartbeat phase and heart rate mobility scale are transformed into the R ripple,

The tube current of the time delay inner control described x-ray source of described control part after conversion.

11, X ray computer laminagraph device according to claim 3 is characterized in that also possessing:

Display part, the curve that the time of the heart rate before the described scanning of demonstration expression changes; With

Operating portion is used for specifying the heart rate mobility scale on described curve.

12, X ray computer laminagraph device according to claim 11 is characterized in that:

Described display part shows the electrocardiogram during the curve of portion of time that expression comprises maximum heart rate or minimum heart rate at least and the relation of heart rate and this curve corresponding.

13, X ray computer laminagraph device according to claim 1 is characterized in that:

Described control part is controlled described tube current when breaking away from the mobility scale of described heart rate with the parallel heart rate of obtaining of the collection of described data for projection, so as described during other in the described X ray of described high X ray volume production life.

14, X ray computer laminagraph device according to claim 1 is characterized in that:

When described control part was used to seek contrast agent and flows into periodic prescan before collecting described data for projection, control described high voltage generating unit so that described tube current value during other between described given period the tube current value and the scope of the tube current value during described prescan in change.

15, X ray computer laminagraph device according to claim 1 is characterized in that:

Described reconstruction portion between described a plurality of projected datasets the identical data for projection weighting summation in visual angle.

16, X ray computer laminagraph device according to claim 15 is characterized in that:

Described reconstruction portion is suitable for and the corresponding weights of heart rate of having collected the heart beat cycle of described data for projection the identical data for projection in described visual angle.

17, X ray computer laminagraph device according to claim 16 is characterized in that:

The weights that the data for projection that suitable weights comparison is collected in the lower heart beat cycle of described heart rate to the data for projection of collecting in the higher heart beat cycle of described heart rate is suitable for are low.

18, X ray computer laminagraph device according to claim 15 is characterized in that:

Described reconstruction portion is suitable for and angular range, the described projected dataset separately shared ratio corresponding weights required with respect to image reconstruction the identical data for projection in described visual angle.

19, X ray computer laminagraph device according to claim 18 is characterized in that:

The weights that data for projection in the higher projected dataset of described ratio is suitable for are compared the weights height that the data for projection in the lower projected dataset of described ratio is suitable for.

20, X ray computer laminagraph device according to claim 1 is characterized in that:

Described data for projection is collected by helical scanning,

Parallel with described helical scanning, described reconstruction portion is rebuild layer image according at least a portion data for projection of described X-ray detector continuously by real-time reconstruction, and after described helical scanning finishes, according to data for projection, utilize cone beam to rebuild reconstructed image.

21, a kind of X ray computer laminagraph device is characterized in that possessing:

Storage part, the ecg information that storage is collected from subject;

The heartbeat phase that will rebuild of described subject is set in the configuration part;

X-ray source exposes to the sun to subject and to penetrate X ray;

X-ray detector detects through the X ray behind the described subject;

Reconstruction portion according to by the detected data for projection of described detector, is rebuild the image of the heartbeat phase of being set by described configuration part; And

Control part is controlled the tube current of described x-ray source, so as with high X ray amount scanning to rebuild the heartbeat phase set described configuration part required during add enough and to spare during after the 1st during, and during scanning the 2nd with low X ray amount or stop to produce X ray.

22, a kind of X ray computer laminagraph device is characterized in that possessing:

Be used to scan the pallet of subject, have the X-ray detector that exposes to the sun the x-ray source of penetrating X ray and detect the X ray after seeing through described subject to subject;

Storage part, the electrocardiogram that storage is collected from subject;

The configuration part, the heartbeat phase scope of the layer image of described subject is rebuild in setting;

Reconstruction portion according to the detected data for projection of described detector, is rebuild the layer image of the particular phases in the heartbeat phase scope of being set by described configuration part; And

Control part, control the tube current of described x-ray source, so that will with the parallel electrocardiogram of obtaining of described scanning as triggering, the heartbeat phase scope of setting by described configuration part with high X-ray scanning, and scan with low X ray amount and to remove the scope after the described heartbeat phase scope in the described cardiac electrical cycle or to stop to produce X ray.

23, a kind of X ray computer laminagraph device is characterized in that possessing:

Scanner section, on one side the modulation of X-ray amount carry out helical scanning on one side;

Reconstruction portion, parallel with described helical scanning, according to data for projection, utilize fladellum to rebuild and rebuild layer image in rapid succession, and after described helical scanning finishes,, utilize cone beam to rebuild reconstructed image according to data for projection; And

Display part shows with described helical scanning to walk abreast, utilize described fladellum to rebuild the layer image of rebuilding in rapid succession, and after described helical scanning finishes, shows and utilize described cone beam to rebuild the image of being rebuild.

24, a kind of X ray computer laminagraph device is characterized in that possessing:

Be used to scan the scanner section of subject, have the X-ray detector that exposes to the sun the x-ray source of penetrating X ray and detect the X ray after seeing through described subject to subject;

Storage part, the electrocardiogram that storage and described scanning are collected from subject concurrently;

The heartbeat phase of the image want to rebuild described subject is set in the configuration part;

Reconstruction portion according to by the detected data for projection of described detector, is rebuild the image of the heartbeat phase of being set by described configuration part; With

Control part, control the tube current of described x-ray source, so that according to the electrocardiogram of collecting concurrently with described scanning, in the prescribed limit that comprises the heartbeat phase of setting by described configuration part, improve the X ray amount, and in removing the scope of this prescribed limit, reduce the X ray amount or stop to produce X ray.

25, a kind of X ray computer laminagraph device is characterized in that possessing:

Storage part, the ECG information that is stored in before the described scanning and collects from subject concurrently with described scanning;

Control part, control the tube current of described x-ray source, so that will be stored in the described storage part, with the parallel ECG information that obtains of described scanning as triggering, improving the X ray amount according to being stored in a plurality of hearts rate in the described storage part, that before described scanning, collect in definite prescribed limit, and in removing the scope of this prescribed limit, reducing the X ray amount or stop to produce X ray.

26, X ray computer laminagraph device according to claim 24 is characterized in that:

Described control part is controlled described high voltage generating unit, so that make the X ray amount in the scope of removing described prescribed limit low unlike setting.

27, a kind of X ray computer laminagraph device is characterized in that possessing:

X-ray source produces X ray;

The addition handling part is between a plurality of projected datasets of collecting in striding between a plurality of given periods a plurality of heart beat cycles, that with specific heartbeat phase be the center, the identical data for projection weighting summation in visual angle; With

Reconstruction portion is according to a plurality of projected datasets behind the described weighting summation, reconstructed image.

28, X ray computer laminagraph device according to claim 27 is characterized in that:

29, X ray computer laminagraph device according to claim 28 is characterized in that:

30, X ray computer laminagraph device according to claim 27 is characterized in that:

31, X ray computer laminagraph device according to claim 30 is characterized in that:

32, a kind of X ray computer laminagraph device is characterized in that possessing:

X-ray source produces X ray;

Configuration part between given period according to operator's indication, is set between given period in the heart beat cycle of described subject;

Reconstruction portion is according to the data for projection of collecting between described given period, reconstructed image;

Extension process portion, according to the corresponding time width of angular range of the required data for projection of image reconstruction, expand between described given period; With

Control part, according between the given period after the described expansion, control is from the generation of the X ray of described X-ray tube/stop or intensity modulated.

33, X ray computer laminagraph device according to claim 32 is characterized in that:

X ray intensity height during beyond between the given period after the described expansion of X ray strength ratio between the given period after the described expansion.

34, X ray computer laminagraph device according to claim 32 is characterized in that:

Produce X ray between the given period after described expansion, stop X ray during beyond between the given period after the described expansion.

35, X ray computer laminagraph device according to claim 32 is characterized in that:

With time of 1/2 of the corresponding time width of angular range of the required data for projection of expansion and described image reconstruction respectively before and after between described given period.

36, X ray computer laminagraph device according to claim 35 is characterized in that:

Phase beginning between described given period except in advance with time of 1/2 of the corresponding time width of angular range of the required data for projection of described image reconstruction, also follow the generation of described X ray or the rise time or the suitable therewith time of synthetic described X ray in advance.

37, X ray computer laminagraph device according to claim 32 is characterized in that:

With the corresponding time width of angular range of the required data for projection of described image reconstruction be that described X-ray tube rotation is corresponding to half reconstruction method (180 degree+segment angle) the required time.

38, X ray computer laminagraph device according to claim 32 is characterized in that:

Phase beginning between described given period is according to the shortest time from a plurality of heart beat cycles that described subject is obtained determines that the prior maximum duration from a plurality of heart beat cycles that described subject is obtained of basis final period between described given period is determined in advance.

39, X ray computer laminagraph device according to claim 32 is characterized in that:

With phase beginning between described given period and the final elapsed time that is set at from described Electrocardiographic specific waveforms.

40, X ray computer laminagraph device according to claim 32 is characterized in that:

The configuration part will be the elapsed time that is transformed in phase beginning between 100 o'clock the percentage rate described given period of indicating and latter stage from described Electrocardiographic specific waveforms to establish whole described heart beat cycle by described operator between described given period.

41, X ray computer laminagraph device according to claim 32 is characterized in that:

Described control part is ended the control of the generation of described X ray/stop or intensity modulated when the heart rate of described subject surpasses the predefined upper limit and counts.

42, X ray computer laminagraph device according to claim 32 is characterized in that:

Described control part is ended the control of the generation of described X ray/stop or intensity modulated when the change of the heart rate of described subject surpasses the predefined upper limit and counts.

43, according to the described X ray computer laminagraph device of claim 40, it is characterized in that also possessing:

Measurement section is measured the output of described X-ray tube or is reflected the signal of this output; With

Storage part is stored the information that the dateout and the corresponding time of described measurement section are obtained together.

44, according to the described X ray computer laminagraph device of claim 43, it is characterized in that:

Also possess following parts: with corresponding to percentile, the scope of data in reconstruction, used of described indication and determine according to the dateout of the described measurement section of being stored, described X ray produces or keep high-intensity during, show the electrocardiogram or the described specific waveforms sequence of described subject.

45, according to the described X ray computer laminagraph device of claim 44, it is characterized in that:

Remove the data for projection of collecting in following heart beat cycle from image reconstruction process: in this heart beat cycle, the scope of data of using in described reconstruction is produced or keeps from X ray that determine according to the dateout of the described measurement section of being stored, described to be got rid of during high-intensity.

46, according to the described X ray computer laminagraph device of claim 45, it is characterized in that:

Also possesses specified parts, be used for specifying following heart beat cycle by the operator: at this heart beat cycle, the scope of data of using in described reconstruction is produced or keeps from X ray that determine according to the dateout of the described measurement section of being stored, described to be got rid of during high-intensity.

47, according to the described X ray computer laminagraph device of claim 45, it is characterized in that:

Also possess the parts that are used for the following heart beat cycle of Automatic Extraction: at this heart beat cycle, the scope of data of using in described reconstruction is produced or keeps from X ray that determine according to the dateout of the described measurement section of being stored, described to be got rid of during high-intensity.

48, according to the described X ray computer laminagraph device of claim 43, it is characterized in that:

Also possess following parts: with according to the electrocardiogram or the described specific waveforms sequence of described subject and utilize that the percentage rate of described indication determines during and determine according to the dateout of the described measurement section of being stored, described X ray produces or keep high-intensity during, show the electrocardiogram or the described specific waveforms sequence of described subject.

49, a kind of X ray computer laminagraph device is characterized in that possessing:

X-ray source produces X ray;

Reconstruction portion is come reconstructed image according to a plurality of projected datasets of collecting in striding between a plurality of given periods of a plurality of heart beat cycles, corresponding with described specific heartbeat phase between wherein said given period;

The extension according to the heart rate mobility scale of described subject, is expanded between each described given period during this time; With

Control part is controlled the tube current of described x-ray source so that produce X ray with higher quantity of X-rays X, and beyond between the given period after described expansion during in the living X ray of low ray volume production or stop to produce X ray.