Summary of the invention
At present, the predose of fluoroscopy arranges and has nothing to do with subject invidual, and that is, all persons under inspection use fixing predose, or the front dosage once checked.But the X-ray predose that is subject to of thinner person under inspection may higher than the dosage needed for it, and more fat person under inspection may start with lower dosage, thus before reaching target dose, be subject to unnecessary additional radiation.
Given this, technical problem to be solved by this invention is to provide a kind of method reducing fluoroscopy dosage, can arrange predose, make it closer to target dose according to the build of person under inspection.
The present invention is that to solve the problems of the technologies described above the technical scheme adopted be propose a kind of method reducing fluoroscopy dosage, and be applicable to a fluoroscopy device, the method comprises the following steps: measure the thickness of person under inspection; Check dosage-person under inspection's thickness relationship curve according to one, determine the initial inspection dosage of this person under inspection; According to this initial inspection dose emission X-ray, person under inspection is checked; And according to obtained person under inspection's image, adjustment checks dosage, again checks, until obtain acceptable person under inspection's image to person under inspection.
In one embodiment of this invention, said method is also included in pre-configured this inspection dosage-person under inspection's thickness relationship curve in this fluoroscopy device.
In one embodiment of this invention, said method is also included in this fluoroscopy device and uses the initial stage, by the human sample inspection of predetermined quantity, sets up this inspection dosage-person under inspection's thickness relationship curve.
In one embodiment of this invention, the step setting up this inspection dosage-person under inspection's thickness relationship curve comprises: carry out fluoroscopy to the human sample of predetermined quantity; Preserve a series of target doses-person under inspection's thickness data of fluoroscopy; And matching is carried out to this list of target dosage-person under inspection's thickness data, to obtain this inspection dosage-person under inspection's thickness relationship curve.
In one embodiment of this invention, the step setting up this inspection dosage-person under inspection's thickness relationship curve also comprises: carry out segmentation to this inspection dosage-person under inspection's thickness relationship curve; Calculate in each segmentation, the average criterion dosage under between person under inspection caliper zones.
The present invention also proposes a kind of fluoroscopy device, comprises thickness detector, thickness detector, X-ray producer, picture receiver and aligner.Thickness detector, in order to before starting inspection, measures the thickness of person under inspection.X-ray producer checks dosage-person under inspection's thickness relationship curve in order to the thickness and one according to this person under inspection, determines the initial inspection dosage of X-ray, and adjusts this initial inspection dosage according to a feedback signal.Picture receiver, receives X-ray through the image produced after person under inspection.Aligner is according to the quality of this image, and what provide dose titration feeds back signal to this X-ray producer.
In one embodiment of this invention, pre-configured this inspection dosage-person under inspection's thickness relationship curve in this fluoroscopy device.
In one embodiment of this invention, this fluoroscopy device, at the use initial stage, by the human sample inspection of predetermined quantity, sets up this inspection dosage-person under inspection's thickness relationship curve.
The present invention is owing to adopting above technical scheme, dosage-person under inspection's thickness relationship is checked by introducing, make the initial inspection dosage before each fluoroscopy closer to obtaining the target dose that can receive image, thus decrease the X-ray radiation dosage that person under inspection is subject to.
Detailed description of the invention
Fig. 1 illustrates fluoroscopy device structure, as exemplary implementation environment of the present invention.With reference to shown in Fig. 1, fluoroscopy device 100 comprises X-ray producer 102, X-ray tube 104, pointing instrumentation 106, is subject to inspection platform 108, picture receiver 110 and aligner 112.
X-ray producer 102 can provide X-ray predose to X-ray tube 104.At this, KV/mA (namely voltage and current is long-pending) is exemplarily used to weigh the inspection dosage of X-ray.Below, the inspection dosage of X-ray will be represented with KV/mA value.X-ray tube 104 launches X-ray, through pointing instrumentation 106 and person under inspection 10, arrives picture receiver 110.According to the picture quality received, aligner 112 produces feedback signal and is supplied to X-ray producer 102.X-ray producer 102 calibrates the x-ray dose weighed with KV/mA according to feedback signal.
Above-mentioned calibration flow process can circulate, until x-ray dose reaches target dose.
In different applications, calibrating flow process may use different KV/mA data sets to carry out Dose Calibration.Each KV/mA data set can form curve as shown in Figure 3, and in curve, abscissa is electric current (unit mA), and vertical coordinate is voltage (unit K V).The increase of electric current or voltage or reduction carry out along curve.Suppose that O point is target KV/mA point, when initial KV/mA point is for A point, the feedback signal of aligner 112 can show that current KV/mA exceedes desired value, and Dose Calibration can towards Dir2 direction; Otherwise when initial KV/mA point is for B point, the feedback signal of aligner 112 can show that current KV/mA is less than desired value, and Dose Calibration can towards Dir1 direction.Desired value is the value that equipment reaches needed for acceptable picture quality.
Therefore initial KV/mA is more close to desired value, and the time that equipment carries out calibrating is shorter, thus the unnecessary dosage being applied to person under inspection is fewer.
Consider the relation of person under inspection's build and required x-ray dose (weighing with KV/mA in the present embodiment), can be tested by multisample, set up the corresponding relation between x-ray dose and buman body type in advance.Such as, represent build with the thickness of human body, in fluoroscopy device, set up KV-thickness curve and mA-thickness curve.Then, when checking person under inspection, measuring the thickness of person under inspection, determining initial KV/mA accordingly.
Fig. 2 illustrates person under inspection's thickness measure schematic diagram according to an embodiment of the invention.With reference to shown in Fig. 2, pointing instrumentation 106 is installed thickness detector 107.After equipment 100 has designed, SID (Source ImageDistance, source images distance) be known, by the distance D2 between inspection platform 108 surface and picture receiver 110 surface, the thickness of X-ray tube 104 and pointing instrumentation 106 and D3, and the thickness of thickness detector 107 is fixed values, thickness detector 107 can detect acquisition by thickness detector 107 to the distance D4 on person under inspection 10 surface.Thus person under inspection's thickness D1 obtains by following formulae discovery:
D1=SID-D2-D3-D4-D5
It should be pointed out that the structure of fluoroscopy device 100 is diversified, therefore the mode of person under inspection's Thickness sensitivity is not limited to above-described mode.When implementing, those skilled in the art should have the ability carry out thickness setting detector according to concrete fluoroscopy device structure and measure person under inspection's thickness.
Fig. 4 illustrates KV-thickness curve, mA-thickness curve Establishing process figure according to an embodiment of the invention.With reference to shown in Fig. 4, in the circulation of step S11-S13, fluoroscopy device 100 carries out multisample inspection.This process can use the initial stage to carry out at fluoroscopy device 100.In step S11, carry out fluoroscopy to subject invidual, in checking process, fluoroscopy device 100 can use thickness detector 107 to detect and obtain person under inspection's thickness.Meanwhile, equipment 100 can record obtain can acceptance pattern as time corresponding target KV/mA value.In step S12, equipment 100 can preserve target KV-person under inspection thickness and target mA-person under inspection thickness data.In step S13, if judgment device completes the specimen inspection of some, then enter step S14.Otherwise return step S11.
In step S14, according to existing target KV-person under inspection thickness data and target mA-person under inspection thickness data fit object KV-person under inspection's thickness curve and target mA-person under inspection thickness curve.Fig. 6 A illustrates exemplary target KV-person under inspection thickness curve, and Fig. 6 B illustrates exemplary target mA-person under inspection thickness curve.In one embodiment, these target KV-person under inspection thickness curves and mA-person under inspection thickness curve can be used, according to detected person under inspection's thickness determination target KV/mA value.But consider that the one-to-one relationship of target KV/mA-person under inspection thickness is not very accurate, in the embodiment shown in fig. 4, preferably carry out segmentation in step S15 to curve, the quantity of segmentation does not limit.In step S16, between the person under inspection caliper zones in each section of curve, average criterion KV/mA value can be calculated respectively.When fluoroscopy, when person under inspection's thickness falls into a certain interval, select the target KV/mA value in this interval corresponding as initial KV/mA value.The mode of this improvement is actually and smoothed curve is become staged curve.
Like this, the person under inspection of build thinner (thickness is also less) is when being checked, lower initial KV/mA value will be obtained, and build more fat (thickness is also larger)) person under inspection when being checked, because they and target dose are close, can effectively reduce useless roentgendosis.For curve shown in Fig. 3, these initial KV/mA values can more near target KV/mA value O.
In one embodiment, fluoroscopy device, such as, in generator 102 configurable default KV-thickness curve and mA-thickness curve, when checking at every turn, use this curve to determine initial KV/mA value, then by calibration convergence target KV/mA value.
In another embodiment, fluoroscopy device does not have pre-configured KV-thickness curve and mA-thickness curve, but by the process shown in Fig. 4, oneself sets up KV-thickness curve and mA-thickness curve gradually.
No matter whether configure KV-thickness curve and mA-thickness curve, fluoroscopy device all can be configured to the ability having and carried out fair curve by follow-up sample collection.
Fig. 5 illustrates x-ray dose calibration flow chart according to an embodiment of the invention.Referring to describing this flow process shown in Fig. 1, Fig. 2 and Fig. 5, in step S21, fluoroscopy device 100 checks person under inspection's thickness by thickness detector 107.Then, according to KV-thickness curve and mA-thickness curve in generator 102, or the average criterion KV/mA under the different-thickness interval calculated according to this curve, determine an initial KV/mA value.In step S23, fluoroscopy device 100 utilizes this KV/mA value to determine initial X-ray dose, launches X-ray from X-ray tube 104, and start to check person under inspection, picture receiver 110 will form the image at person under inspection's raying position.In step S24, if aligner 112 thinks that the picture quality obtained is better or can accept, then directly enter step S26, otherwise in step S25, aligner 112 provides and feeds back signal to generator 102, adjusts KV/mA value, then return step S24 by the latter.
Be appreciated that, the initial KV/mA value determined according to KV/mA-thickness curve may not be exactly the current specific target KV/mA value individual by inspection, but this initial KV/mA is by than situation more this target KV/mA value of convergence not using KV/mA-thickness curve, thus reduce the unnecessary x-ray dose that person under inspection is applied.
Although the present invention discloses as above with preferred embodiment; so itself and be not used to limit the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when doing a little amendment and perfect, therefore protection scope of the present invention is when being as the criterion of defining with claims.