CN1012705B - X-ray image-photographing device - Google Patents

Abstract

The present invention relates to a two-dimensional X-ray image photographic device. The present invention is characterized in that a collimator board provided with a plurality of small holes which are close to one another and are arrayed vertically and horizontally is arranged between an X-ray source and a photographic plane so that the collimator board can move vertically and horizontally. On the photographic plane, only the data of X-ray intensity exceeding a certain standard value (using the maximum value of the X-ray intensity received by each pixel each time as a reference) is used as the effective X-ray intensity of the pixel to be recorded; then, the data is utilized for reconstructing an X-ray image. The present invention has good effect on removing scattered X-rays.

Description

X-ray image-photographing device

The invention relates to the camera of the X ray image of two dimension such as radioscopy image.

In the middle of the photography of two-dimensional x-ray image, because scattered x-ray can make the contrast of image reduce, the sharpness of influence image, so, must eliminate scattered x-ray.

For this reason, adopt the aperture plate shape collimating apparatus that is approximately 0.5mm at interval to be used as the collimator that X-ray radiography is used before.But the elimination effect of scattered x-ray is undesirable.In addition, as eliminating the effective device of scattered x-ray, can use the X ray camera that broad X ray is constrained in the interior fan type beam of flat beam or be constrained to thin-line-shaped microminiature beam.But the X ray of x-ray source radiation is to be transmitted in the broad solid angle, and this device has only utilized the X ray in the wherein extremely limited narrow and small solid angle to photograph, so the utilization factor of X ray is low, the time that photography needs is long.

In the above-mentioned method of using collimator before, or do not make the utilization factor of X ray fall too lowly but the elimination effect of scattered x-ray is bad; The elimination of scattered x-ray is effective and utilization factor X ray is very low, exist the two conflicting relation like this, the purpose of this invention is to provide a kind of utilization factor of X ray that neither makes and fall too lowly, can eliminate the X ray image-photographing device of scattered x-ray influence again effectively.

The device that the present invention adopts is: have a lot of close mutually, and be contained between the photographic plane of x-ray source along the collimator plate of the aperture of direction arrangement in length and breadth, make it to move along direction in length and breadth, on photographic plane, only the X ray intensity that surpasses a certain standard value (maximal value of the X ray intensity that at every turn receives with each picture element is a benchmark) is got off as the data recording of the effective X ray intensity of this picture element, then, utilize these data that the X ray image reconstruction is come out again.

The 1st figure represents the structural drawing of an embodiment of apparatus of the present invention; The 2nd figure is the front elevation of collimator plate among this embodiment, the 3rd figure is the curve map that the X ray intensity data changed when a pixel scanned at every turn on the picture of the foregoing description, the 4th figure is a key diagram of explaining the principle of the invention, and the 5th figure is the curve map of the X ray Strength Changes of any on the mobile caused picture of collimating apparatus aperture.

In the 4th figure, S is an x-ray source, and C is a collimator plate of the present invention, the aperture h that only drawn on the figure, and the object that B is videotaped, I are photographic planes.The X ray intensity level at a picture element P place on the photographic plane is certain, by the object decision that is videotaped.Now, consider not have the ideal situation of scattered x-ray earlier, if move collimator plate C, at this moment shown in the 5th figure a, can see by the hole h on the collimator plate from the P point whole x-ray source during, the X ray intensity at picture element P place is certain, when the part that does not have the hole on the collimated device plate of x-ray source is blocked fully, the X ray intensity vanishing at picture element P place, therefore, the X ray intensity at this place is trapezoidal variation.But, in fact have scattered x-ray to exist, so real situation of change is the 5th figure b.Therefore,, just be defined as the standard of selection,, so, just can eliminate the influence of scattered x-ray basically fully if only the X ray intensity that surpasses 1 just be can be regarded as the valid data of the X ray intensity of P with 1 on the 5th figure b for the P point.

The 1st figure represents one embodiment of the present of invention.S is an x-ray source, and C is a collimator plate of the present invention, and the object that B is videotaped, K are pickup systems, and in this embodiment, pickup system is made of X ray picture image intensifier II and gamma camera VD.

The 2nd figure is the front elevation of collimator plate C, and a is the situation that aperture h arranges by go dish grid, and b is the situation of aperture h by interlacing dislocation cross arrangement.The diameter of aperture h is about 1mm, the minimum distance of adjacent aperture is about 10mm, collimator plate is made with plumbous, thickness is about 1mm, be clipped in aluminium sheet or mould between the plate, make it to remain tabular, rely on the drive unit Dr of the 1st figure, make it when along continuous straight runs is reciprocating, move in vertical direction again.No matter reciprocating scope or the scope that vertically moves all design to such an extent that be a bit larger tham distance nearest between aperture h, making with the x-ray source is the seamlessly inswept photographic plane of the projection of aperture h on photographic plane at center.

In the pickup system K of the 1st figure, II is an image intensifier, and the X ray image on the photographic plane is transformed to optical image on the face, then, utilizes lens L that optical image is focused on the sensitive surface of camera tube VD.CPU is the computing machine of control usefulness, and digital form is adopted in the scanning on the camera tube VD, and the prescribed level sweep trace is made up of 1024 points, and inswept 1024 horizontal scanning lines just resolve into 1024 * 1024 picture elements to the X ray image.Picture on the camera tube VD scanned repeatedly by 1/30 second cycle.The picture intelligence of camera tube output is stored into video memory M and goes up and each pixel corresponding address through the A/D conversion.CPU this scan certain picture element picture intelligence intensity data greater than among the storer M with this picture element corresponding address remembered current before data the time, CPU just only makes the data of this address into the data of current scanning.Like this, when CPU predicts collimator plate C along traverse motion, the regulation that has been along the longitudinal movement apart from the time, just stop the top course of work.At this moment, the data of the last memory of video memory M are exactly to have eliminated the picture data of the X ray image of scattered x-ray influence.

The 3rd figure represents that a certain pixel on the camera tube scans the variation of the picture intelligence of output at every turn, according to the course of work of the foregoing description, selects maximal value, as the X ray intensity of this picture element from the variation of this output.

For the control mode of CPU, can also this circulation be carried out after the several times repeatedly the above-mentioned course of work as a circulation, just can obtain the mean value of the maximum picture intelligence of the each round-robin of this picture element.In addition, also can adopt following mode.Use the 1st and the 2 two video memory, beginning, earlier without collimator plate, run-down X ray image is recorded at this moment picture intelligence in the 1st storer, as raw data.

Then, collimator plate is inserted again, made it mobile, the standard 1 that each picture element is selected according to the data regulation of the 1st storer for this picture element, if obtained surpassing the picture intelligence of 1 standard, is just imported it the corresponding address of the 2nd storer.

In the above-described embodiments, what pickup system used is image intensifier and gamma camera, and still, so long as can become picture segmentation pixel and each pixel is adopted the mode of data processing, the present invention be suitable for any pickup system.

According to top said structure, the present invention uses the collimator plate of aperture by two-dimensional arrangements, eliminated the influence of scattered x-ray object face by means of aperture, so, compare with the device that uses fan type beam or microminiature beam, basically all utilized simultaneously from x-ray source and be radiated X ray in the wide solid angle, therefore, the utilization factor height of X ray, in addition, because the effect of scattered x-ray is in the outside of collimator plate aperture projection on the face of resembling, mobile collimator plate makes being projected on the image planes none and sweeping time with omitting of aperture, passes through data processing, only adopt near the data that resemble each picture element on the face when being positioned on this picture element the center of above-mentioned aperture projection, thereby eliminated the influence of scattered x-ray, so the effect of eliminating the scattered x-ray influence is also very high.

Claims (1)

1, a kind of X ray image-photographing device comprises: a collimator plate is contained in x-ray source and by between the object that videotapes, is provided with the bidimensional via-hole array that is used for the X ray collimation on described collimator plate; An X ray image receiving device makes the form output that X ray image that representative penetrates from it can the plain signal of electric image; A memory is used to store pixel signal; And be used to make the device of described collimator plate with respect to described receiving trap parallel displacement; It is characterized in that the control bit moving device allows described collimator plate carry out moving on the two-dimensional direction in corresponding to the scope of the above through-hole spacing of array, so that each X-ray beam of through hole, leap image receiving device is passed in scanning; Described storer is used to store because collimator plate moves the maximal value of each pixel signal that is scanned pixel.

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