X-ray installation for formation of image of examined object and its application

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to devices for formation of examined object images. X-ray installation contains at least one X-ray source, emitting polychromatic X-ray radiation, first receiver or first unit of receivers of determining values of first intensity of passing X-ray radiation, second receiver or second receiver or second unit of receivers of determining values of second intensity emitted by examined object of fluorescent X-ray radiation, correlation unit, as well as device of output for display of examined object on the basis of signals of image elements. Application of X-ray installation for formation of examined object image, which contains at least one radio-opaque chemical element is realised by X-ray radiation, passing through examined object, and fluorescent X-ray radiation, emitted by said object.

EFFECT: application of invention makes it possible to ensure display of small pathological changes with high spatial resolution with smaller dose of radiation.

22 cl, 7 dwg

The technical field to which the invention relates.

The invention relates to an x-ray machine for forming images of the examined object containing at least one radiopaque chemical element, by means of x-ray radiation, x-ray machines, as well as to the way a radio-opaque imaging of the examined object, such as a mammal, especially human.

The level of technology

Medical diagnosis using x-ray radiation is technically highly developed section diagnosis of diseases, for example, for their timely recognition, radiographic confirmation, characterization and localization of tumors, vascular diseases and other pathological changes of the human body. The technique is very effective and has a high degree of availability.

To generate x-ray radiation uses x-ray tube with a tungsten, molybdenum or rhodium rotating anodes and aluminum, copper, titanium, molybdenum and rhodium filters. Appropriate filters allow you to filter out part of the bremsstrahlung, therefore, in favorable cases, the output x-ray tube is supplied essentially characteristic radiation.

As a researcher is as receivers (detectors) used conventional x-ray film, floppy disks, hard drives or digital planar receivers. In the CT scanners used some single-line receivers or receivers with multiple rows. It is also possible parallel connection of several receivers. To directly convert x-rays into electrical signals used semiconductor receivers (detectors)based on cadmium telluride (ST), cadmium telluride zinc (CZT), amorphous selenium or amorphous or crystalline silicon (M.J.Yaffe, J.A.Rowlands, “X-Ray Detectors for Digital Radiography”, Med. Biol, 42(1) (1997) 1-39).

An example of the design of such receivers is shown in patent US 5434417 A. to ensure anarchocapitalist receiver, he dialed from multiple layers. X-rays with different energies penetrate into the receiver at different depth and due to the photoelectric effect to generate in the appropriate layer of an electrical signal, which can be directly read as the current pulse with the identification layer and, consequently, the energy of the x-ray photons.

Computed tomography (CT) has long been used in routine clinical practice. CT allows to obtain images of the body in terms of improved spatial resolution compared with conventional projection radiography. Despite the fact that the resolution tightly is t in CT is much higher than the resolution of the density in conventional x-ray techniques for more reliable recognition of many painful changes needed radiopaque agents. They improve the quality of morphological information. This contrast agent allows, on the one hand, to present the functional processes in the body (isolation, perfusion, permeability), on the other hand, to emphasize the morphology by creating contrasts (different concentration of radiopaque substances in various tissues).

In many cases, conventional rechentechnik could not be used, because the contrast of the tissue studied was insufficient. For this purpose were developed radiopaque substances that create a high radiographic density in the tissue in which they accumulate. Typical examples are iodine, bromine, elements with atomic numbers 34, 42, 44-52, 54-60, 62-79, 82 and 83 as radiopaque elements, and chelate compounds with serial numbers 56-60, 62-79, 82 and 83. From iodine compounds can be used, for example, meglumine-sodium - or lysine-diatrizoate, iothalamate, ioxithalamate, iopromide, iohexol, iomeprol, iopamidol, ioversol, iobitridol, iopentol, iotrolan, iodixanol and ioxilan (INN) (EP 0885616 A1).

In certain cases, despite the introduction of radiopaque substances, n is managed to achieve sufficient contrast fabrics. To further enhance the contrast was introduced digital subtractive angiography (DSA), in which precontrast and postcontrast images (logarithmically) are subtracted from each other. Subtraction method for use in mammography described in EP 0885616 A1: For projection mammography, there is proposed first remove precontrast mammogram, and then quickly enter the patient intravenously common orographically contrast the preparation and after about 30 sec-1 min after injection to remove postcontrast a mammogram. The obtained data of both images are correlated with each other, preferably subtract one from the other.

New developments in the field of computer tomography, with regard to the excitation radiation include, for example, for use in CT synchrotron radiation (F.A.Dilmanian “Computed Tomography with Monochromatic X-Rays”, Am. J. Physiol. Imaging, 314 (1992) 175-193). Good x-ray images can be obtained, for example, through so-called “K-edge subtractive computed tomography” (F.A.Dilmanian, R), and uses a strong increase of the absorption coefficient in the binding energy To the electrons of the atom. The element iodine is the K line at an energy 33,17 Kev. Unfortunately, this method works only with synchrotron radiation generated in large storage rings, such as DESY, because it rejected the e has a favorable way to the monochromaticity and intensity. Conventional x-ray tube not give monochromatic radiation, and the continuous spectrum. Therefore, they are unsuitable for such differential measurements.

An alternative possibility is described in the document DE 10118792 A1. Here to relieve projection mammograms proposed a method that uses x-ray sources with two x-ray anodes of different materials. For removal of mammograms, the patient is first injected radiopaque substance. This is followed by a first projection picture using the first of the two x-ray anodes, then the second projection picture using the second x-ray anode. By overlaying each individual picture element of the first image on each individual picture element of the second snapshot is made of the correlation image. Characteristic radiation of both x-ray anode is consistent with the absorption spectrum of the radiopaque substance. The radiation energy of the first x-ray anode is slightly lower energy absorption contrasting element in a radio-opaque substance, the radiation energy of the second anode is slightly higher energy absorption contrasting element. The disadvantage of this method is that conventional x-ray tube with one x is Kim anode is necessary to replace Dohnanyi tubes.

In addition to the transmission radiography describes emission radiography.

So, in document WO 2004/041060 A2 describes a device for noninvasive determination of in vivo chemical element in the prostate of a man, consisting of a probe, the system of radiation capable of exciting radiation emission of a chemical element, the radiation detector within the probe, allowing to display the detected radiation, and the system of recording, processing and display of signals in order to determine the number of chemical elements in different zones of the prostate in accordance with the displaying of the detected radiation. The emitted radiation is predominantly fluorescent radiation. In case studies of prostate preferably determined the distribution of zinc in the tissues.

Later in DE 3608965 A1 describes a method for determining the distribution of the different chemical elements in the layer of the investigated area via gamma radiation or x - rays. When this separately registered Compton and Rayleigh scattered radiation. The character defined by measuring the differential coefficient of dispersion depends on the share of different chemical elements in the separate elements of the image. Therefore, it allows to determine the share of these chemical elements. For this study area illuminated by the primary Lucio is a large number of directions, and radiation at different angles of the investigated area, is registered receiver (detector) device in various positions outside the survey area, then the resulting measure is determined by the differential coefficient of dispersion for different transmitted pulses of each picture element in the layer.

Along with this Quanwen Yu and others in the “Preliminary Experiment of Fluorescent X-Ray Computed Tomography to Detect Dual Agents for Biological Study, see J. Synchrotron Rad. (2001), 8 1030-1034, suggest the use of x-ray fluorescence to determine very low concentrations of non-radioactive substances in biomedical research. Using this method, you can produce images that allow the use of lines To_αfluorescence in one study to simultaneously detect multiagency, for example, to quantitatively record the blood flow in the brain and the density of brain cells. In this study, the images obtained by this method were compared with images obtained using x-ray transmission tomography.

However, x-ray fluorescence or x-ray scattered light described in the above publication has the disadvantage that the representation of small parts in the object under study is quite difficult because of the and difficulties of the display. Moreover, images are obtained only with coarse resolution, which does not allow to present on the image fine details.

Disclosure of inventions

Based on the foregoing, the object of the invention is to avoid these disadvantages and, above all, to create setup and ways to obtain images with different contrast chemical elements. Next, get x-rays should also be simple, convenient and economical. Study technique must be available on a wide basis. Should ensure that the display even small pathological changes in the investigated object with a high spatial resolution as low as possible dose. It is necessary to avoid image defects caused by the movement of the object.

The problem is solved using x-ray units for forming images of the examined object containing at least one radiopaque chemical element, by means of x-ray radiation according to claim 1 of the claims, the use of this plant in paragraph 11 and of the way radiopaque imaging on A.25. Preferred variants of the invention are described in dependent claims.

If the description of the invention and in the claims use the terms “IP is eskimoe radiation” and “emit”, this should be understood, first, x-ray fluorescence, i.e. the emission of radiation after excitation of irradiated matter electromagnetic radiation and, second, preferably, the Rayleigh scattering. In the latter case, the radiation without the transfer pulse is emitted again (re-radiation) of irradiated matter, however, as a result of irradiation of the electron shells in atoms of this substance does not pass into the excited state, as in fluorescence.

For imaging x-ray unit is passing through the investigated object and emitted them x-rays. For this we offer in the invention of the x-ray system includes:

a) at least one x-ray source that emits essentially polychromatic x-ray radiation,

b) the first receiver or the first set of receivers configured to determine values of the first intensity passing through the object under examination x-rays

C) a second receiver or the second set of receivers configured to determine the values of the second intensity emitted by the object under study x-rays

g) at least one block correlation made with the possibility of relating the elements of the image, values of first instance is ensenaste passing x-ray radiation with the values of the second intensity of emitted x-ray radiation, and

d) at least one output device to display the examined object on the basis of the signals of picture elements obtained by correlating the values of the first intensity values of the second intensity.

Passing x-ray radiation and the emitted x-rays can detect (detect) simultaneously or sequentially one after the other.

This x-ray unit can be used to generate images of the examined object containing at least one radiopaque chemical element, by means of x-ray radiation. Radiopaque chemical element preferably is injected into the object under examination with a radio-opaque substance that is injected into the object of study, for example in a human or animal.

Radiopaque chemical elements with low serial number, which are naturally present in the study area, give only a small output of x-ray fluorescence, therefore, the formation of images using these elements appears to be impractical. In addition, the photon energy of x-ray fluorescence in this case is small, so that their distribution in the tissues of the body slightly. In particular, since ele is enta iodine (ordinal - 53) line emission and 28,6 32,3 Kev, there are lines of fluorescence, which intensively enough to leave the investigated object and can be registered by a receiver placed outside the object. In cases of lower ordinal number of a chemical element should choose the location of the second receiver as close as possible to the study area (or selected area).

This x-ray unit used for carrying out the invention radiopaque method of research. The method includes the following operations:

a) is preferably performed organism at least one providing x-ray contrast chemical element,

b) transillumination of the investigated object essentially polychromatic x-rays

C) determining the values of the first intensity passing through the object under examination x-rays

g) determining the value of the second intensity emitted by the object under study x-rays

d) performed on the elements of the image correlation values of the first intensity passing x-ray radiation with the values of the second intensity of emitted x-ray radiation, and

e) displaying the analyzed object, based on the signal ale is now image, obtained by correlating values of the first intensity values of the second intensity.

In contrast to known methods, in which only or is the transmission x-ray computed tomography (TRCT), or detected x-ray fluorescence (fluorescent x-ray computed tomography - FRCT), in the present invention and passing the emitted radiation is measured simultaneously or sequentially and combined with each other according to the present invention, and the obtained image by the corresponding method of the correlation (correlation) are superimposed one on another. This approach allows us to use the benefits of both technologies.

The advantage of the transmission x-ray tomography is a high temporal and spatial resolution that can detect even the smallest pathological changes or other details in the study of the human body. However, the resulting contrast is often not sufficient to visualize these details. This primarily refers to the study of soft tissues. In addition, the study of certain areas of the body method TRCT difficult bony skeleton.

On the other hand, the fluorescent x-ray tomography has the advantage of extremely contrasting represent the means, as solely determined chemical elements at their respective excitation emit electromagnetic radiation, therefore, located within the study area elements can serve as extremely sensitive measuring probes. However, the method FRCT has the disadvantage that it provides only a small spatial resolution and does not allow the display of small pathological changes.

Only correlation (correlation) of intensity values passing x-rays through the elements of the invention (from one picture element to another) with the values of the intensity of the emitted x-ray radiation and the representation of the examined object on the basis of the signals of picture elements obtained by this correlation, allows you to create crisp and detailed image of the investigated area. However, the part of the image, providing contrast, has a small resolution. By relating the corresponding values with each other, you can almost completely eliminate this disadvantage, because the necessary detailed information is determined by the values of the radiation intensity measured by the method TRCT.

The invention is particularly intended for studies of the person. It can be used to obtain radiographic images for our the Oia spatial requirements, vessels and perfusion, for example pimeloda-gastrointestinal tract, for bronhografii, holographie, angio - and cardioangiography for cerebral angiography and perfusion measurements, for mammography, as well as for limfografii. The main use of the invention is a computer tomography (multislice computed tomography - computed tomography, computed microtomography imaging CMCT) and its varieties of PET (positron emission tomography), SPECT (single photon emission computed tomography), ultrasound, and other methods of optical imaging. In principle, the invention can also be used to study non-living matter, for example, in the area of material control.

For the study undergoing radiation is registered by the first receiver in the path of the rays x-ray tube, weakened the object under study. The emitted radiation is measured by the second receiver located outside of the rays, preferably at an angle of 90° to the course of the rays. This second receiver can be set and under any other angle to the x-ray beam, for example at an angle of 45° or 135° to the beam of the x-ray source, but it should not be on the path of the beam passing through the object under examination. If x Tr the BKA is in position at 12 o'clock, the conventional CT scanners are equipped with a number of receivers installed in the opposite position, for 6 hours. It is preferable to have a second receiver in position for 3 hours or 9 hours. Through this second receiver can be registered as x-ray fluorescence and x-ray scattering (Rayleigh, Compton scattering).

For selective registration of images of the second receiver using the emitted x-ray radiation can measure the energy of the emitted x-ray radiation with good resolution. In particular, preferably in the presence of a given radiating element in the object under study to distinguish (discriminate against, or highlight) received by the second receiver of x-ray radiation from a radio-opaque element, from the other emitted x-ray radiation, such as scattered radiation (Compton, Rayleigh radiation and fluorescent radiation of other chemical elements. This allows a very clear picture of certain areas of research using, for example, accumulation of radiopaque chemical elements in certain organs of the human body, using a large contrast between the highlighted radiation tissue and surrounding tissues. Even obuslovlen what I bone the skeleton structure of the resulting image in this case, recedes into the background in comparison with the image of the tissue, so bone skeleton practically does not interfere with the image.

For detection and characterization of the emitted radiation is preferably used energy dispersive receiver. However, you can use this simpler receivers and to determine the characteristics of the radiation through x-ray optics modules (combination of filters, monochromators).

In addition, this principle is likewise possible to transfer the measured values of intensity passing x-ray radiation from the first receiver. In this case, is achieved by selective image zones in the studied object, which accumulate radiopaque chemical elements.

Thus, the invention also allows the contrast to show the soft tissue, for example, in the human body. By harmonizing energy or energy interval registered receivers and passing the emitted x-ray radiation to form the radiopaque element can be achieved enhancing contrast in comparison with other methods.

To generate x-rays, you can use common available on the market x-ray tube with a continuous spectrum, for example a tube with molybdenum, tungsten or rhodium anode. Depending on the type with which ergasias in the studied object radiopaque chemical element on the anode voltage, providing a continuous radiation, for example in the range above 100 Kev.

In principle, the x-ray source can be operated without outgoing radiation, resulting polychromatic radiation falls on the object under examination, in the whole region of the spectrum. However, to reduce the radial load on the investigated object, you can also filter this x-ray emission spectrum of polychromatic x-ray source, whose energy is not required or desired for detection. This is used, for example, aluminum or copper filter, which filters out energy in the range of ≤20 Kev (soft radiation). Thus, under continuous spectrum should understand x-ray radiation in the range ≥0 Kev, preferably ≥15 Kev, more preferably ≥17 Kev and particularly preferably ≥20 Kev to 100 Kev, and no spectral range within these limits does not stand out compared to others and is not excluded. The upper limit of the spectrum of the radiation is determined by the voltage applied to the x-ray anode.

Low-energy radiation is preferably filtered to exclude hazardous to the human body radiation dose.

Usually the research object with the polychromatic x-ray radiation used in isoamsa appropriate receiver. Alternatively, you can use the energy receiver to determine the energy falling on the object of photons.

There are two fundamentally different versions of energy-dispersive detectors, and blocks receivers:

(a) a description of the energy dispersive receivers-type cadmium(zinc -) technicaly receivers is contained in the introductory part. This serial number of receivers allows the image elements to measure x-ray spectra of x-ray radiation.

b) Use a simple x-ray receivers. Before the receiver is set to the discriminator, which in the simplest case represents an appropriate combination of filters. However, for energy selection, you can also use monochromators, custom, for example, x-ray fluorescence is introduced into the body radiopaque substance.

C) however, it is technically possible to configure the receiver directly to a radio-opaque substance. So, you can use godelieve-(zinc-)technicalia or dispersive-(zinc-)technicalia receivers.

In all cases, the receiver is possible, therefore, to measure the minimum Compton scattering.

To determine the values of the intensity and energy of emitted research the subject to the object x-ray radiation detected photons are divided into at least two different energy ranges, containing, for example, the line emission To_αand K_β. To increase the specificity of the elements in some cases, you can enter a correction for Compton scattering. However, as the following examples show, this is not always required.

If you refuse inherent in x-ray images of contrast, it is possible to carry out the proposed in the invention of a way to enter into the test object, for example a human body, the radiopaque substance. A radio-opaque substance can be entered, for example, interline or parenteral, primarily in the form of intravenous, intramuscular or subcutaneous injection or infusion. After this is done the x-ray. Suitable such radiopaque substances in the selected area of the spectrum themselves have a high attenuation coefficient. Radiopaque substances, an absorbent element which has a K-edge absorption spectrum in a selected spectral range, are also quite suitable. Such radiopaque materials contain a radiopaque chemical elements with atomic number 35 or more 35 (this is, for example, bromine radiopaque substances), with atomic number 47 or 47 more (we are talking about, for example, containing iodine radiopaque substances), with a serial number 57 or bol is above 57 (it is, for example, radiopaque substances containing lanthanides, especially about the radiopaque substance containing gadolinium), or with a serial number 83 (here we are talking about the radiopaque substance containing bismuth). Therefore, using the radiopaque substance containing radiopaque chemical elements with atomic numbers from 35 (bromine) to 83 (bismuth). Suitable radiopaque radiopaque substance with chemical elements having a sequence number from 53 (iodine) to 83 (bismuth), and also with a serial number from 57 or more 57 (lanthanides) to 83 (bismuth), and particularly preferred radiopaque substance with the chemical elements that have serial numbers 57-70 (lanthanides La, CE, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb).

Suitable containing iodine contrast agents are, for example, compounds containing triodia aromatic hydrocarbons, primarily amidotrizoate, iohexol, iopamidol, Lobanova acid, ipodnova acid, iopromide, Sapronova acid, jobidon, yotalamova acid, iopentol, ioversol, ioxaglate, iotrolan, iodixanol, eurocinema acid, laxapana acid, ioxitalamic acid and josemanuel (INN). Brand names for radiopaque substances containing iodine are Urografin® (F. Schering), Gastrografin® (Is. Schering), Biliscopin® (F. Schering), Ultravist® (F. Schering) and Isovist® (F. Schering).

As radiopaque substances are also used metal complex compounds, such as Gd-DTPA (Magnevist® (F. Schering)), Gd-DOTA (Gadoterate, Dotarem), Gd-HP-DO3A (Gadoteridol, Prohance® (F. The Bracco)), Gd-EOB-DTPA (Gadoxrtat, Primavist), Gd-BOPTA (Gadobenat, MultiHance), Gd-DTPA-BMA (Gadodiamide, Omniscan® (F. Amersham Health)), Dy-DTPA-BMA, Gd-DTPA-Polylysin, cascade polymers Gd-DTPA and others, and DTPA = diethylenetriaminepentaacetic acid, DOTA = 1,4,7,10-tetraazacyclododecane, HP-DO3A = 10-(hydroxypropyl)-1,4,7,10-tetraazacyclododecane-1,4,7-trioxane acid), EOB-DTPA = 3,6,9-triaza-3,6,9-Tris(carboxymethyl)-4-(4-ethoxybenzyl)undecadienal acid, WORTH = (4-carboxy-5,8,11-Tris(carboxymethyl)-1-phenyl-2-oxa-5,8,11-trustregion-130-OIC, Benik-oxide), DTPA-BMA = diethylenetriaminepentaacetate-bis(methylamide), DTPA-polylysine = diethylenetriaminepentaacetate-polylysin, cascade polymers DTPA.

Radiopaque substances can be used enterline or parenteral. Parenteral application of the preferred intravenous (i.v.). Preferred dosages for containing the non-ionic iodine contrast agents are dose of 0.75 g/kg body weight. This corresponds to about 6 mmol/kg body weight. Further dose can preferably be increased to 1.5 g/kg body weight (equivalent to about 12 mmol/kg body weight), and in exceptional cases is Ah - to 2 g (i.e. 16 mmol) or 5 g (39 mmol) of 1 kg of body weight. For lanthanide complex compounds preferred dose is 0.1 mmol/kg body weight. Suitable and preferred doses up to 0.3 mmol/kg body weight, or up to 1 mmol/kg body weight.

Spectral line emission gadolinium correspond 43,0 and 48.7 Kev, i.e. these values are higher than for iodine, for which they are 28,6 32,3 and Kev. Complex compounds of metals can instead of gadolinium atoms include, for example, all other lanthanides, especially lanthanum or ytterbium.

Digital receivers for some time are produced by different manufacturers (for example: The BBI Newsletter, February 1999, p.34; H.G.Chotas, J.T.Dobbins, C.E.Ravin “Principles of Digital Radiography with Large-Area, Electronically Readable Detectors: A Review of the Basics”, Radiol, 210 (1999) 595-599). Often they consist of amorphous silicon or other semiconductor materials. In the proposed invention in an x-ray machine used primarily for the following receivers: receivers with phosphor plates (e.g., F. Fuji Chemical, Konica), amorphous silicon (for example, F. GE Medical, Philips Medical, Siemens Medical), selenium (e.g., F. Philips Medical, Toshiba), with hyposulphite of gadolinium (e.g., F. Kodak), with semiconductor elements made of cadmium telluride (ST) or cadmium telluride zinc CZT), with oxyorthosilicate yttrium, oxyorthosilicate lutetium, yo is the home of sodium or bismuth germanate. Especially good results are obtained with the so-called S(Z)T receivers, i.e. receivers, made of semiconductor material is cadmium telluride (C(Z)T).

Detailed description of the design energy dispersive receiver of a semiconductor material described in the patent US 5434417 A. In this case, provides a segmented semiconductor layer irradiated by x-rays from the face side. Energy travels in the semiconductor material and begins to interact with the semiconductor material. The penetration depth depends on the energy of x-ray photons. At higher energy x-ray photons of the radiation penetrates deeper than at lower energy x-ray photons, until you begin to interact with the material of the receiver and under the action of the photoelectric effect to generate the current pulse. Current pulses in the individual segments of the receiver can be removed from the installed electrical contacts. The current pulses are processed in a pre-amplifier.

The receiver, first, can be made planar type. In this embodiment, all elements of the image are recorded simultaneously and sent for analysis in block correlation. In this case, the receiver is a flat map of a separate detector sensitive e the elements (sensors) is preferably in the form of a matrix, in which the detector is sensitive elements arranged in rows and columns.

Secondly, there may be a block of receivers, which serves to measure the emitted x-ray radiation and is arranged to form images in the emitted rays, and this is made with x-ray optics module for energy selection.

Instead of the planar receiver can also be used lowercase receivers or matrix from multiple receivers to capture a certain image element. In such receivers the x-ray emission from the studied object simultaneously in the x-ray optical fibers. Many of these fibers are combined in the planar receiver.

In addition, the receiver may be configured to register one individual picture element and is mounted for movement to register all image elements. In this embodiment, the receiver during the measurement can only register volatile intensity in the individual picture element. The intensity values of the individual picture elements are recorded sequentially, for example line-by-line for further processing are sent to the block correlation.

In addition, the receiver may contain a matrix detector sensitive elements stored which contains a matrix detector sensitive elements, each of which is configured to register the respective picture element mounted for movement to register all image elements. Under the matrix detector sensitive elements according to the present invention is understood as a line detector sensitive elements and other circuit detector sensitive elements, such as a table. In this embodiment, the receiver registers the intensity values of the individual elements of the image line by line, or in some cases block. For the registration of all intensity values of the receiver during the measurement is moved preferably perpendicular to the main axis of the matrix. Defined in the measurement of the intensity values can be processed in the block correlation.

To form images, such as the distribution of radiopaque chemical elements in the object under study, it is advisable to register the intensity of the radiation emitted by the corresponding spatial elements with the same value. Further, for this purpose it is expedient also to influence the spatial elements of the radiation of the same intensity from the x-ray source. However, in practice it turns out that these assumptions are only conditionally, because this one is second hand, incident x-ray radiation in the investigated object in varying degrees attenuated by absorption depending on the path taken by the ray to the receiver, and, on the other hand, the radiation emitted by the spatial elements in the studied object, depending on which way the rays in the object of investigation must still go to the receiver, in varying degrees, weakened self-absorption.

This problem is inherent to all emission-spectroscopic methods. In order to solve the problem, the values of the second intensity is first adjusted taking into account the absorption of the incident x-ray radiation and/or self-absorption of the emitted x-ray radiation in the object of investigation, and only after this adjustment is carried out by elements of the image correlation values of the first and second intensity. This correction can be performed using digital techniques, based on the geometric shape of the investigated object and at least approximately spatially dependent density of x-ray radiation. To determine the spatially dependent density x-ray you can use the images obtained by the values of the first intensity. To determine the spatially dependent absorption and self-absorption can be is in a first approximation be obtained by measuring the spatial dependent density of x-ray radiation, since the absorption coefficients transmitted and emitted x-rays are identical.

Next, taking into account self-absorption of emitted radiation may be advisable to change the position and angle of the second receiver relative to the survey area during the measurement, such as arc trajectory to compensate for the structural heterogeneity in the studied object, which depending on the angle and location can have different absorbing action. The image in this case can be obtained after the correction by averaging.

Processed in the pre-amplifier signal is then sent to at least one block correlation, in which the intensity of the passing x-ray radiation from the element images of the examined object is correlated with a picture of the emitted x-ray radiation (x-ray scattering and x-ray fluorescence) from the same image element. The block correlation can serve as a processing unit programmed accordingly.

For correlating the intensity of photons of both modalities (image transmitted (transmission) and emitted (emission) rays) they elementwise compared to each other, preferably are subtracted one from the other or divide one by the other. To establish a correlation from element to element image in one case, to use the comparator, and in another case, a separating element. Of course, to correlate intensity values transmitted and emitted x-ray radiation from the element image allows you to perform other mathematical operations.

For processing the measured intensity values of the picture element preferably provides for the following devices that can be implemented in the processing unit:

G1), the first storage device, configured to save the image elements, the values of the first intensity passing x-ray radiation,

G2) a second storage device, configured to save the image elements, the second intensity of emitted x-ray radiation (e.g., I, Gd, Yb),

G3) computing device which has a capability of a corresponding correlation of both the formed image datasets and, thus, allowing on the basis of data from a data set obtained in the transmitted beams, and data obtained on the basis of the emitted x-ray radiation, preferably x-ray fluorescence, to generate or calculate a set of data from the images.

This allows to correlate intensity values of all elements of the image to be transmitted and emitted radiation, and the picture of the emission of characteristic spectral lines of emission configured to be used a radio-opaque substance. If you are using a mixture of radiopaque substances (for example, Ultravist® and Gadovist®) or substances containing iodine, and any lanthanide (primarily Gd or DY), we can draw the corresponding characteristic spectral line emission for imaging in the emitted rays, and the measured data sets, then the elements of the image are correlated with each other and are used to form the image, or alternatively, the image elements are correlated, the corresponding intensity values and the received data is then used to form the image. To this end, the data element is passed to the output device, which contains, for example, a monitor (cathode-ray tube or liquid crystal) or a plotter.

The invention is explained in more detail in the following figures and examples. To get a first hand view of the principle of the invention, it was decided to abandon the correction of the measured x-ray spectra is consistent with the absorption of the exciting beam and self-absorption.

Brief description of drawings

In the drawings shown:

figure 1 - view of the experimental device in CT

figure 2 - diagram of the device for acquiring images or experimental devices

figure 3 - scheme of the experimental device for generating the first phantom measurements,

figure 4 spectra of the radiation phantom of figure 3, filled with water (figa), drugs Ultravist® (figb), Gadovist® (pigv),

figure 5 spectra of the radiation phantom of figure 3, filled with water (figa), drugs Ultravist® (figb), Gadovist® (pigv), and in each case between the receiver and the phantom was set polymetylmetacrylate plate thickness of 5 cm,

figure 6 - the radiation intensity depending on the position / displacement of the phantom of figure 3 in the selected areas (in accordance with the lines To_αand K_β)(iodine: figa, gadolinium: figb, a mixture of iodine and gadolinium: fegv),

figure 7 - types in the context of computed tomography (transmission image) phantom filled with Gd, a mixture of iodine/Gd, iodine, air and water.

The implementation of the invention

Figure 1 presents a photograph of the experimental device in a computer tomograph with a rubber ball 1, mounted on a tripod 2. The rubber ball is located in the center of the computer tomograph. In various experiments the rubber Sha which was filled with air, water and various radiopaque substances. The ball was between the tube computed tomography (over a rubber ball; the figure not shown) and line receiver (under the table located under the rubber ball; figure not shown).

At a 90° angle to the line connecting tube of a computer tomography, a rubber ball and the receiver was installed measuring chamber 3 to determine x-ray fluorescence. This experimental device was modeled filled with radiopaque substance, tissue, tumor or other fragment studied in computer tomography of the object. For this object layers was determined by simultaneously measuring the scattering spectra.

Used for this experience of the experimental device shown in detail in figure 2. On this diagram you can see the ball 1, which is known as phantom was in the isocenter of the rack 4. Tube 5 CT scanner was located at 12 o'clock and was fixed in this position. The measuring chamber 3 consisting of a receiver 6 and a lead tube 7 was verified at a 90° angle to the conical x-ray beam emanating from the tube computed tomography and aimed at the phantom (Orb) (in the z-direction; see arrow).

To detect x-ray radiation was used receiver CZT 6 with those crystal is lurida cadmium-zinc size 3 mm × 3 mm × 2 mm and orifice 100/400 μm (F. Amptek Inc., USA). Registered fluorescent receiver data transmitted from the receiver via the amplifier 8 in the multichannel analyzer 9, and then displayed in graphical Excel® spreadsheet (Microsoft)stored in the memory of the personal computer 10. Thus, the intensity of the signal SI=SI(E) can be processed in digital form as a function of energy E.

Figure 3 presents a scheme of the experimental device for generating the first phantom measurements. Part of the measuring chamber 3 for measuring the fluorescence is depicted in the left part of the figure, and in the middle of the screen shows the number 1. A separate section plane located vertically in figure 3, from which fluorescent radiation enters the measuring chamber was generated falling from above fan-shaped x-ray beam. The dotted lines mark the position of the tube computed tomography over the cut-out image. The horizontal scale indicates the offset of the fan-shaped beam and, consequently, the corresponding section plane (Horny layer) in the ball.

“Zero dimension” was performed at the level of +45 mm, i.e. outside of the exciting beam.

After each shooting range measuring device was moved 10 mm further into the matrix (in the z-direction), and registered with the new range. So layers had various spectra in the depending on the ball position in the beam or in accordance with the geometry of the ball.

Thus, the measuring device possible to measure x-ray fluorescence, depending on the topography of the phantom, and at z=-60 mm to show the layer closest to the receiver, and at z=0 is the layer most remote from the receiver (hence, at z=-60 mm own absorption of radiation is minimal, and at z=0 maximum; due to the spherical geometry, the absorption effect is visible also in the transmitted beam at elevated concentrations radiopaque substance).

Example 1

At the first measurement balloon was filled with water, and at 80 kV, 50 mA 80 with each position of the ball along the beam path according to figure 3 was produced radiation measurement (parameters: receiver XR-100.CZT (aperture 0.1 mm), the distance from the ball to the receiver: 18.0 cm, the distance from the balloon to the tube of the x-ray scanner: 32,0 cm).

On figa shows scattering spectra of water in the phantom for different provisions.

When the second dimension, the balloon was filled with a solution of 50 mmol/l of iodine in water (Ultravist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement (parameters: receiver XR-100.CZT (aperture 0.1 mm)).

The spectra of radiation in various positions presented on figb). Line To the_αand K_βiodine (28,6 32,3 and Kev) are clearly visible in the figure. Graphic shows the dependence of the measured intensity of R is nenovsky fluorescence from the geometry of the phantom. The greater the thickness of the transparent layer of the phantom, the higher was measured intensity.

When the third dimension ball was filled with a solution of 50 mmol/l gadolinium in water (Gadovist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement (parameters: receiver XR-100.CZT (aperture 0.1 mm)).

The spectra of radiation in various positions presented on figv. Line To the_αand K_βgadolinium (43,0 and 48.7 Kev) are clearly visible in the figure. It was found that the intensity of the measured radiation especially in the area of K-lines depends on the geometry of the ball in the box beams.

Example 2

When individual measurements in this experiment between the receiver and the phantom was set polymetylmetacrylate plate thickness of 5 cm to simulate the self absorption of the fluorescent x-ray emission surrounding tissues.

On figa presents scattering spectra of water in the phantom for different provisions.

When the second dimension, the balloon was filled with a solution of 50 mmol/l of iodine in water (Ultravist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement (parameters: receiver XR-100.CZT (aperture 0.1 mm)).

Received radiation spectra for different positions presented on figb. Installed polymetylmetacrylate plate weakened the intensity of the fluorescent radiation is Oia. It was confirmed that the intensity was less than the greater thickness. However, even with the greatest thickness of the layer of the ball (in the middle), K-line was still measurable.

When the third dimension ball was filled with a solution of 50 mmol/l gadolinium in water (Gadovist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement (parameters: receiver XR-100.CZT (aperture 0.1 mm)).

Received radiation spectra for different positions presented on figv. Here the fluorescent radiation also helped set polymetylmetacrylate stove. Because the lines To the_αand K_βgadolinium have the meanings respectively 43,0 and 48.7 Kev, in the presence of polymetylmetacrylate plates were found significantly more intense fluorescence emission than in the previous case of iodine emissions. So in this case, even when the maximum thickness of the layer of the ball (in the middle), K-line could be measured.

Example 3

In another experiment was determined and recorded values of fluorescence intensity depending on the position of the ball relative to the x-ray beam.

At the first measurement balloon was filled with a solution of 50 mmol/l of iodine in water (Ultravist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement.

On figa shows the dependence of intensive the STI fluorescent radiation from the position / displacement of the phantom in selected energy ranges, the relevant lines To the_αiodine when 28,6 Kev and lines To_βiodine when 32,3 Kev. On this figure you can see the beam intensity profile due to the shape of the ball.

POI second dimension, the balloon was filled with a solution of 50 mmol/l gadolinium in water (Gadovist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement for each position.

On figb shows the dependence of the intensity of fluorescent radiation from the position / displacement of the phantom in selected energy ranges, the corresponding line To the_αgadolinium when 43,0 Kev and lines To_βgazolina when 48,7 Kev. On this figure you can also see the beam intensity profile due to the shape of the ball.

When the second dimension, the balloon was filled with a solution of 25 mmol/l of iodine in water (Ultravist®) and 25 mmol/l gadolinium in water (Gadovist®), and at 80 kV, 50 mA 80 with each position of the ball was made radiation measurement.

On FIGU shows the dependence of the intensity of fluorescent radiation from the position/displacement of the phantom in selected energy ranges, the corresponding line To the_αiodine when 28,7 Kev line To the_βiodine when 32,3 Kev line To the_αgadolinium when 43,0 Kev and lines To_βgadolinium when 48,7 Kev. As can be seen from FIGU, the profile of the ball with the direct application of signal intensity as a function of the position of the playback IMEI : is found unsatisfactory. This is due to the absorption side of the excitation and self-absorption-side radiation, which distort the image. Small concentrations of radiopaque substances and amendments to the absorption of the primary beam and the self absorption of x-ray fluorescence lead to one-dimensional reproduction of the ball.

Example 4

7 shows registered computed tomography species in the context of the previous examples of x-ray fluorescence. Top left to right down presents an image for ball filled with gadolinium, a mixture of gadolinium and iodine, iodine, clean water and air. Balloon filled with air, obviously, gives the lowest attenuation of x-rays, followed by a balloon filled with water. When using a balloon filled with a solution of 50 mmol/l radiopaque element, the attenuation of x-ray radiation is more pronounced than when filled with water, a quantitative analysis is possible by defining units of Hounsfield (HU), but only the involvement of images of x-ray fluorescence allows to judge about the filling of the balloon with one or other chemical elements.

1. X-ray unit for forming an image of the examined object containing at least one radiopaque chemical element, through rentgenovskogo radiation, passing through the object under examination and fluorescent x-rays emitted by the specified object, containing:
a) at least one x-ray source that emits essentially polychromatic x-ray radiation,
b) the first receiver or the first set of receivers configured to determine values of the first intensity passing through the object under examination x-ray
C) a second receiver or the second set of receivers configured to determine the values of the second intensity emitted by the object under study fluorescent x-ray
g) at least one block correlation made with the possibility of relating the elements of the image values of the first intensity passing x-ray radiation with the values of the second intensity of emitted fluorescent x-rays, and
d) at least one output device to display the examined object on the basis of the signals of picture elements obtained by correlating the values of the first intensity values of the second intensity.

2. X-ray installation according to claim 1, characterized in that the block correlation includes the following devices:
G1), the first storage device, executed with the capability, the capacity of save the image elements of the first intensity passing x-ray radiation,
G2) a second storage device, configured to save the image elements of the second intensity of emitted fluorescent x-ray
G3) computing device, configured to correlate the image elements of the first intensity passing x-ray radiation with the values of the second intensity of emitted fluorescent x-rays.

3. X-ray installation according to one of the preceding paragraphs, characterized in that the second receiver or the second set of receivers configured to determine a second intensity values with a resolution depending on the energy of the emitted fluorescent x-rays.

4. X-ray installation according to claim 1, characterized in that the second receiver or the second set of receivers allows to distinguish the fluorescent x-rays emitted contained in the object under study radiopaque chemical element from another emitted x-rays on his energy.

5. X-ray installation according to claim 1, characterized in that the correlation of the first and second intensity values for the image elements is carried out after pre-correction taking into account the absorption of the incident x-ray emission and/or self-absorption of the emitted fluorescent x-ray radiation in the investigated object.

6. X-ray installation according to claim 1, characterized in that the first and/or second receiver is a receiver in the form of a flat matrix.

7. X-ray installation according to claim 1, characterized in that the first and/or second receiver configured to register one individual picture element and is mounted for movement to register all image elements.

8. X-ray installation according to claim 1, characterized in that for determining the emitted fluorescent x-rays provided the second set of receivers, made with x-ray optics module for energy selection.

9. X-ray installation according to claim 1, characterized in that the first and/or second receiver contains a matrix detector sensitive elements, each of which is configured to register the respective picture element mounted for movement to register all image elements.

10. The use of x-ray installation according to one of claims 1 to 9 for forming an image of the examined object containing at least one radiopaque chemical element, by means of x-ray radiation passing through the object under examination, and fluorescent x-rays emitted by the specified object.

One of claim 10, characterized in that perform the following operations:
a) scanning the examined object is essentially a polychromatic x-ray radiation,
b) determining values of the first intensity passing through the object under examination x-ray
C) determining the value of the second intensity emitted by the object under study fluorescent x-ray
g) running through the elements of the image correlation values of the first intensity passing x-ray radiation with the values of the second intensity of emitted fluorescent x-rays, and
d) displaying the analyzed object on the basis of the signals of picture elements obtained by correlating the values of the first intensity values of the second intensity.

12. The use of claim 10, wherein the value of the second intensity is measured with a resolution depending on the energy of the emitted fluorescent x-rays.

13. The use of claim 10, wherein the fluorescent x-rays emitted contained in the object under study radiopaque chemical element, distinguished by its energy from another emitted x-ray radiation.

14. The use of claim 10, wherein mapping the first and second the x values of the intensity of the picture elements is carried out after the pre-correction taking into account the absorption of the incident x-ray radiation and/or self-absorption of the emitted fluorescent x-ray radiation in the investigated object.

15. The use of claim 10, wherein the provided first and second receivers or the first and second blocks of receivers.

16. The application of clause 15, wherein the first and/or second receiver is a receiver in the form of a flat matrix.

17. The application of clause 15, wherein the first and/or second receiver configured to register one individual picture element and is moved to register all image elements.

18. The application of clause 15, wherein the first and/or second receiver contains a matrix of detector sensitive elements, each of which is configured to register the respective picture element and is moved to register all image elements.

19. The application of clause 15, wherein to determine the emitted fluorescent x-rays provided the second set of receivers, made with x-ray optics module for energy selection.

20. The use of claim 10, wherein the radiopaque chemical element selected from the group comprising bromine, iodine, lanthanides and bismuth.

21. The use of claim 10, wherein the object is a mammal, and radiopaque chemical element with an introd the n in the body of a mammal.

22. The use of claim 10 for graphical or numerical representation of the studied area in the test object containing at least one radiopaque element.