DE2622383A1 - Scanning gamma radiation detector - producing a three-dimensional image using crystals responding to separate collimator aperture arrays - Google Patents

Abstract

A gamma ray imaging system includes a scanning head with a plurality of crystals mounted on top of a collinator formed by a lead shield containing arrays of apertures. Each apertures has a focal axis directed down to a point at which all the axes intersect at relative acute angles. Each crystals responds to radiation from a different array of apertures and produces discrete and time-significant signals as the head passes over a radiation source. The system is used medically to scan radiation dispersed within or transmitted through a patient. The signals from the crystals can be automatically processed to derive three-dimensional stereoscopic images.

Description

Scintigraph

The invention relates generally to a scintigraph or a gamma ray scanner, for mapping the local distribution of radioactive substances in the organism serves. In particular, the invention relates to a gamma ray imaging Device using a rectilinear scanning scanner and aiming to design stereoscopic images.

A gamma ray scanner contains a sensor, often also called a scanning head or measuring head to determine the gamma radiation.

The source of such gamma radiation is a radioactive material that has been introduced into a patient's body. E.g. form in the body of a patient depending on the carrier or the chemical substance in which the radioactive Substance is contained, in certain areas concentration points. By seeking out an image is obtained from these radiation concentrations.

in which the radiation concentration points are particularly highlighted are. Such an image can be displayed on a cathode ray oscilloscope.

The gamma ray imagers used heretofore make use of one Cathode ray oscilloscope for display and a measuring head for locating the radiation sources.

In addition, these devices have data processing facilities used as an ordinary computer and analog-to-digital converter with which is directly related to the radiation concentration determined by the measuring head appropriate electrical signals are converted in a suitable manner. This means that the signals must be converted into digital pulse signals, which can then be further processed by the computer.

Heretofore used gamma ray imaging devices have emerged in addition, facilities are used to detect the detected on a certain scanning path To conduct radiation like a funnel. A collimator is usually used for this purpose used. A collimator is a body made of lead with openings or channels that pull it through. The radiation can pass through the channels, but not pass through the lead body itself. So it is possible to get radiation from one determined by the radiation through the funnel-like manner Collimator is passed through, with additional apertures on the measuring head are put on 'which prevent that other radiation has access than those whose Source lies in the direction of the channels of the collimator.

The known imaging devices are used so that the The measuring head is guided along a certain straight path by being on a predetermined path is guided back and forth over the patient. The image of gamma radiation in the patient is obtained based on the information obtained during this scan collected on a straight path.

One difficulty that arises with such devices is who do not receive certain very important information of a medical nature can be. This information relates to specific radiation source concentrations in the patient's body, the position of which is outside the focal plane of the scanner is located. This depends on the ger limited to one focal plane; Wrong scanning together, which is determined by the collimator. Attempts so far made to this Difficulty overcoming were all in vain.

The invention now relates to a scintigraph with rectilinear scanning by the scintillation measuring head, the stereoscopic, i.e. three-dimensional images, is able to give. The scintigraph according to the invention differs in structure from the previously known. Instead of using a single crystal to create it of the electrical signals as a function of the one passing through the channels of the collimator Radiation or instead of a multitude of crystals, all of which are electrical at the same time Generate signals corresponding to those passing through the channels in a collimator Corresponding to radiation, there are two crystals or two separate systems used by multiple crystals to discreet electrical signals of different Channels of the same collimator. In a preferred embodiment the invention uses a crystal or a crystal group based on the Radiation responds through the channels of the collimator on its left responds while another crystal or group of crystals signals generated due to the radiation flowing through the channels of the collimator onto its got through on the right. In the preferred embodiment according to the Invention used collimator has channels, the axes of which all point to one common focal point.

Thus, in the preferred embodiment of the invention two separate channels of information stimulated at the same time. The information of the one information channel come exclusively from the right side of the collimator, while the information of the other information channel from its left side come. Neither of the two information channels uses radiation from one Collimator channel that is roughly common to both sides.

In other words, the radiation that channels in the collimator on its interspersed with right side, it is determined while completely by itself and discreetly at the same time the information about the radiation, which the passage channels on the left side of the collimator happened, separately and discreetly noted for themselves will.

The two separate channels of information then become independent further processed from each other by analog-to-digital converters and also subsequently independent and further processed for itself in the ordinary computer.

In the embodiment of the invention, the can of the two Channels simultaneously on a cathode ray oscilloscope screen projected. As the information from axes meeting each other in focus read from the collimator, a three-dimensional effect is achieved. As important Information on the stereoscopic display then appears as a so-called thin one Layer of radiation concentration at a distance from the focal plane of the scanning Measuring head can lie.

Furthermore, in the embodiment of the invention, the information of the separate channels passed through the computer to make difference calculations to carry out with it. The term "difference calculations" arose from that different response values from the same radiation concentration in the both information channels. The calculations can then be programmed through Data handling in the digital computer lead to approximate values, which was a part of an embodiment of the invention.

Understanding this operation of the above embodiment the invention is elucidated by a test run of the device. This is a test, to determine data for such difference calculations which will be obtained, by placing the rectilinear scanning scintillation probe over predetermined radiation sources is led away. These sources have certain strength or intensity and are arranged at certain distances from each other in all three dimensions. The differences the response values to the radiation emitted by these predetermined radiation sources are also caused at predetermined intervals, can then in the computer get saved. It can then make a table made by the computer from this data be set up, which represents a matrix in which the various response values to radiation and related to it, so that a relation between the unknown values of the distances and the intensities to the known ones Distance and intensity values can be produced.

Are affected by straight-line scanning of a with radiation sources Bodies, of which neither intensity nor their relative position to one another is determined the intensities are obtained as data in the two separate information channels, then you can use the matrix that has already been firmly established from predetermined values can be compared, with which it is possible, the different depths of these radiation sources to be determined or at least approximated. This makes it possible to use a mathematical To obtain a diagram, a table or the like. List from which the distance calculation carried out and the result can then be displayed. The representation of Result can be shown on a cathode ray oscilloscope by numbers, graphs or graphic representation. On the other hand, it is possible to display the shape certain data on the screen of the cathode ray oscilloscope so that the image of the radiation sources by comparison with those stored in the matrix Data can be corrected.

The aim of the invention is therefore a simultaneous discrete Sampling using separate channels with different focal planes. In this way, the difficulties that arise when you are timed are eliminated set successive scanning processes and lead to a corruption of the medically important information or to a substantial reinforcement of interfering influences or even medically unimportant information, which is considerable reduced, if not switched off at all.

In addition, a simultaneous multi-channel rectilinear one is obtained with the invention Sampling in order to be able to carry out distance calculations to determine the Depth or the offset of the radiation sources with respect to a focal plane, and in a way that is relatively cheap and using analog-to-digital converters as well as general purpose computers for the calculation, the following illustration and the correction of the data is appropriate.

Another aim of the invention is to provide an imaging device to create gamma rays with separate information channels that sharply determined and discreetly allows to determine the radiation in a way, that Data corruption is greatly reduced while scanning with previous Averages the data merging into one another in a single focal plane.

Finally, the invention aims to provide separate information channels created to obtain data corresponding to radiation concentrations, by using a collimator with a focal point that is the same for all information channels which channels will work separately to get data that makes the differences correspond in the radiation distribution in three-dimensional space.

One purpose of the invention is to provide a reference plane for achievement a uniform sensitivity before data acquisition. The raw data are in Form of signals from photo amplifier tubes. These signals correspond to the intensity radiation on a crystal between the light input side of the photo intensifier tubes and the radiation source is arranged. Because of the imperfections and the uneven ones geometric properties of the crystals, as well as because of the changes in the Radiation source itself, the raw data can be falsifications or deviations of the clinical picture. These deviations can occur prior to scanning a patient compensated by calculating mathematical compensation factors for known data using data processing devices.

Accordingly, it is an object of the invention to provide relatively large amounts of data within a short period of time with a data bus directly to be fed into the core memory of a central processing computer. - It Another object of the invention is to bypass the accumulator and make it faster To enable data to be recorded in the core memory than has previously been the case.

It is another object of the invention to keep the data in the computer memory via channels on a time share basis in order to simultaneously transfer data from different Record measuring heads, calculations based on data from another measuring head to perform and either data or derivations thereof from another measuring head map.

It is a further object of the invention to provide a device for coupling an analog-to-digital converter and a central processing computer in one system for To create scanning of radioactive medical information, the interface units are machine wired in this way to provide a relatively simple structure for a otherwise complex matrix to get.

The invention will now be based on the drawing of exemplary embodiments described and explained. They show: FIG. 1 a cross-sectional view of a part an embodiment of the invention; Figure 2 is a graphic representation of the Responding to a portion of the apparatus shown in Figure 1; figure Figure 3 is a graphical representation of the response of another portion of the device from Figure 1; Figure 4 is a cross-sectional view of a straight line scanner; Figure 5 is a graphical representation of the response of a portion of the device according to Figure 4; FIG. 6 shows the top view of a patient with the Rectilinear scan trajectory; FIG. 7 shows a vertical section through the arrangement according to Figure 6, in which the scanning plane is shown; Figure 8 is a graphical representation the response curve to a radiation source in a part of the device according to FIG 1; FIG. 9 is a graphic representation of the response curve on the same radiation source of another part of the device of Figure 1; Figure 10 is a graph the response curve to different radiation sources of the device according to the figure 4; Figure 11 is a sectional view of another preferred.

ferred embodiment of the invention; Figure 12 is a graph Representation of the response curve of part of the device according to FIG. 11; figure Figure 13 is a graphical representation of the response curve of another portion of the device from Figure 11; FIG. 14 is a sectional view of a linearly operating gamma ray scanner; figure 15 is a graphical representation of a response curve of a portion of the device from Figure 14; Figure 16 is a sectional view through part of another preferred one Execution at 9pi eles of the invention; FIG. 17 is a graphic representation of the Response curve of a portion of the device of Figure 16; Figure 18 is a graph Representation of the response curve of another section of the device from FIG 16; Figure 19 is a top plan view of a portion of the preferred embodiment of the invention, the rectilinear scanning of certain points with certain radiation intensity reproduces; Figure 20 is a graph of the response curve of a section the device of Figure 19; Figure 21 is a graph of the response curve another portion of the device of Figure 19; Figure 22 is a plan view to part of a rectilinear gamma ray imaging device; figure 23 is a graph showing the response curve of part of the device Figure 22; FIG. 24 is a graph comparing the separation of the response curves Figures 2 and 3, 12 and 13, 17 and 18 with the displacement of the radiation source from the focal plane, FIG. 25 is a graph comparing the separation of the response curves from FIGS. 20 and 2, 8 and 9 with the calculated displacement of the radiation source from the focal plane; Figure 26 is a perspective view of part of a preferred embodiment of the invention; and FIG. 27 shows a section through the part shown in FIG.

Figure 28 is a partial, schematic representation of the electronic Device for information processing according to a preferred embodiment; FIG. 29 shows a schematic representation of the angular displacements of the central axes the collimator channels or openings; Figure 29a shows the representation a signal resulting from the device shown in FIG. 32; figure 29b shows the representation of a signal that is also generated by the device shown in FIG stems from; FIG. 29c shows a signal that is generated when the device is started up is generated according to Figure 32; FIG. 30 is a plan view of the collimator; Figure 31 a schematic view of the angular arrangement of the two crystals over one single collimator according to a preferred embodiment of the invention; figure Figure 32 is a top plan view of a portion of an embodiment; Figure 33 is a perspective View of part of the device according to one embodiment; Figure 34 a partial, schematic l) representation of the electronic device with a single Crystal collimator in contrast to the schematic representation of an embodiment according to Figure 31; FIG. 35 is a graph showing the angular relationships of the central axes the collimator channels according to an embodiment of the invention; figure 35a a signal which corresponds to the functioning of the device according to FIG. 39; FIG. 35b shows an electrical signal that corresponds to the functioning of the device Figure 39 corresponds; FIG. 35c shows a signal that is generated by commissioning the device according to Figure 39 arises; Figure 36 is a flow chart representation of a Analog-digital Wanril.ers according to a preferred embodiment; Figure 37 a Flow diagram of the interface device according to a preferred embodiment, and Figure 38 is a flow chart illustration of various functions of the preferred Embodiment.

Before the invention is described in more detail, it should be noted that the invention does not apply to the construction details shown in the annex and Arrangements of the parts is limited as they are also in other embodiments embodied and can be carried out in various ways. The used Terminology is used for descriptive purposes only and is not intended to be limiting.

Figure 1 is a cross-sectional view of part of the device, which is used in a preferred embodiment of the invention. The readhead or scintillation measuring head 100 contains a collimator 102, which in its configuration corresponds to that from FIG. This collimator 102 comes with a variety equipped at an angle to each other channels 104, all with their optical central axis are aligned with a common focal point 106. Preferably these openings 104 have a hexagonal cross section.

This can be done by looking at the top of the collimator from above 102 in FIG. 27 at 108.

A crystal structure 110 is located above the collimator 102. This crystal structure 110 is divided into a left section 112 and a right section 114 divided. These two crystal sections 112 and 114 correspond to the one on the left and right part 116 and 118 of collimator 102, respectively. Photo amplifier tubes, a common one A computer and an oscilloscope are connected downstream of the arrangement shown in FIG. These are not specifically shown.

In the figure 1 is the area that is examined for its radiation is to be indicated by the conical zone 120 below the collimator. This zone converges approximately at a point 122. It then diverges again in an adjoining conical zone 124 below a focal plane 126 designated level.

All openings 104 in collimator 102 are directed to point 122.

In FIG. 1, a point 130 is indicated at which there is a radiation source is located. In the present case, this radiation source is located approximately on the Midway between focus 122 and the lower or bottom surface 132 of the collimator 102.

Figure 11 shows the same device as Figure 1, but located the point of interest here of a radiation source 134 is substantially below it the midpoint between focal point 122 and bottom surface 132 of the collimator. the The radiation source is therefore very close to the focal point 122.

In contrast, FIG. 16, which in turn uses the same device as FIG. 1 and Fig. 11 shows is one with a dot Radiation source 136 shown, which is above the middle between the focal point 122 and the collimator base 132 is located. This radiation source is therefore very close to the collimator base 132.

In the sectional view of Figure 4 is an imaging device for gamma rays similar to the device shown in Figure 1, with the exception that instead of the subdivided crystal arrangements to determine the two different ones Sides of the collimator a common crystal 140 is provided, which is on the Radiation from all openings 104 in collimator 102 is responsive. The one marked with 142 The radiation source in Figure 4 is essentially in the same position like the radiation source 130 in FIG. 1.

In Figure 14, the same device is shown as in Figure 4; here however, the radiation source 144 is located where in the device according to FIG 11 the radiation source 134 was arranged.

The graphical representation of the response curve of crystal 114 the device according to FIG. 1 is shown in FIG. The abscissa corresponds to thereby channels (the term channels is not used here in the same sense, as in connection with the passage openings in the collimator) the parts in 64 times 64 correspond to a matrix that is used to indicate the position of grid points, which are distributed over the area swept by the measuring head.

In other words, the abscissa 150 represents the position of a radiation source on the X-axis, which is perpendicular to the X-Z plane indicated in FIG is. The response to the radiation of the radiation source 130 in Figure 1 is through the pulse 152 is shown, its central axis 154 an associated Has an X value of 18 units.

The response curve shown in FIG. 3 of the crystal 112 from FIG 1 also corresponds to the radiation source 130. The abscissa is again in Direction of the Y-axis, based on the X-Z plane of the illustration from FIG. 1.

A pulse 156 has its center line 158 which has a 1 value of 32 units assigned. It goes without saying that those shown in FIGS Impulses do not represent single impulses, but a plurality of radiation images, which are caught during a certain linear displacement.

Figure 5 is a graph showing the response of the device, in particular of the crystal 140 when the device according to FIG 142 run over. The result is again recorded with falling into the Y plane Abscissa, FIG. 4 again being a representation of the X-Z plane. The device responds in the form of the pulse 160, the center line 162 of which has an X value of 25 units assigned. The total impulse corresponds to a distribution of numerous radiation recordings during a certain linear displacement. It should be noted here that the impulse 160 is approximately twice the width of pulses 152 and 156 and that the center line 162 of the pulse 160 is approximately midway between the center lines 154 and 156 is located.

In connection with Figures 2; 3 and 5 it should be noted that on the Ordinate the number of radiation determinations is plotted. Also would be it is correct, instead of the rectangular shape of the pulses, these have a Gaussian distribution to give, i.e. the shape of a bell curve. However, to that resolving power the device according to the invention to be able to better understand what follows is explained, it is more instructive to give the impulses sharply delimited contours.

Figures 12, 13 and 15 are graphical representations of response values on the radiation sources 154, 136 and 144 and that of the crystal 112 in FIG 11, the crystal 114 in Figure 11 and the crystal 140 in Figure 14, the Art the representation corresponds exactly to that of FIGS. 2, 3 and 5.

Centerline 172 of pulse 170 in Figure 12 has an X value from 2.

Centerline 182 of pulse 180 in Figure 13 has an X value of FIG. 4 and the centerline 192 of pulse 190 in FIG. 15 has an X value of 3. Regarding the latter, it should be noted that the pulse width of the pulse 190 is about twice is as big as the Breiterer Impulse 170 and 180.

Figures 17 and 18 are graphical representations of response curves of the crystals 114 and 112 of the device according to FIG. 16, which act on the radiation a radiation source 136 reacts. The representation corresponds to that of the figures 2 and 3, which also relate to crystals 114 and .112.

Figure 17 shows a pulse 200 with a center line 202 that is a X value of 40 is assigned. The X value of centerline 212 of pulse 210 in Figure 18 is 60.

It should be noted here that the height and width of the pulses 200 and 210 are practically the same. The locations of their center lines 202 and 212 on the other hand show a difference that is the distance from the common focal point 122 corresponds in the sense of a shift from a plane designated by 126.

The distance from one center line to the other, relative to the right one and the left crystal 114 and 112, respectively, is determined by the fact that the two crystals are in different spatial positions to the radiation source if they to be carried over it. It can also be observed that the position corresponding to the center line when passing the radiation source with a device FIGS. 4 and 14 are roughly on the same path between the left-hand side and the right-hand side Impulse, if recorded separately, is located. The pulse width of the with a crystal The recorded pulse is about twice as large as the width of the separately recorded right and left pulses. The explanation is that the crystal in the single crystal device according to Figures 4 and 14 is exposed to the entire radiation, in contrast to the divided crystals of the devices according to FIGS. 1, 11 and 16.

Finally it can be noted that the mutual shift of the center lines of the right and left impulses, the larger the farther the Radiation source from the focal plane 122 is her-sverlaeert.

Figure 6 shows a patient lying on a table from above, wherein the scanning path 20 of the device according to Figures 1, 4, 11, 14 and 16 through the meander line is indicated. Figure 7 shows a side view, the focal plane 230 of the scanning pad 220 is indicated.

FIG. 19 is again a top view of a table with an indicated Scanning device scan path 222, with radiation sources 231, 232 and 233 in certain arrangement both vertically above the table and horizontally indicated are, and where the relative radiation intensity of these radiation sources 231, 232 and 233 is predetermined.

The illustration of FIG. 22 as a side view of FIG. 19 leaves the relative position of the radiation sources 231, 232 and 233 with respect to the focal plane 224 of scan path 222 recognize.

Figure 8 is a graph showing the response of the crystal 114 on a portion of the path 220.

Figure 9 shows the response of crystal 112 when using the device is moved along the scan path 220.

Figure 10 shows the response curve of crystal 140 when moving along of scan path 220.

The graph of Figure 20 corresponds to the response of crystal 114 as it travels along portion 236 of scan path 222.

FIG. 21 shows a graph of the response of the crystal 112 while moving in section 236 of path 222.

Figure 23 is a graph of the response of the crystal 140 while moving in the section 236 of path 222.

Figure 24 is a graph showing the observed response in is shown on Figures 2 and 3, with the displacement from he compares the focal plane. This graph relates to the following: Figure centerline spacing dislocation d. Source 12, 13 3 20 2, 3 14 70 17, 18 20 90 The indication of the displacement of the Radiation source is a percentage based on the distance between scans head and focal plane as 100%.

The graph according to FIG. 26 compares the response curves from the FIGS. 20 and 21 with those calculated from FIG. This graph contains the following: Figure center line distance offset of radiation source 20, 21 Q R 6, 9 approximately Q approximately R In Figure 20, a pulse 240 is shown with its center line 242.

In FIG. 21, the illustrated pulse 250 has the center line 252 and In FIG. 23, the center line 262 belongs to the ZS pulse 260.

It is still to be determined that the pulse width of the pulse 260 approximates twice as big, dip the width of the Impulses 240 or 250. In addition, the center line 262 appears to be in a position on the abscissa which are about halfway between the abscissa values of the center lines 242 and 252.

Figures 20, 21 and 23 show response curves that occur during movement of the respective scanning head on path 222 in FIG. 19 due to the radiation source 231 occur.

Figure 8 shows a pulse 270 with centerline 272; Figure 9 shows a pulse 280 with a center line 282 and FIG. 10 the pulse 290 with its center line 292

The width of the pulse 290 is approximately twice as large as that Width of pulses 270 and 280. In addition, the center line 292 of the pulse lies 290 about halfway between the abscissa positions of the center lines 272 and 282.

It should also be noted that the height of the pulses 270, 280 and 290 are not is in the ratio 1: 1 to the impulses 240, 250 and 260, but the positions are relative of the center lines 272, 282 and 292 nearly or exactly equal to the positions of the center lines 242, 252 and 262.

Figures 8, 9 and 10 thus give the response of crystals 114, 112 and 140 to a radiation source 221 in the body of a patient according to FIG 6-again, in which the relative position and the intensity of the radiation source 221 was not predetermined. In contrast, Figures 20, 21 and 23 represent the Represent the response values of crystals 114, 112 and 140 to a predetermined source of radiation 231 on route 236 in Figure 19.

It can be seen from this that the center lines are closely related in Figures 8 and 20 and in Figures 9 and 21, and more precisely, corresponds the distance between the positions of center lines 272 and 282 is also the distance between the center lines 242 and 252. It can then be approximately established that the offset of the radiation source 221 with respect to the focal plane 222 is equal to the known displacement of the radiation source 231 is. By simply observing the Relationships of these same distance values as shown in the graphs of the figures 24 and 26 has happened, it can then be concluded that the separated, but simultaneous scanning with the right and left part of the radiation, which passes through the collimator, a statement about the position of the radiation source makes possible in depth.

In addition, it can be determined from the preceding description be that with the device according to the invention not only approximately on the Location in depth can be inferred by a simple examination the table with the help of the computer, but that in addition the invention is more accurate Resolution results, regardless of any calculation of this location in depth.

Furthermore, conclusions can be drawn from the preceding description be that a stereoscopic disturbance image after the kind of viewing with a right and a left eye by combining the response values of can be obtained right and left, as shown in Figures 2 and 3 are which simultaneously parallel right and left side images of the same Represent radiation source. In a modified embodiment of the invention can a viewer by supplying the received radiation image from the right and left sides of the collimator to a stereoscopic viewer, as it is used in cameras or other optical devices, the impression get an idea of depth.

Figure 28 is a diagram of a portion of the circuit; which is associated with each of the two crystals of the device. The circuit is indicated generally by the reference numeral 310. The circuit 310 consists of identical left and right areas 311 and 312, respectively. Each of these circuit areas receives signals from left and right photo amplifier tubes (PMT) 313 and 314, respectively. Each of the photo amplifier tubes 313, 314 receives light signals from the direct left and right crystals 315 and 316 arranged below them, respectively. Each of the crystals receives radiation from the left and right sides 317 and 318 of a single one, respectively Collimator 320. The openings or channels 319, 321 on the left and right sides of the collimator 320 are all aligned with a common focal point 322.

The circuits 311 and 312 are identical and are given separate ones Information from the left and right photo intensifier tubes 313 and 314, respectively. From of the left photo amplifier tube, the signals are fed into the circuit 311. The first device in this circuit is a 323 linear preamplifier. An example for the type of photo intensifier tube 313 used is the photo intensifier tube from RCA 6199 manufactured by Radio Corporation of America.

An example of a 323 linear preamplifier is the 1405 model Scintillation preamplifier manufactured by Canbarra Industries of Middleton Coamecticut.

From the linear preamplifier 323, the signals become a linear Amplifier 325 fed as a Canbars dual delay amplifier, which is called DDL amplifier, model No. 14 11 is designated. From the linear Amplifier 325, the signals are forwarded to an energy discriminator 327, as it is also manufactured by the Canbarra company and as model no. 14 31 We call it a single-channel analyzer. From the energy discriminator 327, the signals then forwarded to a computer coupling channel 329. The linear preamplifier 324, the linear amplifier 3sah, he energy discriminator 328 and the computer interface channel 330 are identical to the linear preamplifier 324, the linear amplifier 325, the energy discriminator 327 and the computer interface channel 329. The components linear preamplifier 324, linear amplifier 326, energy discriminator 328 and computer coupling channel 330 process only the signals of the right photo amplifier tube, in contrast to the components of the circuit on the left, which only contain the information of the Evaluate left photo intensifier tube 313.

The electronics shown in FIG. 28 are subsequently combined with the in Figure 34 compared. In Figure 34, the circuit is indicated generally at 340 designated. This corresponds approximately to the circuit 310 of FIG. 28, except that instead of separate left and right channels and corresponding components only one Channel and a single version of each Bnutell is provided. !) he information is only processed by a single photo amplifier tube 341, which in turn is theirs Receives information from a single crystal 342 responsive to radiation, which passes through the collimator. The electronic components consist of a linear preamplifier 344, a linear amplifier 345 and a. Energy discriminator 346, as well as one Recording circuit 347 and correspond in their Structure of the linear preamplifier 323, the linear amplifier 325, the energy discriminator 327 and computer interface channel 329.

It can be determined that the structure shown in FIG is not able to use the information according to the preferred embodiment of Invention as shown in Figure 28 to bring. This results from that no depth calculation can be carried out because the radiation is not in Form of sizes for individual channels for groups of openings added and separated is evaluated electronically from each other.

In Figure 33, an embodiment of the invention is shown in which Photo intensifier tubes 313 and 314 with separate semicircular>, disc crystals 315 or -316 are used, which take the information from a single collimator 320 refer.

FIG. 32 shows a cross section of the collimator 320 with the collimator openings 338 and the outlines of the left and right crystals 315 and 316, respectively. The outlines of the left and right side photo intensifier tubes 313 and 314, respectively, are also specified.

FIG. 7 shows a graphic representation from which the various Directional but equally large angular settlements of the center lines of the Openings directed towards a point p can be seen, the point P being the common Represents the focal point of the left and right collimator sides 317 and 318, respectively.

Figure 30 is a top plan view of the collimator showing the angular displacement the openings 319 can be seen.

It can be seen that the lower edge of one of the openings 319, whose Bottom indicated at 337, from the top edge of the same opening 339 at an angle is offset.

In Figures 29 and 35 are the angular displacements of the center lines the openings of collimators of different sizes as well as the different Response curves shown. The difference in he selectivity of the images pl, p2 and p3 is shown in FIGS. 29a, 29b and 29c, the position of the radiation sources p1, p2 and p3 in relation to the common focal point is indicated in FIG. A similar illustration is in FIGS. 35a, 35b and 35c in relation to FIG 35 given. As can be seen from Figures 29 and 35, the center lines are of the openings 319 directed to a common focal point. As from the figures 29a, 29b and 29c can be seen, the closer the radiation source, the sharper the image is at the common focus of the openings of the collimator. This arises in the same way from FIGS. 35a, 35b and 35c.

A comparison of Figures 29a with 35a, 29b with 35b and 29cit 35c shows that1 the greater the displacement of the radiation source from the common focal point of Collimator channels, the clearer the image sharpness of a small collimator is than that of a large diameter collimator. In the preferred embodiment the invention is the image sharpness of a common collimator with relatively large Diameter obtained by having different separate crystals for different Groups of openings are used.

"X" and "Y" signals are generated by an electromechanical device generated, which gives the position of the measuring head during scanning, as shown in is well known in the art. "Z" signals are related to the one above The circuit described in FIG. 33 is obtained. These signals are sent to an analog-to-digital converter 440 is entered, which is shown in FIG.

Figure 36 is a flow chart representation of an analog-to-digital converter (ADC) 440. The A-I -.! Dndler consists of a pair of gates 442, 444, via which a comparison circuit 446 is fed. 12 equivalent stresses (448, 450, 452 are shown) are also used in comparison circuit 446 for comparison purposes activated. A 12-bit register 454 is in two 6-bit registers for the X and Y components 456 and 458 split. This l, inspeis circuit for the coupling electronics is described in more detail below.

Each of the X and Y signals is passed through the corresponding gate circuits 442, 444 fed. The Z signals activate the X and Y gates 442,444, the output corresponding signals to the comparison circuit 446. One source supplies adjustable uniform pulses. These pulses are converted into 12 comparison signals divided up. Each of the comparison signals has an amplitude 1/2 of the largest comparison signal exponentiated with n, where n varies from 0 to 5.

If the raw X or Y signals exceed the comparison signal, a corresponding digit is stored in the associated 6-bit register.

FIG. 37 shows the flow diagram of the interface electronics 460. The interface electronics consists of an 8-stage buffer 462, a counter 464, marking buttons 466, an addressing selector 470 and a byte operating circuit 472. Each total Interface electronics preferably consist of integrated circuits and are instead hand machine wired as is well known in the art is. The device is designed in matrix form so that, although complicated, it Can be machine wired to make construction relatively straightforward.

The register of the A - D converter feeds a 12-bit signal into the 8-stage Latch 462. When a signal reaches the last stage of the memory, will a polling signal from the interface buffer stage 476 is generated. This polling signal is led to the data collector line 478 of the central processing computer. The traffic light line 478 outputs the signal to a priority control field 480. A processed accordingly signal 482 is returned to a device 484 through the data bus, which activates the output of the buffer stage.

A signal from the buffer output is sent to the data part 486 of the Addressing selector 470 entered. The data part 486 has 6-bit registers zJA i <(), which are assigned to the X- un <1 Y-signals, so that a number from 0 to 63 is represented can be.

Each of these numbers corresponds to a specific matrix memory location in the data matrix field 492 of the core memory of the central processing computer.

From the addressing register 494 of the address selector 470, an appropriate one Address determined. Of the Central process computer 495 has data processing functions, which can increment the data interest by the lowest bit. But certain To preserve matrix formats, it is desirable to pass the addressing register through the To advance addition of byte signals. This is done by the byte operating circuit 472 reached. The byte operating circuit is controlled by the monitor area of a program activated, which is present in an appropriate field 49f in the core memory. Through this a byte loop cycle is set in motion, as in the relevant technology is known.

The accumulator 498 can be activated by pressing the marking buttons be taken out of service. A counter 464 is kjsing by the A-D converter activated. The counter 464 prepares the interruption. The effect of the interrupt function is such a}; called cycle stealing, in which the accumulator is stopped and the data directly from the addressing selector 470 of the interface electronics 460 are transferred to the data collector line 478. The data bus 478 feeds the data then directly into the data matrix field 480 of the core memory of the host computer 495 a.

The marker buttons 466 can be operated by an operator been.

FIG. 38 shows a flow diagram with the various functions of a Embodiment of the data processing system according to the invention. It can be noted that the data recorded by the Nesskopf during the data acquisition and data transmission Data some cycles of the calculator are used to provide information with the aforementioned To process analog-to-digital converters, to transfer them to the interface electronics 460, those who Passes data to data bus 478 and they feeds into the data acquisition field (1 502.

After the end of the series of data acquisition cycles, an accumulator 498 were activated in order to transfer the data from the output field 504 to the display 505 bring, or the data that are stored in a data field 507 via a Data bus to direct disk storage, or to perform calculations the data field 507 and use the field for such a calculation and store the results in disk storage.

The features of the system described above relate to the Use of a counter that is activated by the register of an analog-digital converter output and on marking buttons operated by an operator. The accumulator activated by a monitor field to skip a subordinate function for the cycle to generate llnf1 to enable data acquisition on a "time share" basis, while other functions such as calculation, output and storage from the accumulator of the central process computer after the phase of the skipped Cycle has ended. The invention provides a method for visualizing images created, thereby enabling the operator to digitize images retrieve stored on the high-speed magnetic storage, to display them on a cathode ray tube for diagnostic evaluation.

The invention allows the operator to use the digitized images map while other functions are performed in the central processing computer will. This is done without interrupting these other functions and at the same time Time is avoided that the central process computer suppresses or loses data as a result of his extended commitment.

In a preferred embodiment of the invention, a double 64 x 64 resolution used (for both stereo pairs) as if it were the one and only Matrix size would be. There are actually three sizes available: 32 x 32; 64 x 64 and 128 x 128. To clarify the procedure, it is useful to look at a matrix of 64 x 64, it being clear that the other formats mentioned above are also possible.

Referring to FIG. 37, it should also be mentioned that the addressing selector has three components, which are divided into an addressing register and a data part are. The addressing register can also be understood as a data field register. The data part is divided into a part for the r and one for the X components. The X and Y components of the data field register are fed into the address selector.

The size changes with the different types of business Each field as follows: Operating mode 64 x 64 word data field registration: 3 bits Y: 6 bits X: 6 bits Total addressing bits: 15 bits Operating mode 64 x 64-byte data field registration: 4 bits Y: 6 bits X: 5 bits total addressing bits: 15 bits Operating mode 32 x 32 byte data field registration: 6 bits Y: 5 bits X: 4 Bits total addressing bits: 15 bits Operating mode 128 x 128-byte data field registration: 2 bits Y: 7 bits X: 6 bits Total addressing bits: 15 bits Referring to Figure 36 The register can be divided into five or more bit registers for X and Y components will. The predetermined pulse train is divided so that each of the comparison signals is exactly twice as large as the next feed signal, whereby a primary follows of up to 12 bits in a 6-bit register format.

According to a preferred embodiment of the invention, the scanner is corresponding FIGS. 1 to 27 and the associated description are built up, the signals processed by the scanner by a device such as that shown in Figures 36-13 38 is shown and described, being electronic components may be used as shown in FIGS. 28 to 35 and with reference thereto are described.

Claims (13)

Claims X Scintigraph with a scintillation measuring head and a collimator in the measuring head, thereby g e k e n n -z 0 i c h n 0 t, dvee to dcl Several crystals (112, 114) are applied to the collimator, the collimator has a lead screen for gamma radiation, groups (116, 118) of passage channels in the collimator (102) Let gamma radiation pass, the axes of the passage channels (104) a common point (122) below the collimator (102) are directed, this Point (122) lies on the optical axis for all passage channels (104), like also in a focal plane (126), the radiation of which from the measuring head (100) through its Openings (104) are received in the collimator (102), each crystal element (112, 114) electromagnetically to the radiation of the different groups of openings (104) responds in the collimator (102), the individual crystal elements (112, 114) simultaneously respond to the radiation, the focal axes of the passage channels with each other Cut at an acute angle and the measuring head (100) in this way via a radiation source is led away that the electromagnetic response of the one crystal element (112) discreet and staggered in time from the electromagnetic response of another Crystal element (114) is. 2. Scintigraph according to claim 1, characterized in that g e k e II n -z e i c h n e t that each crystal element (112, 114) is followed by a photomultiplier tube is the the electromagnetic generated by the crystal elements (112, 114) Receives signals, connectors, the output values of the photomultiplier tubes to an oscilliographic display device, the oscillographic Display device the output values of the photomultiplier tubes in each other separate channels and the information received on the separate channels reproduced separately and sharply at the same time. 3. Scintigraph according to claim 1, g e k e n n z e i c h -n e t through several photomultiplier tubes, each on the electromagnetic signals only one of the crystal elements (112, 114) respond, but simultaneously with the other multiplier tubes, a multi-channel analog-to-digital converter from each of which one channel is connected to only one photomultiplier tube, a common one Computers with multiple groups of data channels, each group with only one Channel of the analog-to-digital converter is connected, data handling devices in the Computer for shaping the supplied data, storage devices for separate Saving the formed data from the individual groups of the data channels and a Presentation reproducing device for the results of the formed data. 4. scintigraph according to claim 3, characterized in that g e k e n n -z e i c h n e t that the data reproduction display device uses an oscilloscope for simultaneous two-dimensional display of the data results from different data channel groups has, wherein the oscilloscope is also able to mathematical, graphic To display representations of the formed data from different data channel groups, and that Means for summarizing the information data from various Data channel groups to a single representation reproducing the depth calculation available. 5. Method of mapping the local distribution of radioactive substances in the organism, by the fact that gamma radiation on a, a path crossing a plane is scanned, a first definite part of Radiation from recording is shielded from another area of radiation the simultaneous recording is shielded from the radiation by a certain Section of the shield is passed through channels at the same time, another part the radiation is directed through another section of the shield, the alignment has a common point of intersection in a focal plane from which selected, separately conducted directed radiations simultaneous and separate, Electromagnetic response values generated in crystals are obtained in separate Channels for themselves and at the same time the separately determined electromagnetic Signals are counted by photomultiplier, which occur in ncontinuous form electromagnetic anal signals are converted into discrete, pulsating digital signals, in separate channels and simultaneously with the counting by the photomultiplier, the digital data are sent separately to computer databases, the data be shaped by data processing in the computer and at the same time the obtained Counting and measuring results separately and clearly delimited for the different signal flow channels as the result of the scanner scan. 6. Scintigraph for recording the distribution of radioactive substances in a patient's body and to represent the distribution in mathematical terms and graphic form, given by a recording head with a Collimator, a crystal element on top of the collimator in the head, wherein the collimator is relatively one for the passage of gamma rays impermeable lead shield contains a group of passageways (104) in the collimator for the gamma rays whose axes point to a point below the Collimator (102) are directed, the point being on the focal axis of each Channel lies and within the focal plane in which the radiation through the measuring head should be recorded and all focal axes of the channels to each other at an acute angle cut while the crystal emits a light signal, depending on the through gamma radiation passing through the group of channels, furthermore through a photo intensifier tube, which emits a signal corresponding to the light signal emitted by the crystal, a linear preamplifier (323), which is a signal from the photo amplifier tube (313) outputs corresponding electrical signal, a linear amplifier (325), which is a Signal generated according to the signal of the linear preamplifier (323), an energy discriminator (327), the signals within predetermined amplitude limits corresponding to the from Linear amplifier (325) emits generated signals, a machine-wired computer interface unit, which emits a signal in a form in which it can be received by a central processing unit (495) can be processed, the signal being the output from the energy discriminator (327) Signal corresponds, while the interface unit (329) a L. '? P 'l.et F' tnen buffer output L, an address selector (40), an interrupt function unit, a counter (464) and a byte operating circuit (472) and the central processing computer (495) a data bus (478), an accumulator (498) and a memory device wherein the interface level buffer memory sends a request signal to the data bus (478) as a function of the signals emitted by the energy discriminator (327) sends out, the data bus (478) depending on the request signal an execution signal outputs to the buffer output (484), the interrupt function unit outputs the address selector (470) is ready to work on a signal coming from the counter (464), the central process data bus (478) to a data field (492) in the memory array Able to transfer data without it having passed through the accumulator (498) the accumulator information from the data field (492) based on commands capable of receiving a program stored in the memory device, whereby Data determined by the radiation passing through the collimator in the data field (492) of the storage device can be stored, unaffected by simultaneously running operations of the central process computer, which by its accumulator are processed. 7. The device according to claim 1, characterized in that g e k e n n -z e i c h n e t that an array of photo intensifier tubes is provided, which on from the Crystal elements (315, 316) address generated electromagnetic signals, several Linear preamplifier (323, 324) one each electrical signal as a function from the photo amplifier tubes generate multiple linear amplifiers (325, 326) in dependence emit signals from the electrical signals of the linear preamplifiers (323, 324), several energy discriminators (327, 328) signals within certain amplitude limits depending on the signals of the linear amplifier (325, 326) generate and computer interface units (329, 330) emit signals in a form that is stored in the central processing unit of a digital computer are processable, each of these signals being determined by the signals that issued by the various energy discriminators (327, 328). 8. Apparatus according to claim 1, 2 and 7, g e k e n n -z e i c h n e t by a device for calculating and representing the distribution in mathematical terms and graphic form depending on the data provided by the computer interface unit (329, 330) given signals. 9. Apparatus according to claim 7, characterized in that g e k e n n -z e i c h n e t that the computer interface unit has a level buffer memory (468), a buffer output (484), an address selector (470), an interrupt function device, a Counter (464) and a byte operating circuit, the central processing computer (495) a data bus (478), an accumulator (498) and a memory arrangement the interface level buffer (468) sends an interrogation signal to the data bus (478) emits, depending on the sent out by the energy discriminator (327, 328) o signals, the data bus (478) depending on the query signal on the address selector (470) transmits an execution signal to the buffer output (484), which Interrupting Function Unit the address selector (470) ready for operation depending on a signal received from the counter (464) switches the data bus (478) to a data field (492) in the memory array The accumulator transfers data that did not go through the accumulator (498) (498) in response to instructions from a program stored in the memory arrangement extracts information from the data field (492), thereby creating data transmitted by the radiation are determined which have passed through the collimator (320), the data field (492) of the storage device unaffected by the same time in the central processing computer (495) running operations can be saved which operations are carried out by the accumulator (498) of the central processing computer can be determined. 10. The device according to claim 9, characterized in that g e k e n n -z e i c h n e t that in the memory array (492) an area for derived computations is present, the central process computer of data stored in the data field in Calculations as a function of a program stored in the memory arrangement carries out and the execution of the calculations by the central process computer and storing the results in the computation field is one of the processes running at the same time. 11.Vorrichtung according to claim 9, g e k e n n z e i c h -n e t through a viewport (504) in the memory array, the central processing computer Representation information is calculated from data stored in the data field and the stores display information obtained therefrom in the display field (504), addicted by a program contained in the memory arrangement, further by an oscilloscope imaging device (505) connected to the central processing computer is connected and the display information of the display field (504) in Maps depending on a program stored in the memory arrangement, wherein the central processing computer calculates and stores the display information and mapping the presentation information on the display device (505) to the concurrently operations in progress. 12. The device according to claim 11, characterized in that g e k e n n -z e i c h ne t that the display field is divided into individual fields and each individual field corresponds to the display information of an associated individual field of the data field, whose data in the individual field is derived from the signals of one of the energy discriminators is that the oscilloscope display device separately the imaging information of each Individual fields of the mapping field (504) reproduces a field in the memory unit is provided for derived calculations, the central process computer calculations from the data stored in the data field, depending on one in the memory device stored program, the field of the derived calculations divided into subfields is where each of the subfields derive computations for a corresponding one Subfield of the data field, the data in the subfield of the Signals of one of the energy discriminators (327, 328) are derived while to performing calculations for the other concurrent processes through the central process computer and saving the results belongs in the derived calculation field. 13. The device according to claim 2, characterized in that g e k e n n -z e i c h n e t that an optical viewer with two lenses with mutually parallel optical Axes that are directed towards parallel but separate images, which are imaged on the oscilloscope display device (505), each image corresponds to another separate channel.