WO2011082738A1

WO2011082738A1 - Cassette for a storage film, storage film for use with said cassette, device for reading a storage film, examination device comprising said type of cassette and method for capturing panographic images

Info

Publication number: WO2011082738A1
Application number: PCT/EP2010/007206
Authority: WO
Inventors: Michael Thoms
Original assignee: DüRR DENTAL AG
Priority date: 2009-12-21
Filing date: 2010-11-27
Publication date: 2011-07-14
Also published as: DE102009060020A1

Abstract

The invention relates to a cassette (14) for panography which is can receive a plurality of storage films (46, 48, 50) in the shape adapted to the geometry of the jaw. A carrier plate (36) of the cassette (14) can be individually adapted, elastically or plastically, to the shape of the jaw which is to be examined.

Description

Cassette for a storage film,

Memory sheet for use with such

Apparatus for reading a storage film, examination apparatus with such a cassette and method for taking panographic images

The invention relates to a cassette for a storage film, a storage film for use in such a cassette, a device for reading such a storage film and an examination device which operates with such a cassette and a storage film.

In dentistry are mainly two types of

Radiographs made, namely intraoral images and panoramic images. In the panoramic images, the exposure of the image carrier (classic X-ray film or storage film) is carried out through the skull, whereby it is ensured by the imaging geometry that only the areas of interest of the skull,

namely the jaw, being sharply imaged while

the other parts of the skull lead to a homogeneous surface. However, since the X-rays traverse the skull entirely, more X-radiation is absorbed by the body than in an intraoral recording, in which the X-ray only the one to be examined

Cross the jaw area.

It was therefore tried in earlier years, in the

Inside of the mouth to arrange a small X-ray source, which radiates into a (relative to the Antikathode) rear half-space (ie to the back of the two jaws), then an extensive X-ray film is placed around the outside of the jaw, which is simultaneously exposed at all points by the X-rays emitted backwards. This type of X-ray imaging, known as panography, makes it possible to record the entire upper jaw and lower jaw with one image.

This method has increasingly disappeared since 1980 et seq., Since the x-ray tubes inserted into the mouth had an operating voltage of only about 55 kV with the beam current at 1 mA. Under such operating conditions, one has a high portion of the spectrum of the tube at low energies, which ultimately causes the skin to over-dose

is charged.

A general disadvantage of the panography method is that the image is heavily distorted due to the use of a point light source, so that the assessment of the

X-ray image requires special experience. On the other hand, it was advantageous in the panography that the image compared with that obtained with conventional panoramic images, with the same footage or

Sheet material was sharper as long as magnification factors below 1.5 were used.

Meanwhile, x-ray sources that can be inserted into the mouth have been developed that can be used in the range between 50 and 70 kV with currents of 0.1 mA and smaller. With such X-ray tubes, in which the spectral component is reduced at low energies, the burden on the skin can now be kept smaller. The focal spot is less than 0.1 mm. Typical exposure times are between 0.1 and 5 sec. This ultimately allows a resolution of 5 line pairs per mm, with which caries is detectable by Rötgenuntersuchung. The present invention seeks to provide a cassette which allows for the easy use of exposable pieces of material for the purposes of panography, in such a way that the exposable piece of material is curved approximately in accordance with the course of the jaw.

The invention is also intended to be a storage film

be specified for use in a

such cassette is particularly suitable.

By the invention, a device is also to be specified, with which memory films in the

Cassette invention are used, can be read.

The invention is also intended to specify a panography examination device.

These objects are achieved by

a cassette with the specified in claim 1

Characteristics, by a storage film having the features according to claim 26, by a read-out device

according to claim 32 and an examination device according to claim 39.

Advantageous developments of the invention are the subject of dependent claims.

In the case of a cassette according to claim 2, its basic shape assumed in the unloaded state corresponds roughly the course of a jaw. So there are only minor adjustments to the geometry of each individual individual jaw to be recorded. The development of the invention according to claim 3 allows to easily take into account a large number of jaw shapes.

In the case of a cassette according to claim 4, the support part remains after adaptation deformation in the respectively selected geometry.

In a cassette according to claim 5, the support member can be repeatedly adapted to different jaw shapes.

Even with the development of the invention according to claim 6, it is possible to adapt a support member specifically to the shape of a jaw. A cassette

with a support member according to claim 6 is characterized by a particularly long life.

A certain elastic bias of the holding part results already from the fact that the exposable material pieces used in the holding part have their own elastic flexibility, which may well be significant, especially if one places a plurality of such exposable material pieces one behind the other.

With the development of the invention according to claim 7, a geometry adjustment of the support member for the exposable material piece is obtained in a simple and reproducible manner. In this case, the specified in claim 7 locking device is characterized by a particularly simple mechanical construction.

In a strut-locking device according to claim 8, one can bring about the locking in a simple manner. It only needs a single clamping handle to be operated.

In a cassette according to claim 9, the respectively set geometry of the support member can be easily characterized by a few numbers. These can be z. B. are entered into a computer to inform them about the respectively set shape of the support member. The development of the invention according to claim 10 makes it possible to easily take into account the fact that jaws typically have a more curved front portion and a less curved lateral portion. This results automatically by the different bendability of the various sections of the support member that they are deformed differently when exercising a force acting on them alike. In this case, in a cassette according to claim 11, a continuous change in the curvature of the support member is obtained.

In the case of a cassette according to claim 12, the actual support part can be designed as a plate of constant thickness and the different bendability of the different plate sections obtained by placing on the plate a reinforcing rib whose cross section changes. The development of the invention according to claim 13 is in view of a simple releasable connection between

Material piece and support part of advantage. It is obtained with the development of the invention according to claim 14, a forced positioning of the exposable piece of material along its entire longitudinal edge, and by moving the retaining strip, the exposable piece of material can be easily released.

The development of the invention according to claim 15

is advantageous in view of that by the

Support bar no additional bending stiffness is caused.

In a cassette according to claim 17, the retaining strip can be twisted under elastic deformation so that the exposable piece of material is released from it. Alternatively or additionally, the retaining strip may additionally comprise pivotable retaining lugs, which are movable against spring force in a position releasing the storage film. The development of the invention according to claim 19 is advantageous in terms of making the support member as a cheap wearing part, possibly also as a disposable item. The further development of the invention according to claim 20 makes it possible to insert the tube-shaped part of an intraorally positionable X-ray source containing the anticathode through the support part. In this way, the carrying part, the exposable piece of material carried by it and the X-ray source become one unit connected .

According to claim 21 obtained in a simple manner, a light-tight envelope for the exposable piece of material.

In this case, the development of the invention according to claim 22 in terms of low cost of the protective case of advantage. If the protective cover is closed in a light-tight manner as specified in claim 23, then this closure can also be carried out in a dental practice or at another place of use without major skills. In a cassette according to claim 24, a hygiene part is connected to the protective cover of the cassette, which surrounds the intraoral positionable housing part of the X-ray source, when the unit formed by this housing part and the cassette is positioned on the patient's jaw.

The development of the invention according to claim 25 makes it possible to customize each cartridge. This individualisation may relate to the number and type of exposable pieces of material contained in the cassette, but in particular also relates to the geometry of the supporting part used for panography. The corresponding data can be stored in a memory and used by a when reading the latent image of the exposable material piece

Calculator can be retrieved based on the identification to make correction calculations, evaluations and presentation implementations on the captured image. The development of the invention according to claim 26 equips it to expose different pieces of material at the same time. In this case, it is then possible to use pieces of material of different resolution and / or sensitivity and thus to produce panorama images with a single exposure, which are adapted to different circumstances of the structure to be examined.

The development of the invention according to claim 27

is in view of the advantage that the geometry of the piece of material, which for recording

is used when exposing and reading out

can be chosen the same. This allows, in principle, to install the piece of material firmly into the cassette and to read it lying in the cassette.

Only when replacing a worn piece of material with a new one does the piece of material need to be removed from the cassette and a new piece of material reinserted into it. The fact that in normal operation, the piece of material remains in the cassette, is

its wear reduced.

If a storage film according to claim 28 is used in conjunction with a cassette according to the invention, then the intraorally positionable tubular portion of the x-ray source can simply be inserted through the storage film.

In this case, it allows the development of the invention according to claim 29, to insert the exposable piece of material laterally in the support member. Such introduction of the piece of material is particularly simple, since the piece of material automatically moves into the desired geometry with advancing in the holding part. The slot enabling this is at the same height, in which also the intraorally positionable rohrformige housing part of the X-ray source is located. Since the latter must lie between the teeth of the jaw, there are usually no teeth or jaw sections to be imaged in the region of the slot provided according to claim 29.

Even with the development of the invention according to claim 30, it is possible to bring the exposable piece of material by moving into the desired recording position, wherein only in the region of the passage opening for the X-ray source is no photosensitive material.

With the development of the invention according to claim 31 ensures that there is no gap at the joint hiss the film segments.

In a device according to claim 32, the

Detecting the geometry of the cassette by machine.

In a device according to claim 33 one can visually evaluate the respective curvature of the support member in a simple manner. The recording of the shape of the support member by a camera is preferably carried out after reading the exposable piece of material or after its removal. The shape of the supporting part can be removed after removing the

Protective cover particularly simple and accurate.

It is again the use of a camera, as in

Claim 33 specified, particularly advantageous because their image can be evaluated very easily on curved structures.

A similar advantage is obtained according to claim 34 with respect to the machine reading of a cassette identifying identification.

With regard to a simple implementation of the panography, it is particularly advantageous if the reading of the exposable material piece takes place in the same geometry of the piece of material as its exposure. Since the exposable piece of material is adapted to the shape of the jaw, the use of a single scan head with rotating readout beam would be very different

Reading conditions in the different areas of the

Material piece received.

With the development of the invention according to claim 35 is achieved that in different areas of the exposable piece of material has substantially the same read-out conditions, although the geometry of the exposed piece of material is not cylindrical.

In a device according to claim 36 one has a very

good resolution with a total of still less number of scan heads used.

With the development of the invention according to claim 37 it is achieved that the latent image is read out under essentially the same amount of the readout light at the different pixels.

If, instead, one wishes to work with a constant sampling angular velocity, one can alternatively also choose the intensities of the readout light sources of the various

Adapt scan heads so that they are path-dependent, if necessary, so that each pixel of the latent image is read out with the same dose. A device according to claim 38 is also characterized easy handling. There are no significant mechanical adjustments to make.

With the development of the invention according to claim 39 is achieved that there is no crosstalk of fluorescent light when working the different scan heads.

A device according to claim 40 also makes it possible to adapt a material piece, which is better adapted to the course of a jaw in its geometry than partially cylindrical geometry, with largely the same read-out conditions for the different pixels of the jaw Material - read piece. Thus one obtains in a simple way a successive structure of the different image lines or image columns.

In the case of an apparatus according to claim 41, only one single scan head is needed, which is placed at different locations, depending on which region of the exposed material piece is read out. This switching of the scan head in different working positions according to claim 41 only a few positions.

An apparatus according to claim 42 makes it possible to record a structure to be examined at different levels and under different projection conditions. The respective conditions are determined by the

Marked the Aufbisseinrichtung in a simple manner.

Sometimes it is advantageous, together with a larger format panoramic image, to make a small-format intraoral image. This can be done with nem device according to claim 43 in a very simple manner.

The preferred device according to claim 44 makes it possible to apply only parts of the rear half-space with X-rays in which a recording is desired.

Through different caps and different

Putting caps in different axial

Position and different angular position can be applied to the each with X-rays

Set area easily.

In an examination apparatus according to claim 45, the photosensitive material piece may always be in the

remain the same curved shape. This fatigue fractures but also wear marks are

avoided the surface.

In a device according to claim 46 designed the

Capturing panographical images is particularly easy, since the scanning of the latent image of a memory film piece can take place directly at the location of the recording. All you have to do is to move the imaging plate used for recording over the geometry of a geometry in which it was located during the recording, over a reading gap of the scanner. This can also be done by moving the cassette carrying the storage film directly over the reading gap of the scanner. Where it is not possible to arrange a holding station comprising the cassette and a scanning station axially behind one another, a transport device can be provided according to claim 47 which brings the cassette from the receiving position to the scanning unit in a defined manner. Such a transport direction may include, for example, a linearly movable carriage or a pivoting linkage arrangement.

The method given in claim 48 makes it possible to produce panographic images corresponding to different layers of the structure to be examined.

The same advantage is obtained by the method specified in claim 49.

With the development of the invention according to claim 50 it is achieved that with good cost / benefit ratio the respective properties of the receiving device and the scanning device of the used .Untersuchungs- device are used.

The procedure specified in claim 51 facilitates

an operation of the examination device and avoids

Failure to make settings that would otherwise be present on the examiner to take into account special

Properties of the used storage film must be made. With the method specified in claim 52 images are obtained, which are particularly easy to visually assess the viewer.

The invention will be explained below with reference to FIG

the drawing with reference to the embodiments closer

explained. In this show:

Figure 1 is a partially sectioned plan view of a

Panography examination device with an intraoral positionable X-ray source and a cartridge for storage foils; Figure 2 is a plan view of the unit shown in Figure 1 from the patient side;

Figure 3 is an enlarged plan view of a section of a retaining strip, which is part of a storage film support member of the examination apparatus of Figure 1;

FIG. 4 is a plan view of a modified embodiment of a storage film support member together with an intraorally positionable X-ray source;

FIG. 5 shows a schematic block diagram of a device for reading out a panographic imaging film and for processing the read-out image as a function of the geometry of the imaging film;

Figure 6 is a schematic plan view of a device for

Reading a memory sheet in the geometry in which it is used for a panography shot;

Figure 7 is a side view of a tubular end portion of an intraorally positionable X-ray source with an attached Blendenkap e;

Figure 8 is a plan view of a modified storage film for use in panography; Figure 9 is a plan view of a further modified Panoramic imaging film consisting of two flush parts,

Figure 10 is a view similar to Figure 9, in which

however, the adjacent sections of composite foil segments overlap;

Figure 11 is a side, partially vertically cut

View of an examination device for making panographical images of a patient's jaw; and

Figure 12 is a Schamtische representation, based on which

converting a panographical image of a jaw into a. Panorama picture is explained.

In FIGS. 1 to 3, a panography examination unit is denoted overall by 10. It comprises an X-ray source 12 and a cassette unit 14, which is detachably mounted on the X-ray source 12.

The X-ray source comprises a housing 16 with a rear cuboid housing section 18 and a slender tubular front housing section 20. In the rear housing section 20 is an electron gun

24, which provides an electron beam 26 which passes centrally through the tubular housing portion 20 and at its end to a

Antikathode 28 hits. When braking the electron beam 26 on and in the Antikathode creates a

Roentgen radiation, as indicated schematically at 30. This is discharged into the rear half space of the Antikathode 28. The material from which the housing section 20 originates. is transparent to X-rays, opaque to visible light, eg a metal with a low atomic number. At 32, a voltage supply for the X-ray source 12 is indicated.

The cassette unit 14 comprises a hub part 34, to which a support plate 36 is laterally and upwardly and downwardly formed. The support plate 36 is in settlement recheckig and the hub portion 34 is located at the center of the rectangle.

Seen from above, the support plate 36 in the unloaded state has the apparent form of Figure 1 shape that comes close to the shape of a human jaw.

Along its upper and lower edges, the support plate 36 is provided with a support rail 38 and 40, respectively, which has a rectangular U-shaped cross-section, as shown in FIG. The retaining rails 38 and 40 each have a base portion 42 which is perpendicular to the main surface of the support plate 36, and a front leg 44 which tapers to the horizontal center plane of the cartridge unit 14 under Einsatzbedin- conditions. This center plane corresponds to the plane of the drawing of FIG. 1.

The distance of the leg 44 from the front of the support plate 36, so the width of the base portion 42 is selected so that three memory foils 46, 48, 50 lying behind each other with their upper and lower ends in the support rails 38, 40 recording. The imaging plates 46, 48, 50 may be in their

Resolution and / or its sensitivity to produce images with different diagnostic value with a single exposure. The storage foils 46, 48 and 50 can also be identical. One then uses the images held in these memory films 46, 48, 50 to compose them pixel by pixel to form an overall image

to get better signal / noise ratio.

In modified retaining rails, the base portion 42 may be smaller or larger, to accommodate fewer or more memory sheets and possibly also absorber sheets. The storage foils 46, 48, 50 each have a central opening 52 which can receive the hub part 34.

As can be seen in FIG. 3, the base sections 42 and the legs 44 are provided with wedge-shaped recesses

54 provided to bend the support rails 38, 40 together with the support plate 36 can.

As can be seen in FIG. 2, the legs 44

further lower recesses 56, between which retaining lugs 58 remain.

The support plate 36 and the support rails 38, 40 are injection-molded from an elastically deformable plastic material, so that the upper edges of the retaining lugs 58 can be pressed under the upper or lower edge of a storage film 46, 48, 50 in order to remove or insert a storage film ,

The cartridge unit 14 further comprises a protective cover, generally designated 60, which is replaced by a back cover. wall 62 and a front wall 64 is formed. Rear wall and front wall are made of a pigmented plastic material, so that the protective cover 60 is sealed against visible light.

As can be seen from Figure 1, have back wall 62 and

Front wall 64 in the region of reduced diameter portions 66, 68 of the hub portion 34 cylindrical protuberances 70, 72 which are press-fitted on the reduced diameter portions 66, 68 are placed. Alternatively, they can also be welded or glued there.

At the edges are rear wall 62 and front wall 64 by longitudinal welds .74, 76 and cross welds

78, 80 connected.

To the hub portion 34, an upper Aufbeißplatte 82 and a lower Aufbeißplatte 84 is formed. In the area of Aufbeißplatten 82, 84 have the rear wall

62 and the front wall 64 corresponding prismatic

Protuberances (not shown) so that the bite plates 82, 84 are located inside the protective cover 60.

The Aufbeissplatten 82, 84 may be provided on its top and / or bottom with visual and / or tactile perceptible markings 85-1, 85-2, etc. In this way it is possible in a patient who

X-ray source 12 to be arranged in different precisely predetermined positions inside the mouth of a patient and set the same relative position between the X-ray source and jaw in different patients. For each of these positions one obtains in the first case an image with slightly different projection conditions, in particular different magnifications. From different such Pictures can then be computationally create layer images. In the second case, one has the same projection geometry in different patients. The tubular housing section 20 of the X-ray source 12 is surrounded by a cylindrical hygienic part 86 which is closed at the free end and which can likewise be pressed onto the hub section 68, shrunk, glued or welded on.

Thus, the examination unit 10 formed by the X-ray source 12 and the cassette unit 14 is enveloped in a light-tight and fluid-tight manner. On the outside of the support plate _ 36 may (as in-. The left half of Figure 1 indicated) a metal rail 88 may be placed, which is made of a metal which can be plastically deformed several times without breaking. Thus, the support plate 36, which is already adapted from home to an average jaw, the respective requirements of an individual jaw bill bearing so bent that the support plate 36 and thus also held by her memory sheets 46, 48, 50 parallel to the jaw outside ,

FIG. 4 shows an alternative possibility of adjusting the geometry of the support plate 36. Components of the examination unit 10 which are not necessary for understanding the adjustment of the geometry of the support plate 36 are omitted in FIG. It is also shown only half of the cassette unit, the other is mirror-perfect.

One recognizes in Figure 4 one on the back of the

Support plate 36 patch stiffening rib 90, whose Cross-section increases with increasing portion of the axis of the X-ray source 12. In the present case, the increase in cross-section is chosen so that it takes place in the direction perpendicular to the main surface of the support plate 36 direction. In addition or instead, an increase in cross-section in the direction perpendicular to the plane of the drawing of FIG. 4 may also be provided.

The stiffening rib 90 is spaced at two

Make bearing openings 92, 94, each of which can receive a pivot pin 96 and 98, which is supported by the end of an actuating rod 100 and 102, respectively. The

Control rod 100 passes through a tendon guide 104, which is provided in a bearing block 108. The bearing block 108 is slidably mounted on a support plate 110 which is mechanically fixed to the hub part 34 (here via the housing of the X-ray source 12).

The bearing block 108 is slotted in its portion located above the support plate 110 in FIG. 4 and thus has two clamping plates, one of which is shown at 112. In the clamping plate 112, a threaded bore 114 is provided, while the upper clamping plate, not shown, has a through hole, which is aligned with the threaded bore 114. In this way, the two clamping plates can be adjusted in their distance by a screw and the adjusting rod 104, which preferably has a rectangular cross-section, clamp between them.

The control rod 102 is guided in a bearing block 116 which rotatably via stub shafts 118 in a

Carriage 120 is mounted, which is displaceable on the support plate 110. The bearing block 116 is again slotted in order to position the actuating rod 102 in the respective locked position to be able to lock.

The adjusting rods 100, 102 each carry a scale 122, which is read on the end face of the associated bearing block 108 or 116.

By the locking device described above, the course of the support plate 36 can be adjusted upon release of the adjusting rods 100, 102 and then fixed in its form by the clamping devices of the two bearing blocks are tightened.

The cross-sectional profile of the reinforcing rib 90 can be used to specify how much the support plate 36 can be adjusted in different areas.

FIG. 5 schematically shows a scanner 124 which can read out the storage foils 46, 48, 50 one after the other.

Image plates comprise a photosensitive layer containing, dispersed in a matrix, phosphor particles provided with color centers. At finished color centers there are local electronic excitation levels that can be activated by X-rays and have long lifetimes ranging from 15 minutes to one hour. If excited such color centers are irradiated with a laser beam which is red in practice, the color centers are raised to a higher excited state and relax therefrom, emitting blue fluorescent light. By photoelectrically registering the fluorescent light of each pixel of the storage film It is thus possible to convert the latent image of the investigation project generated by the X-rays into an electrical image which can be digitally processed and converted. Such conversion allows, in particular, the conversion of the less familiar panography representation into a panorama representation.

In Figure 5, a laser is shown at 126, a

providing fine red laser beam 128. This laser beam is only reproduced schematically

Mirror 130, 132 placed on an axis 134 of the scanner. A deflection prism 136, which deflects the laser beam 128 into a transverse read-out plane, in which it then rotates in accordance with the position of the deflection prism 136, runs around this axis.

The memory film 46, 48 or 50 to be read is placed on a transparent cylinder 138 and moved on it by three drive belts 140, 142, 144 in the axial direction.

The drive belts 140, 142, 144 are mechanically coupled as indicated by dashed lines and are driven by a stepper motor 146 which cooperates with a rotary encoder 148.

To capture the fluorescent light is a large

Diameter-comprising photo multiplier 156 which is surrounded by an annular mirror 158. Above the

Drawing plane of Figure 5 is to think another mirror, which also fills the clear cross-section of the cylinder 138.

The output of photomultiplier 156 is applied via an amplifier 160 to an input of a process computer 162 given.

The process computer 162 receives at another input the signal of the rotary encoder 148 and the signal of a further rotary encoder 164 which is coupled to an electric motor 166 which rotates the deflection prism 136 at high frequency.

The process computer 162 also controls the stepper motor 146 and the electric motor 166.

Further, the process computer 162 controls an electro-optic shutter 168 to rapidly turn on and off the light emitted by the laser 126, as described in greater detail below.

A camera 170 is provided to detect the respectively set geometry of the support plate 36 and to report it to the process computer 162.

A mark reader 172 serves to read a mark 174 characterizing the cassette unit 14. Under an identifier which corresponds to the bar code of the mark 174, data are stored in the process computer 162 which indicate the number and type of the imaging plates used. If attenuator sheets lying between the storage foils are used during recording, the corresponding data are likewise stored under the identifier corresponding to the mark.

On the output side, the process computer 162 is connected in a controlled manner to a high-voltage device 176, which provides the operating voltage necessary for driving the photomultiplier 156. To enter data, the process computer 162 is connected to a keypad 178.

An output of data and the output of control messages is possible via a monitor 180 connected to the process computer 162.

For storing read-out images, the process computer 162 is connected to a mass storage 182, and a printer 184 can be used to output images, record logs, and so on.

In the case of the read-out device shown in FIG. 5, the shape of the memory film to be read out is adapted to the shape of the transparent cylinder 138. The laser beam 128 thus impinges on all pixels vertically, and the geometric ratios of the readout are constant across the image.

For some applications, it would now be advantageous if one could read the memory film in the same geometry in which it was exposed.

FIG. 6 shows a corresponding read-out device. Components already described with reference to the preceding drawings are again given the same reference numerals, although they differ in detail.

Some components that are not necessary for understanding the readout device of Figure 6 are also omitted. FIG. 6 shows a storage foil 46 which permanent or by placement on a support plate

has a geometry adapted to the shape of a particular jaw. The overall geometry is obviously not circular. But you can put the readout surface of several, here three, partially cylindrical surfaces.

A first part-cylindrical surface extends over an angular range Wl, which is symmetrical to the longitudinal center plane of the storage film 46. A second

Angle range W2 follows the end of the angular range W1 on the right in the drawing

and extends to the one free end of the

Memory film 46. Symmetrical to the angular range W2

a third angle range W3 is provided which extends from the left-hand end of the angular range W1 in the drawing to the free end on the left

Memory sheet 46 extends:

The angular ranges W1, W2 and W3 correspond to bending axes 134-1, 134-2, 143-3.

A deflecting prism 136 - 1, 136 - 2 and 136 - 3 is now provided on each of these axes of curvature, which directs a laser beam 128 - 1, 128 - 2 and 128 - 3 essentially perpendicular to the associated subregion of the storage film 146. The laser beams 128-1, 128-2 and 128-3 are generated by lasers 126-1, 126-2 and 126-3 and mirrored 130-1, 130-2 and 130-3 and 132-1, 132-2 and 132-3 to the respective axle.

For rotating the deflecting prisms 136-1, 136-2 and 136-3, electric motors 166-1, 166-2 and 166-3 provided with resolvers 164-1, 164-2 and 164-3 are provided. The interconnection of the various lasers, drive motors for the deflection prisms and resolver is analogous as explained above in connection with Figure 5 in detail.

The control is roughly speaking in detail as follows:

The electric motors 166-1, 166-2 and 166-3 are specially synchronized with each other. Roughly speaking, the product of the angular velocity of the deflection prism and the distance of the prism axis from the associated region of the storage film is constant. This means that the laser beams 128-1, 128-2 and 128-3

be guided over the storage film 46 at the same web speed. Only one of the laser beams 128-1, 128-2 and 128-3 is active at any given time

corresponding control of the electronic shutters 168-1, 168-2 and 168-3 by the process computer 62 is ensured.

For the present exemplary embodiment, it is assumed that the laser beam 128-3 is initially activated for scanning a line of the storage film 46

from the moment he arrives

on the left end of the storage film 46 meets up

at the moment when the end of the angular range W3 is reached. This is monitored via the resolver 164-3.

As soon as the laser beam 128-1 subsequently reaches the left end of the angular range W1, which is detected from the output signal of the resolver 164-1, the laser beam 128-1 becomes active by opening its electronic shutter 268-1 and scans the angular range W1 from left to the right end. Then, the laser beam 128-1 is turned off by closing its shutter 168-1. As soon as the deflecting prism 130-2 reaches the position in which the laser beam 128-2 lies at the upper end of the angle range 2 in the drawing, the electronic shutter 168-2 is opened and the remaining part of the scanning line is deflected by the laser beam 128-2 - drive.

It can be seen that, in the manner described above, the storage film 46 is read out under substantially constant conditions, both as regards the angle of incidence and as regards the dose of read-out light.

To detect the fluorescent light are now three

Fotomultiplier 156-1, 156-2 and 156-3 provided, the same amplifier (not shown) with the

Process computer 152 are connected. The outputs of the three photomultipliers 156 are summed. The photomultipliers 156 are embedded in a mirror plate 158, and this again faces (against the drawing plane of Figure 6) a fully mirrored plate.

It can be seen that in this way a high-resolution image can also be obtained under read-out conditions which come close to the exposure conditions.

In the exemplary embodiment shown by solid lines in FIG. 6, three scan heads synchronized by the process computer 162 are used, each comprising a laser and a deflection prism. Alternatively, as shown dashed in FIG. 6, it is also possible to use only a single scan head, which is successively placed on the three axes of curvature 134-1, 134-2 and 134-3. For this you can see the parts of the

Set scan head on a carriage 186, which is then adjustable by an X-drive 188 and a Y-drive 190

In this case, then the angle ranges Wl, W2 and W3 are scanned for all axial positions, and then the carriage 186 is moved to the next working position. The corresponding partial images are then joined together electronically to form an overall picture.

For some applications, it is not necessary to completely x-ray the full arches of the mandible and maxilla. For partial images of the mandibular arches, a shielding sleeve can be placed on the intraorally positionable tubular housing section 20 of the X-ray source

192 on. By the axial extent of which one can vary the opening angle of the X-ray beam generated in the back space. If one provides the shielding sleeve 192 with a cutout 194, one can additionally X-ray certain lateral sections of the mandibular arch.

In the panography apparatus described above, the storage foils 46, 46, 50 were first inserted into the cassette unit 14, with the openings 52 provided in them being pushed axially over the hub portion 34 and, if necessary, the picking plates 82, 84. This pushing is done in the axial direction of the housing portion 20 until the memory foils 46, 46, 50 with elastic deformation of the retaining lugs 58 finally lent in the support rails 38, 40 engage. For some applications, it is advantageous if the storage film 46, 46, 50 can be inserted from the side into the cassette unit 40.

For this purpose, according to FIG. 8, a slot-shaped opening 52 can be provided in the storage film for its one edge. Of course, no X-ray image can then be taken in the region of the opening 52, which is acceptable for many applications, since the hub part 34 in any case spaces the teeth of the lower jaw and the upper jaw.

If you want to take advantage of the lateral insertion of the imaging plates 46, 46, 50, but still produce a full panography image, you can according to FIG

9, the storage foil 46 into two segments 46A and 46B

subdivide, which abut at the center of the storage film. FIG. 10 likewise shows a storage film 46

two segments 46 and 46B. These two segments look similar to the memory sheet of Figure 8,

However, the slot 52 is significantly shorter, and it uses two 180 ° against each other twisted Speicherfo- lien to provide a continuous photosensitive surface, which has a receiving opening 52 for the

Hub part 34 of the X-ray source 12 contains.

The segments 46 and 48 can after a horizontal

Separate then spatially separated a scanner be retracted to read the images held by them. These are then assembled electronically bumpless later. If you use a scanner according to DE 199 42 211 AI this purpose be mounted on a vertically movable table with two movable in the circumferential direction of the cylinder Auflägeflächen, which then the film segments in the predetermined Abastgeometrie on a

Readout gap of the scanner passes.

Modifications of the above-described exemplary embodiments may include:

The cassette specifies a (partially) cylindrical shape of the storage film. The imaging plates can thus be read in their exposure geometry with a normal scanner having a cylindrical film support. If desired, a representation conversion into the panographic representation or a panoramic representation taking into account the otherwise determined jaw geometry can be carried out mathematically by means of point coordinate transformation. The corresponding transformation data may be e.g. be determined experimentally on a phantom head.

An X-ray source with mouth-insertable, slim housing portion 20 may also be used for normal intra-oral recordings. A tube is then placed on the housing section 20, from which the x-ray beam exits laterally in a collimated manner. Due to the small diameter of the housing portion 20, it is possible to place the X-ray source up to 7 times closer to the jaw than a conventional X-ray source for intraoral recordings. As described above, unnecessary parts of the X-ray light can be masked out by an absorbent cap with a correspondingly designed window.

Instead of a light-tight protective cover 60 for the cassette, a light-tight protection vorzehen cover. This can also comprise at the edge of the opening 52 welded film layers. For many applications, however, is the penetration of a smaller amount

Daylight at the edge of the opening 52 also tolerable. A so wrapped memory film is then just as used in the support member, as described above for a naked storage film.

Overall, the examination device described above makes it possible to produce x-ray images of good quality with low radiation exposure of the patient from extended areas of the jaw, and in a cost-effective manner, since the examination device, unlike a panoramic device, does not require complex and precise guidance mechanics. The

Examination equipment also requires no structural measures on the room in which it is used.

In FIG. 11, an examination device for producing panographic images of the pines of a patient is designated as a whole by 200. The examination device

consists of a generally designated 202 recording part and a total of 204 designated reading part. The recording part 202 has substantially the same structure as that for the embodiments of FIGS

Figures 1 to 8 described. It does not need it

to be described in more detail. For the components, the reference numbers used above are used again.

The support plate 36, which carries a storage film 46, but is now rigid and exactly part-cylindrical. It surrounds the face of a patient 206

under all-sided distance such that the support plate 36 can be freely moved over the patient's head.

For this purpose, the support plate 36 has four eyes, two of which are shown at 208 and 210 in Figure 11. Of these, 208 and 210 threaded sleeves are used in the eyes, which work together with a threaded spindle 216. The latter is driven by a (electric) motor 146 with resolver 148, which is supported by a base plate 220 of the examination device. The two bearing eyes to be considered in front of the drawing plane of FIG

Sliding bushing provided and run on a front of the plane to thinking guide rod, which is arranged similar to the threaded spindle 216, but has no thread.

After extracting the X-ray source 12 from the hub 34 can then be moved by energizing the motor 146, the support plate 36 in the vertical direction. The read-out part 204 is constructed similarly as shown in FIG. Since the read-out part 204 according to FIG. 11 is intended only for reading out a storage film 46 which extends over an angle of approximately 180 °, the circumferential extension of the housing 138 also needs to be only 180 °. Accordingly, the axis 134, on which the deflecting prism 136 (shown simply as a deflection mirror) rotates, moved to the edge of the housing. In the peripheral wall of the housing 138 is a narrow read-out slot 222, which is provided on the inside with bevels 224, 266.

The entire interior of the housing 138 is provided with a

Layer 228 occupies which laser light is absorbed and Fluorescence light, which is triggered by the laser light in the storage film 46, reflected. In this way, the fluorescent light enters the photomultiplier 156 directly or via one or more reflections.

To read the memory sheet 46 only by energizing the electric motor 146, the support plate 136 must be moved quickly against the reading gap 222, then what the further Aufwär sbewegung the support plate 36 is slower, as is desired in view of the desired scan speed.

The moving of the storage film 46 via the read gap 222 is carried out without contact under a small amount of play, so that no grinding marks are produced on the storage film 46 even after a long period of use.

On the underside of the housing 138, a circular arcuate extinguishing lamp 230 may be placed, which frees the storage film 46 of residual images when the storage film is moved together with the support plate 36 in Figure 11 down to make a new recording.

Alternatively, one can also remove the erased storage film (with or without a support plate) and replace it with a storage film having other properties (e.g., size, sensitivity, resolution) (again with or without a support plate).

On the way down, the storage film can then be protected by an attached cap 232 against daylight, which is automatically stripped off when driving up again in the read-out part 204, as indicated by dashed lines in Figure 11.

Figure 12 shows schematically how to convert

a panography image, which was obtained with the examination device according to FIG. 11, into

Panoramic image can make.

A pixel B of the panography image (in the receiving surface A, in the embodiment considered here partially cylindrically curved storage film) is connected by a line L with a point R, which represents the X-ray source 12 with a substantially spherical characteristic. Now one looks for the intersection of this line

a simple curved surface F, which is adapted to the course of the jaw in the cross-sectional contour. Using a representation of this area (whether in tabular or closed form) and the line L between the pixel B and the location of the X-ray source R can then obtain that point P, which would have been obtained in a panoramic image (in this case would be to be imaged structure with a

substantially horizontal X-ray beam has been exposed).

Claims

claims

1. Cartridge for an Exposable Marterial Piece (46,

48, 50), with an at least partially permeable to X-ray and visible light impermeable protective cover (60) and with a support member (36) for the piece of material (46, 48, 50), characterized in that the support member (36) is curved ,

2. Cassette according to claim 2, characterized in that

the support part (36) is curved in an unloaded state symmetrically to a median plane.

3. Cassette according to claim 1 or 2, characterized in that the supporting part (36) has a base portion

(42) and two adjoining these leg portions (44), wherein the base portion (42) and the leg portions (44) have different curvature.

4. Cassette according to one of claims 1 to 3, characterized

characterized in that at least one of the sections

(42, 44) of the support member (36) is plastically deformable.

5. A cassette according to claim 4, characterized gekennzeichend,

in that at least one deformable section (42,

44) of the support member (36) is repeatedly deformable.

6. Cassette according to one of claims 1 to 5, characterized

in that the support part (36) has at least one section which is elastically deformable or flexible and by a locking device (100 to 118) is fixable in the deformed shape.

7. Cassette according to claim 6, characterized

in that the locking device has at least one length-adjustable strut (100, 102) which

on a support part (110) of the support member (36) is supported and at a predetermined point (92, 94) of the support member (36) engages. 8. Cassette according to claim 7, characterized

that the strut (100, 102) via a rotatable

Clamping head (116) or a clampable cutting edge bearing

(104) can be locked on the support part (110). 9. Cassette according to claim 7 or 8, characterized in that the strut (100, 102) carries a scale (122) which is supported by a support member (110)

Brand works together. 10. A cassette according to any one of claims 6 to 9, characterized

in that the support part (36) has at least two successive sections whose

Flexibility is different. 11. Cassette according to claim 10, characterized in that

the support part (36) has at least one area

has, in which the flexibility changes continuously. 12. A cassette according to claim 11, characterized in that

in that the continuous change of the bendability is obtained via an attached stiffening rib (90) whose cross-section and / or area moment of inertia changes in the longitudinal direction of the stiffening rib.

13. Cassette according to one of claims 1 to 9, characterized in that the supporting part (36) has a

Material piece (46, 48, 50) covering the support wall (36) and at least one with an edge of the piece of material (46, 48, 50) cooperating support rail (38, 40), preferably two opposite edges of the material piece (46, 48, 50 ) has cooperating support rails (38, 40). 14. A cassette according to claim 13, characterized in that the holding rails (38, 40) engage over the associated edges of the piece of material (46, 48, 50).

15. Cassette according to claim 13 or 14, characterized in that the holding rails (38, 40) are provided with bending recesses (54).

16. A cassette according to any one of claims 13 to 15, characterized in that the holding rails (38, 40) are formed with successive spaced retaining lugs (58).

17. A cassette according to any one of claims 13 to 16, characterized in that the retaining rails (38, 40) are made of elastically deformable material.

18. Cassette according to one of claims 13 to 17, characterized in that the retaining rails (38, 40) comprise at least one pivotable retaining lug (58) which resiliently in a the associated edge of the material - piece (46, 48, 50) cross Position are biased.

19. A cassette according to any one of claims 1 to 18, characterized in that the supporting part (36) consists of a Plastic material is made.

20. Cassette according to one of claims 1 to 19, characterized in that the supporting part (36) has a preferably centrally arranged visible light impermeable hub part (34).

21. A cassette according to claim 20, characterized in that the hub part (34) light-tight with a front wall (64) and a rear wall (62) of the protective cover

(60) is connected.

22. A cassette according to claim 21, characterized in that the front wall (64) and the rear wall (62) are formed by prigmented and / or vapor-deposited and / or coated film sections.

23. A cassette according to claim 21 or 22, characterized in that the front wall (64) and the rear wall (62) are welded together.

24. A cassette according to any one of claims 1 to 23, characterized by a closed on one side cylindrical hygiene part (86), which is tightly connected to the protective cover (60).

25. Cassette according to one of claims 1 to 24, characterized in that the protective cover (60) carries a machine-readable identification (174).

26. A cassette according to any one of claims 1 to 25, characterized in that it comprises in the beam direction one behind the other holding devices for pieces of material (46, 48, 50), which preferably concentric held by them pieces of material (46, 48, 50) Give shape.

27. A cassette according to claim 1 or 2, characterized in that the supporting part (36) is at least in a region of the same part-cylindrical.

28. Memory sheet for use with a cassette

according to one of claims 20 to 27, characterized in that it has a receiving opening (52) for the

Hub part (34).

29. A storage film according to claim 28, characterized in that the receiving opening (52) as to a

Edge of the storage film (46, 48, 50) open slot is formed.

A storage sheet according to claim 28, characterized in that it is divided into two segments (46A, 46B) which abut one another at a line passing through the center of the receiving opening (52), this line being preferably perpendicular to a loading direction of the cassette (14) stands.

31. A storage film according to claim 30, characterized in that the two segments (46A, 46B) each have a half of the receiving opening (52) defining slot (52) and overlap at least partially.

32. A device for reading a storage film (46, 48, 50) in a cassette according to one of the claims

1 to 25 was exposed, characterized by a

Scanning unit (126 to 160), by a data processing device (162) and by at least one unit (170) for detecting the geometry of the cassette (14) or the storage film (46, 48, 50).

33. Apparatus according to claim 32, characterized in that the geometry recognition unit (170) has a

Camera includes.

34. Apparatus according to claim 32 or 33, characterized in that the geometry recognition unit a

Brand reader (172). 35. Device according to one of claims 32 to 34, characterized

in that the scanning unit (126 to 160) comprises a plurality of scan heads which have different readout surfaces (W1, W2, W3) which-preferably smoothly-adjoin one another and in that the scanning heads are controlled such that the memory film (46, 48 , 50) are read out along line segments, which together form a contiguous continuous scan line which preferably extends over the entire dimension of the storage film (46, 48, 50).

36. Apparatus according to claim 35, characterized

the scanning unit comprises three scanning heads, one of which is arranged above a center plane of the scanning unit and two symmetrically to this center plane.

37. Apparatus according to claim 35, or 36, characterized in that the scan heads circulating beams (128-1,

128-2, 128-3) and at different distances from the readout surface (Wl, W2, W3) are arranged and the angular velocity of the readout beams (128-1, 128- 2, 128-3) inversely proportional to the distance of its axis of rotation is selected from the read-out area.

38. Device according to one of claims 35 to 37, characterized

characterized in that the scanning units light sources (126-1, 126-2, 126-3) for readout beams (128-1, 128-2, 128-3) which, depending on the angular position of the respective readout beam (128-1, 128-2, 128-3) are controlled.

39. Apparatus according to claim 38, characterized

in that the switching times of the readout light sources (126-1, 126-2, 126-3) are controlled by electronic shutters (168-1, 168-2, 168-3) which depend on the angular position of a beam deflecting element (136-1, 136-2, 136-3).

40. Apparatus according to claim 35, characterized by at least one scan head (126 to 160), which between a first working position in which it has a first distance from a first read surface (Wl), and at least one second working position in which it has a second Distance from at least one further read-out surface (W2, W3), is adjustable, wherein the

Scan head (126 to 160) in the different working positions of different areas of the storage film

read out and the resulting sub-images are assembled electronically to an overall picture. 41. Apparatus according to claim 40, characterized

in that the scan head (126 to 160) is movable in three working positions, of which a first lies in a center plane of the device and two more are symmetrical to this center plane.

42. Device according to one of claims 32 to 41, characterized by a Aufbisseinrichtung (82, 84), which is provided with at least one mark, preferably with a plurality of spaced markers in the beam direction.

43. Device according to one of claims 32 to 42, characterized in that the cassette (14) is provided with holding means XX for an intraoral light detector YY.

44. Examination apparatus for generating X-ray images with a cassette according to one of claims 1 to

27, comprising a storage film and an X-ray source, characterized in that the X-ray source (12) comprises a small-diameter tubular housing portion (20) in which an anti-cathode part (28) is housed so that the X-rays are emitted predominantly in the backward direction and laterally Direction takes place, wherein preferably an aperture cap (192) is proceeding, which absorbs depending on their geometry parts of the votes in the rear half-space X-ray. 45. An examination apparatus according to claim 44, characterized in that the cassette (12) holds the piece of material (46, 48, 50) with a curvature corresponding to the curvature of a positioning surface of a scanning unit (204). 46. Apparatus according to claim 45, characterized in that the cassette is adjustable in the immediate vicinity of the scanning unit, so that the piece of material held in it can be moved flush onto the positioning surface of the scanning unit.

47. Apparatus according to claim 45 or 46, characterized by a transport device, by means of which the cassette (12) between a receiving position and the scanning unit adjacent position is movable.

48. Method for taking panographic slice images, characterized by the following method steps: a) arranging a panographic X-ray source

the structure to be examined; b) arranging a light detector, in particular one

Storage film, behind the structure to be examined; c) exposing the structure to be investigated; d) storing the image taken by the light detector; e) repeating steps a) to d) for at least

two modified relative positions between the X-ray source (12) and structure to be examined.

49. A method for recording panographic layer images, characterized by the following method steps: a) arranging a panographic X-ray source

the structure to be examined; b) arranging a light detector, in particular one

Storage film, behind the structure to be examined; c) exposure of the structure under investigation, during

at the same time d) the X-ray source and the light detectors are moved coordinated with each other so that a layer of the structure to be examined is sharply imaged for each light detector. A method for producing a panographisehen image characterized by the following method steps: a) arranging a panographisehen X-ray source before

the structure to be examined;

Selecting a light detector whose resolution substantially matches the resolution of the used X-ray source; c) exposure of the structure to be examined.

51. The method according to claim 50, characterized in that light detectors are used which carry machine readable marks and cooperate with a detector sensor whose output signal for controlling the

Exposure time is used. 52. The method according to any one of claims 48 to 51, characterized in that the image recorded by the light detector is converted under inverse transformation of the panographic imaging geometry into a panoramic image.