DE10262066A1 - Method of visualizing three dimensional data sets on a monitor, especially for a medical imaging device whereby part of the image is manipulated to bring it into the required geometric relationship - Google Patents

Abstract

The method is for visualizing three dimensional data on a monitor by means of an input device. The input device has means for selecting a reference point, means for setting a direction and means for adjusting a distance parameter. The method involves depicting the data set on the monitor and then selecting a point in the viewing area of the monitor. By means of the input device a reference point is selected which is projected onto a virtual surface whose geometric arrangement in relation to the image area of the monitor is known. The input device is used to set a direction which goes from the reference point to the selected point. The input device is further used to set a distance which is the distance between the reference point and the selected point. A depiction method of an area of the representation is manipulated, whereby this area has an adjustable geometric relationship to the selected point. Independent claims also cover a method of operation a medical examination device and a method of graphically positioning a layer to be measured.

Description

The The invention relates to a method for the visualization of data points a three-dimensional dataset. The invention relates also to a method of operating an imaging medical examination apparatus and a method of graphically positioning one by means of an imaging medical examination device measuring layer in a three-dimensional data set of a preparation measurement.

The Recording, presentation and processing of three-dimensional data sets wins with increasing computing capacity modern computer considerably in importance, since now also spatial Data with high data density, i. high resolution, recorded, displayed and can be edited. Just in modern imaging medical examination devices the progress in the development of such devices hand in hand with the possibility an adequate one Presentation and evaluation of medical data. This is for example in the medical large equipment in computed tomography or magnetic resonance imaging of the case or in the field of ultrasound sonography. For example, it is only the extraction of high-resolution angiography data a targeted medical intervention possible.

So far the representation of such three-dimensional datasets took place different way. For one thing, two-dimensional Sectional images displayed on conventional monitors. The third Dimension was due to the possibility of Indicate (flipping through) different layers indirectly shown. On the other hand, there is the possibility of perspective Representation, where these are calculated from the three-dimensional data sets got to. A virtual 3D object presented in such a way can then be changed by computer-controlled rotation, that is, by changing the perspective starting point, from different directions to be viewed as. This kind of 3D presentation can be transferred to projection systems.

A other type of presentation is based on a so-called 3D glasses, which creates a three-dimensional image in the viewer. A Further development leads for the three-dimensional representation in so-called cyberspace. there become three-dimensional data in a data helmet with data glasses recorded. The viewer is given a spatial impression, by the inclusion of the position of the viewer (given through the position of the data helmet) in the representation of the three-dimensional Record realistic becomes.

A Special position take volumetric monitors. An example is The 3D monitor of the company Actuality Systems, which is a real three-dimensional Generated image of an object to be imaged. This becomes a two-dimensional calculated image projected onto a rotating disk, so that for an observer creates a three-dimensional image. The application potential such 3D monitors is for example in the field of representation from data obtained by medical imaging equipment or in the Area of representation of complex three-dimensional structures, e.g. Molekühlen. Volumetric monitors have two advantages, among others. To the one are the pictures of a large surrounding area of the monitor visible, so that several observers simultaneously represented the Can see object. This is especially for Training purposes advantageous. On the other hand, a 3D monitor allows the Observers to focus on any points of the object and to get a sharp picture.

For the user It is now crucial how user-friendly a virtual perspective or real three-dimensional information displayed is accessible. Of importance are firstly an input device, with which you have a data point in a record secondly, the possibility to manipulate the data point, and thirdly a possible advantageous representation of the manipulated 3D data set.

Of the Invention is the object of a method for visualization of three-dimensional datasets, a method for operating an imaging medical examination device and a Method for the graphic positioning of an image by means of an image medical examination device Layer to be measured in a three - dimensional dataset Provide preparation measurement that indicates the orientation within a three-dimensional data set as well as its processing and visualization improve.

The first object is achieved according solved by a method for visualization of data points of a three-dimensional data set. In this procedure, the record is first displayed on a monitor. Then a point is selected in the display area of the monitor. For this purpose, three orientation parameters are entered with the input device described above. On the one hand, a reference point on a virtual surface, the geometric arrangement of which is known with respect to the display area of the monitor, is selected. On the other hand, a direction is set, which, starting from the reference point on the point to be selected in Dar range of the monitor. Furthermore, a distance variable is set which determines the distance of the point to be selected from the reference point. Subsequently, an area of the representation, which is in geometrically adjustable relation to the selected point, manipulated in its representation.

The used input device for orientation in a visualization of three-dimensional datasets has means of choosing a reference point, means of definition a direction and means for adjusting a distance size. A allows such input device it provides an observer of the visualization orientation parameter (e.g. Reference point, direction or distance size), the input preferably done by hand becomes. A hindrance to viewing or freedom of movement The observer should not make the visualization if possible. A such input device has the advantage that they are the one possibility offers, according to one natural Procedure Setting orientation parameters: How far is it? a point or region of interest from which point in which Direction away. On the other hand offers such an input device a flexibility in the order in which the orientation parameters are set become. For example, first the reference point, then the direction and finally the distance can be set or it can all orientation parameters be set almost simultaneously.

From Meaning with this procedure is the transmission of by means of the Input device adjustable orientation parameters on the Display area in which the visualization is displayed. For example, with the input device, a dot on one area selected, the area is in direct contact with the input device. The area is e.g. a pad on which the input device is moved. In the transmission of the point on the virtual surface this should be related to the viewport of the monitor and in relation to the viewer. The former is a prerequisite from the virtual area to be able to select from the point in the viewport. The latter is through the three-dimensional representation and their consideration, such as the viewing angle. For example, it is at one perspective view advantageous, the area between object and viewer and in the case of a volumetric monitor it is advantageous if the area encloses the monitor. The following is a differentiation between the point that with the input device is set, and the reference point the virtual area Due to the clear transfer of the one on the other only if they are important for understanding is. An advantage of this method is also its orientation at the natural Dealing with real three-dimensional objects.

The Method of visualizing data points may be on a display device to display a visualization of three-dimensional datasets. Such a display device also includes one previously described input device for orientation in a visualization, a visualization unit, which by means of the input device entered orientation parameters a representation of the visualization generated, and a monitor that represents the visualization. The advantage of this display device is that it an orientation within a visualization and its processing in an intuitive way.

Further The second object is achieved by a method for operating a imaging medical examination device using a previously described method for visualization of data points solved. This Method for operating an examination device has the advantage that for an information due to the improved representation easier obtained from medical examinations and used for diagnosis can be. On the other hand, this information can be used to to optimize further measurements with the imaging medical examination device by e.g. the area to be examined is more narrowly defined.

Further the third object is achieved by a method for graphic positioning of a medical imaging examination apparatus Layer to be measured in a three-dimensional dataset. This Record is obtained by a preparatory measurement with low resolution and displayed on a monitor. Using the above described Method of visualizing data points becomes a data point selected and the layer to be measured determined by a geometric Relation re of the data point. Preferably, the runs Layer through the data point. The advantage lies in the fact that using the input device, the orientation in the preparation measurement and so that the selection of a layer to be examined facilitates becomes.

In an advantageous embodiment of the input device for orientation in a visualization, the means for selecting the reference point are designed such that they allow a positioning of the reference point on a two-dimensional surface and that the position on this Flä recognize. This has the advantage that the positioning of the reference point takes place in a two-dimensional surface and not in three-dimensional space, but presupposes that the two-dimensional surface is later set in spatial relation to the visualization.

In a special embodiment the input device are the means for selecting the reference point a conventional mouse, whose movement, for example, on a surface registered in two dimensions. The mouse is preferably with connected to a computing unit to which it transmits recorded data. This embodiment has the advantage that they use known technologies can.

In a special embodiment of the input device include the Means for determining the direction of tilting in one direction Lever as well as a sensor that tilts the lever in the direction registered. Such a lever may be a tiltable joystick, wherein the tilting, for example, by the detection of the tilted Winkels or monitored by the duration of the tilting process and at an angle is converted. Starting from the position of the reference point the two-dimensional surface if two angles are sufficient in two different directions, to define a direction clearly in space.

In a particular embodiment the input device, the joystick is structurally connected to the mouse, to make a multi-function mouse. This has the advantage that two common to a user Input devices are combined.

In a further advantageous embodiment of the input device comprises the input device a pointer, preferably freely movable is, for example, he has no connection cable to possibly required Units up. This pointer is both a means of choosing the Reference point as well as a means of determining the direction. to Use of the pointer as an input device is needed Means both the location of the pointer in the room and his Determine alignment in the room. Subsequently, the location and the Orientation relative to the visualization can be set to the reference point and to determine the direction.

In a particularly advantageous embodiment of the input device the determination of the position and orientation of the pointer is done by means of Ultrasonic transit time measurements. The advantage of ultrasonic transit time measurements lies in the fact that the resolution, in this case the spatial resolution, is finely enough adjustable to determine location and direction clearly.

In In a development, the pointer comprises at least two ultrasonic transmitters, which are preferably arranged at the ends of the pointer. From the ultrasonic transmitters emitted signals are received by receiving units the input device registered. Are the positions of the receiving units known in terms of visualization, and are the ultrasound transmitters and the receiving units with means for synchronization in time synchronized (for example, over a radio link), so can from the transit times between the ultrasonic transmitter and the receiver units Location and orientation of the pointer can be calculated. The advantage This training is that it is a simple and well-known Form of ultrasonic transit time measurement used.

In In another development, the pointer comprises at least two Ultrasonic reflectors, in turn, preferably at the ends of Zeigestabs are arranged. Ultrasonic transmitters whose positions are known, send signals that are different from the reflectors be reflected strongly and with a characteristic pulse shape. The such encoded reflected ultrasonic signals are received units, whose position in relation to visualization is also known, recorded and by comparing the signals with the known Reflection patterns associated with the respective ultrasonic reflector. The advantage of this development lies in the passive mode of operation of the pointer, which acts only as an ultrasonic reflector, so that less expensive electronics are housed in the pointer got to.

In a further advantageous embodiment of the input device For example, the means for adjusting the gap size comprise a rotatable one cogs and a sensor for detecting the rotation. The advantage of such wheel is that he is both in the pointer as well as in the multi-function mouse can be accommodated easily. The by a rotation of the wheel generated signals are, for example, via radio to a processing Unit transmitted.

In a further advantageous embodiment, the input device additionally a key to trigger of a signal. One or more of such buttons may be control signals generate, which are transmitted to a computing unit. The advantage Such keys is that they are beneficial to use and easy to integrate into the pointer or the multi-function mouse are.

In a further advantageous embodiment, the input device additionally comprises means for outputting the reference point, the direction and the distance size. These means for output can be accommodated, for example, in a central processing unit which, for example, also includes and controls the synchronization unit and / or the receiving units. The means for output can be connectable to the 3D presentation systems described above.

In an advantageous embodiment of the method for visualization of data points become this on a 3D monitor shown. For example, such a monitor has a hemispherical display area on, is the virtual area, to which the reference point is projected, preferably also hemispherical placed around the viewport.

In another embodiment The visualization process will display the object on a 2D monitor shown in perspective. Preferably, the monitor screen area is called virtual area chosen on which is selected with the means for selecting the reference point of the reference point.

In this and in the previous embodiment of the method the geometric arrangement of the virtual surface in relation to the display area known. In a further development, two angles are used to indicate the direction entered with the input device. These angles will be in place of the reference point and determine the direction in the display area, in the one to be selected Point lies. The legs of the angle are preferably in the Tangential plane vertical, non-parallel planes, where the Tangent plane the virtual hemisphere or monitor screen surface in place of the reference point. Alternatively, the legs of the angle lie in the tangential plane.

In a particularly advantageous embodiment of the method for Visualization becomes the virtual surface with a first coordinate system, for example in length and latitudes divided. Finds the choice of the reference point in a second coordinate system, so the transmission the reference point determined by the means for selecting the reference point on the virtual surface through a transmission from the first to the second coordinate system.

In an advantageous embodiment of the visualization method becomes during the adjustment of the orientation parameters continuously an arrow on each momentarily by the orientation parameters certain data point, with the top of the arrow at the data point and the fuselage of the arrow towards the reference point shows.

In a further development, the arrow is drawn as long as the Orientation parameters are varied. Only by pressing a Button of the input device, the orientation parameters are set and the manipulation of the representation is done.

In a particularly advantageous embodiment of the method for Visualization becomes by selecting the reference point at the same time also selected an area its volume and / or shape either preset or changeable is. This has the advantage of not just one point, but one can be manipulated by the point certain area, the can be adjusted as needed.

In In an advantageous embodiment, an area is manipulated, which lies between reference point and selected point, wherein the area to be manipulated tapers conically to the selected point. Of the Range moves continuously with a change in the selected point With. This has the advantage that the gaze of an observer along of the cone on the selected Point is manipulable, e.g. a hindrance to the view of the chosen Area to avoid.

In a particular embodiment of the method of visualization, the illustrated three-dimensional records and / or the selected one Area in various ways, e.g. skeletal, opaque, transparent or semi-transparent. An opaque representation For example, it only shows the surface of a 3D object. At a skeletal appearance, only certain data points become opaque represented, e.g. in angiography, in the blood vessels, respectively the surfaces the blood vessels in her Networking be represented grid-like. In a transparent or partially transparent representation of a data point is this not visible, or he covers up underlying data points are not complete.

In the partially transparent representation, the data points are assigned degrees of transparency which influence the representation of the respective data point. For example, the bleed through of the background data points, ie the data points located in the observation direction behind a data point, is controlled. This can be done with special volumetric 3D monitors by the intensity of the representation of the respective data point. In this way, transmission effects can be generated. The assignment of a degree of transparency takes place, for example, from a frequency distribution of the data points via the signal intensity. A manipulation of the data points as a function of the signal intensity allows, for example, the data points outside of an intensity interval appear transparent. In this way, an unnecessary intensity range in a visualization can be suppressed.

In another advantageous embodiment of the visualization method, the area to be selected has a geometric one Shape, e.g. that of a sphere or that of a cuboid. About a cone, its content can be displayed transparently in this case a viewer first e.g. position the cuboid and then look into the cuboid, the content of the cuboid being e.g. is shown skeletal. Alternatively, the contents of the cuboid and those bordering on the cone side surface shown transparently. The remaining side surfaces of the Cuboids form correspondingly positioned sectional images through the 3D object. This has the advantage that, e.g. simulate endoscopic procedures can.

In An advantageous development of the method is a cut surface the selected one Point, with the data points on one side of the cut surface transparent and which are opaque on the other side. This corresponds to the usual 3D illustration of a sectional image.

In another embodiment The method of visualization is next to a three-dimensional Representation of a two-dimensional representation on a 2D monitor generated. In addition to the two-dimensional representation of a sectional image becomes the location of the sectional image in the three-dimensional representation e.g. indicated in the form of a frame. This allows a clear orientation and positioning the sectional image in the 3D representation as well a high resolution Presentation of the section on the 2D monitor.

In a further advantageous embodiment of the method for Visualization becomes the selected one Range determined by selecting the points whose value is one characteristic size in one Window area by the value of the selected point. The characteristic Size is for example the signal intensity of the chosen Point. This embodiment has the advantage of having a skeletal representation of points with a similar one Value of the characteristic size receives.

In a particularly advantageous embodiment of the display device to display a visualization of three-dimensional data sets the visualization unit means that the reference point, the Direction and distance in relation to a virtual surface sets. The funds can include a computing unit that with a computer program the geometric relations between the orientation parameters, the virtual area and the representable volume.

In a further embodiment of the method of graphic positioning, after the Layer based on the preliminary Measurement selected and positioned high with an imaging medical examination device resolution Measurement performed and displayed on the monitor.

Further advantageous embodiments The invention are characterized by the features of the respective subclaims.

The following is the explanation of several embodiments based on 1 to 13 , Show it:

1 a display device for displaying a visualization of three-dimensional data sets,

2 a multifunction mouse with multiple functionalities,

3 a sketch that illustrates the use of a pointer,

4 an example of the choice of a virtual surface when using a 3D perspective view with a 2D monitor,

5 a sketch for clarification of orientation parameters that can be input by means of input devices,

6 a first measurement setup that allows the determination of the position and orientation of a pointer,

7 a second measuring setup that allows the determination of the position and orientation of a pointer,

8th a sketch to clarify the in 7 used coded reflection,

9 schematic sectional views of manipulable volumes,

10 a 3D angiography image of a magnetic resonance tomography device,

11 a 3D image of a knee joint of a computed tomography device,

12 an intensity frequency distribution of data points and their degree of transparency distribution set by means of fenestration,

13 a sketch to illustrate the selection of a layer in the presentation space,

14 a figure to illustrate the positioning of layers in magnetic resonance imaging.

1 shows a display device 1 to display a visualization of three-dimensional data sets. The records are using a magnetic resonance imaging device 3 , representative of medical imaging equipment. The three-dimensionally recorded head in this case 5 a patient is using a 3D monitor 7 shown. The 3D monitor 7 is in this case a real 3D-monitor, which is an object, here the head 5 , within its spatial presentation volume 8th as a spatial illustration, here a head picture 9 , represents. Alternatively, the 3D monitor could 7 also a conventional monitor, ie a monitor with a two-dimensional presentation space, which images the head from a spatial perspective.

With the help of input devices 11 . 13 , for example, a multi-function mouse 11 or a pointer 13 , is an orientation within the presentation volume 8th and thus within the three-dimensional visualization, ie in the head image 9 , possible. Parameters required for this purpose are digitized, for example, and output to the visualization-calculating and generating unit via cable or infrared interface.

For example, using the input devices 11 . 13 one point 14 in the head picture 9 selected, for example, a point 14 surrounding virtual section along a transparent cone 15 to be viewed as. In addition, the cut surface on a conventional 2D monitor 17 be imaged. In 1 eg a cross-sectional picture 19 through an equilibrium organ of the head 5 displayed.

The observer can see the cone 15 with the help of input devices 11 . 13 to any position in the imaging volume of the 3D monitor 7 align, ie every point 14 in the presentation volume 8th can be viewed from any direction.

The 3D monitor 7 the display device 1 additionally has a computing unit 21 on, the each entered with the input device reference point 23 , which sets the direction and the distance with respect to a virtual surface, their geometric arrangement to the representation volume 8th is known. The arithmetic unit 21 thus has means for determining the geometric relations between the 3D data and the input parameters of the input devices 11 . 13 computationally efficient combined and calculated. In other words, the arithmetic unit orders 21 the entered reference point 23 a point on the virtual surface, starting from the input direction along the input direction of the point 14 or the area surrounding it is selected in the three-dimensional data set. The calculations are carried out as quickly as possible, for example, by optimizing processors on graphical relations.

2 shows a multi-function mouse 11 with several different functional means. Basis of the multi-function mouse 11 is a substructure 31 whose operation corresponds to a conventional PC mouse. By means of a ball 33 the movement is measured on a pad in two directions, the in 2 are designated with X or Y direction. A movement of the multi-function mouse 11 on the document leads to a change in the X and Y coordinates, which are registered and by means of the arithmetic unit 21 is transferred to a movement in a coordinate system of a virtual surface. Alternatively, the movement of the multifunction mouse 11 optically detectable on the surface (optical mouse).

In the example of the 3D monitor off 1 For example, the virtual area becomes the hemispherical surface of the presentation volume 8th represented, which can be divided, for example, in longitude and latitude. For example, corresponds to a movement of the substructure 31 along the X-direction a movement at the latitude and a movement along the Y-direction of a movement on the longitude.

An alternative to the substructure 31 like a mouse is a trackball or trackpad system. In this case, changing the coordinates is registered directly by rotating the ball or by touching the trackpad.

On the substructure 31 is a joystick 35 attached, which allows to register a deflection in two, for example, orthogonal directions. The deflection in one direction may, for example, determine an angle by the degree of deflection or by the duration of the deflection. With the help of the arithmetic unit 21 For example, an angle entered in this way is converted into an angle defining a direction pointing out of the virtual area from the reference point. Tilting the joystick 35 forwards or backwards, for example, corresponds again 1 corresponds to an angle change in the plane of the longitude of the reference point and a lateral tilting an angle change in a plane perpendicular to the plane of longitude and perpendicular to the tangent plane to the hemispherical surface of the presentation volume 8th at the reference point, with all planes going through the reference point.

In addition, has the multi-function mouse 11 three buttons 37 . 38 . 39 , which are similar in their operation and operation of the left, right and middle mouse button of a conventional mouse. With these buttons additional inputs can be made, eg to fix the angle or the reference point or to set it to an initial value. The middle mouse button 39 is additionally designed as a wheel, whose rotation is registered and the arithmetic unit 21 in a distance size, for example, the length of an arrow from the reference point 23 , is converted.

3 illustrates the use of the pointer 13 when choosing a point 14a in the presentation volume 8th , Due to the free mobility of the pointer 13 a user has the option, from any desired position, of any area within the presentation volume 8th to show. In 3 the user points with the pointer 13 on the 3D object 41 , While using the pointer 13 its position and orientation are in relation to the volume of presentation 8th measured. The arithmetic unit 21 the display device 1 calculates with these sizes a straight line 42 along the imaginary extension of the pointer 13 runs.

To an arrow 43 in the presentation volume 8th to be able to draw, calculates the arithmetic unit 21 the puncture point 23a the straight line 42 with the surface 45 the presentation volume 8th , The puncture point 23a corresponds to the reference point 23 which is entered with the pointer. The virtual surface on which the reference point 23 is positioned in this case by the surface 45 the presentation volume 8th educated. Will using a wheel 47 in the pointer 13 additionally entered a distance size, this determines the distance of the point to be selected 14a from the puncture point 23 along the straight 42 , Alternatively, the distance by a translational movement of the pointer 13 along the straight 42 be adjusted by the translational movement while pressing a button 49 is registered.

Is this way the point 14a in the 3D object, the arrow becomes 43 along the straight 42 drawn, with the arrowhead on the point to be selected 14a shows. The arrow 43 moves continuously with a change in the point 14a with which by a movement of the pointer 13 is caused. By selecting the point 14a can also be the representation of an area around the point 14a in the 3D object 41 to be changed. Preferably, the area to be changed is preset as required or, for example, by means of the input device 11 . 13 be determined.

Using buttons 49 pointing at the pointer 13 can affect the process of the selection process and the presentation of the 3D object 41 in the presentation volume 8th be taken. For example, they can be used to switch between different modes of presentation.

To disrupt display and selection process due to jitter in handling the pointer 13 to suppress, the calculation of the reference point 23 slows down, causing position changes of the reference point 23 on the surface 45 only delayed and / or steamed done. Furthermore, for example, using one of the buttons 49 the reference point 23 be fixed in its position, so that from then on only the alignment of the pointer 13 must be controlled and measured to the direction of the line and thus of the arrow 43 to calculate.

To speed up the calculations, the arithmetic unit could 21 eg the surface 45 the presentation volume 8th into a coordinate system with latitude and longitude 51 . 53 subdivide.

4 shows an example of the choice of the virtual area 55 when using a 3D perspective view on a flat screen 57 , The virtual area 55 is located on the screen surface, so that it is always between the viewer and presentation. The with the multi-function mouse 11 scanned area, eg a mouse pad 58 , can be scaled to the virtual surface 55 be transmitted. Scaling is particularly easy if for both surfaces, ie for the mouse pad 58 and for the virtual area 55 , Cartesian coordinates 59 . 59a for determining the position of the multifunction mouse 11 and the reference point 23b be used.

5 clarifies the orientation parameters generated by the input devices 11 . 13 can be entered. 5 shows two examples in which the angle inputs for determining the direction do not take place in the planes of latitude and longitude, but in which the angle inputs refer to the deviation from the normal of the tangent plane through the reference point. In the examples, using the input devices 11 . 13 the reference points 61 . 61a entered. They are at different positions on the surface 45 of the presentation volume mens 8th , Furthermore, the distance variables 63 . 63a in 5 plotted the distance from the reference point 61 . 61a to determine the points to be selected, which at the tips of the arrows 64 . 64a lie. Additionally are in 5 tangent 65 . 65a to the surface 45 through the respective reference points 61 . 61a shown. In the first example of the 5 is the arrow 64 in a plane that is perpendicular to the tangent plane 65 stands. In this case, no angle deviation was entered for at least one direction. In the second example, using the joystick 35 or the orientation of the pointer 13 an angle 67 entered the deviation of the direction of the arrow 64a from a normal 68a to the tangential plane 65a determined in one direction.

6 shows the measurement setup, which determines the position and orientation of the pointer 13 allowed. In the pointer 13 There are two ultrasonic transmitters S1, S2. The two transmitters alternately transmit an ultrasonic pulse which is received by at least three receivers E1, E2, E3, En after certain transit times U1, U2, U3, Un. From the transit times U1, U2, U3, Un, the distances between the ultrasonic transmitters S1, S2 and the receivers E1, E2, E3, En can be calculated using the speed of sound. The locations of the transmitters S1 and S2 can be determined from the distances and the known positions of the receivers E1, E2, E3, En. This is the position of the pointer 13 and its orientation is clearly defined in space and can be easily related to the volume of presentation 8th be set.

With the help of the arithmetic unit 21 can calculate the imaginary extension of the pointer and in the presentation volume 8th be drawn.

To determine the transit times U1, U2, U3, Un, the transmitters S1, S2 must be synchronized with the receivers E1, E2, E3, En. This is done with a synchronization unit S and the associated synchronization paths TE1, TE2, TE3, TEn, TS, TS1, TS2, the synchronization unit S, such as a radio transmitter, with the receivers E1, E2, E3, En and the transmitter S1, S2 in pointer 13 connect. In addition, it is determined by means of the synchronization unit S in which order the ultrasound transmitters S1, S2 transmit.

With the wheel 39a As described above, the distance from the reference point and the point or volume to be selected is set.

Thus a trouble-free operation with the pointer 13 around the 3D display, more than three ultrasonic receivers E1, E2, E3, En are used to prevent shielding effects by the 3D monitor.

7 illustrates a second method of measurement, with the help of ultrasonic reflectors R1, R2 in the pointer 13 the location and orientation of the pointer 13 in relation to the presentation volume 8th can be determined. By means of an ultrasonic transmitter S3 an ultrasonic pulse train is emitted. The ultrasonic pulse train consists of a sequence of short pulses with fixed amplitudes and frequencies. The pulses are reflected at the reflectors R1 and R2 and subsequently registered by the receivers E1, E2, E3, En. The transmitter S3 and the receivers E1, E2, E3, En are again synchronized via a synchronization unit S. The two reflectors R1, R2 are like the transmitters S1, S2 in 6 at the ends of the pointer 13 arranged at a distance L.

The reflectors have the property that they are different resonant to the different frequencies in the ultrasonic pulse train, that reflect the ultrasonic pulses different levels. In this way, the ultrasound pulses are encoded by the reflectors R1 and R2 so that they can be distinguished from the receivers E1, E2, E3, En on the one hand and distinguished from reflections on foreign bodies on the other hand. From the transit times, the distances between the reflectors and the receivers can be calculated again, so that the position and orientation of the pointer 13 in relation to the presentation volume 8th with the help of the arithmetic unit 21 are calculable.

8th illustrates the mode of action of the coded reflection on the example of the reflections on the reflector R1 and on a foreign object. During the coding, the individual pulses of a signal transmission pulse train SP whose course of the amplitudes A1, A2,... An at the frequencies f1, f2,... Fn over the time t in 8th is shown schematically, each reflected with a defined reflection factor at the reflector R1. This generates a reflected echo signal pulse train EP1 with the amplitudes B1, B2,... Bn. In this case, the pulse widths and pulse shapes of the receive pulse train EP1 can also be modified characteristically by the reflection of the transmit pulse SP at R1. The reflection on a foreign object is not controllable and also generates an echo signal pulse train EPF, wherein the reflection of the foreign object of the amplitude characteristic as an example in 8th was hardly changed. The amplitude profiles of the echo signal pulse train EP1 and of the echo signal pulse train EPF over the time t are also shown in FIG 8th shown.

Depending on the reflector, reflected echo signal pulse trains have different amplitude profiles and pulse shapes that are idealized by reflector-specific echo signals, for example by the in 8th illustrated echo signal EE1 determines who the. By means of a correlation K of received signal and reflector-specific expected echo signals EE1, an assignment of the signal to the reflectors R1, R2 or to foreign objects can be carried out. Contains the received signal, for example, the echo signal pulse train EP1, one obtains a correlation value K1 in the correlation K with the echo signal EE1. This is greater than the correlation value KF which would be obtained with the correlation K of the echo signal pulse train EPF reflected by the foreign object with the echo signal EE1. If the echo signal pulse train EP1 and the echo signal pulse train EPF are received successively, the result in 8th illustrated time course of the correlation of received signal and echo signal EE1.

For the calculation the spatial Positions of the reflectors R1, R2 will be the durations of the corresponding ones pulse trains from the time of sending to receipt by E1, E2, ... En measured. From the maturities can be ellipsoids with the focal points S3, E1, E2, E3, En calculate. The point of intersection from at least three ellipsoids marks the positions of the reflectors R1, R2. To improve the accuracy of the orientation can the known distance L of the reflectors R1, R2 in the calculation be included. additionally can the resonance frequencies of the reflectors R1, R2 differ.

A presentation device 1 For the representation of a visualization of three-dimensional data sets allows eg in the medical and especially in the radiological representation of three-dimensional data a variety of modes of representation and corresponding applications. Especially in the case of real 3D monitors, such a presentation device can be carried out for the simulation and training of operations with the aid of virtual surgical instruments. Subsequently, the data of the simulated operation can also be forwarded to an operation robot.

In a first representation, it should be possible with the help of the input devices 11 . 13 to sting in an opaque 3D object, rendering the 3D object transparent in the vicinity of the arrow. This is to make the volume to be examined at the pointer tip visible from the outside. The shape and size of the transparent volume can be adjusted, for example, to a conical shape. Alternatively, the arrow itself can be displayed transparently, so that it does not obscure areas of the displayed object.

In a variation of this representation, an arbitrarily shaped transparent volume (eg sphere or cube) is placed in the 3D object using the arrow. The position and orientation of the volume relative to the arrow is also adjustable. For example, the volume may be through a virtual frame or cage in the viewport 8th indicated and with the input device 11 . 13 be moved through the 3D object and positioned. For example, the 3D object on one side of the frame can be displayed transparently.

Another way to define such a volume is to use the input device 11 and 13 several points are marked, which together span the volume or a portion of the volume, eg an area.

In a representation, the data points within the volume for example, transparent.

On This way, for example, is an active editing of the data possible, such as. a cut out of disturbing Bones in the imaging.

Advantageous embodiments of the example transparent switchable volume are in 9 shown in section. Around the volume in the area of the arrowhead 71 along the straight 42a to be able to look at the volume in the form of a cone 73 be educated. The end of the cone 73 in the area of the arrowhead, ie the selected point 14b is, for example, either as a level 74 or as a hemisphere 75 shaped.

A further representation is that of the grid representation 76 , For clarity shows 10 a 3D angiography image with a magnetic resonance tomography device and 11 a 3D image of a knee joint with a computed tomography device. The for a grid representation 76 required data sets can be generated eg by windowing.

In a simple version of the fenestration, only data points of similar intensity I are displayed. For this purpose, the number N of data points with an intensity I is entered in a frequency distribution H, see 12 , In addition to the intensity 2 It is also possible to select a frequency distribution H of another characteristic variable, such as, for example, flow or diffusion. In the frequency distribution H becomes a center value 77 and a window width 79 around the middle value 77 selected. The data points that lie outside the window defined in this way are displayed transparently, for example. The data points within the value range are specially processed in their presentation, eg their degree of transparency T decreases linearly with increasing intensity (transparency degree representation 80 ). This causes in the representation that a point with a high intensity value I in the value range does not have any data points that are in Viewing direction is behind this point, let shine through.

By The variation of the window parameters can increase the transparency of the 3D object for all Intensity ranges be adjusted continuously.

The The fenestration approach allows it to be set to e.g. the intensity scale to select a range of a recording and modify it, e.g. transparent or opaque.

In A first clarification of this procedure becomes a 3D object at a representative Spot marked. Subsequently All data points with the same or at least a similar intensity become transparent connected. This allows the viewer, e.g. a radiologist, Data points that are not relevant to the examination are transparent to switch, e.g. suppression of pale adipose tissue in a magnetic resonance image.

In a second clarification of this procedure, the data points which have a continuous intensity profile starting from the representative point are imaged opaque. This gives a grid representation of the 3D angiography image in 10 comes close. On the other hand, if the areas selected in this way are switched to transparent, this results in cutting out areas that obstruct the view, for example bones.

Using the display device, it is also possible layers in the presentation room 8th to select. A clarification of the procedure shows 13 , In the presentation room 8th there is a 3D object 41a , In addition, there is an arrow 81 shown on a selected point 14c shows. The layer to be selected 83 is relative to the plane that is orthogonal to the arrow 81 stands, for example, inclined by 45 ° and by a frame 85 and one on the 3D object 41a drawn outline 87 clarified. The selected layer plane 83 can either be displayed alone with the 3D monitor or it can be displayed on the 2D monitor at the same time if the 3D monitor is used together with a 2D monitor.

In many cases, it is convenient to have the arrowhead at any point in space by means of the keys of the input device 11 . 13 to fix, and then, for example, the direction of the arrow or the angle of the selected layer to the arrow 81 to vary.

One possible application is the graphical layer positioning in magnetic resonance imaging, in which a fast 3D measurement is performed in preparation. The acquired 3D data set includes the body region to be examined at low resolution and is displayed with a 3D monitor. An example shows 14 , The user can enter the 3D object, here the head image 91 , the next to be measured layers 83 , characterized by the frame 85 Realistically align and position.

Claims (27)

Method for visualizing data points of a three-dimensional data record on a monitor ( 7 . 57 ) by means of an input device ( 11 . 13 ) with means for selecting a reference point ( 23 . 23b . 61 . 61a ), means for defining a direction and means for setting a distance size ( 63 . 63a ) with the following procedural features: - displaying the data set on the monitor ( 7 . 57 ). - selecting a point ( 14 . 14a . 14b ) in the display area of the monitor ( 7 . 57 ), whereby by means of the input device ( 11 . 13 ) a reference point ( 23 . 23b . 61 . 61a ), which is placed on a virtual surface ( 45 . 55 ) whose geometric arrangement in relation to the display area ( 8th ) of the monitor ( 7 . 57 ), wherein by means of the input device ( 11 . 13 ) a direction is set starting from the reference point ( 23 . 23b . 61 . 61a ) on the virtual surface ( 45 . 55 ) to the item to be selected ( 14 . 14a . 14b ) in the display area ( 8th ) of the monitor ( 7 . 57 ), and wherein by means of the input device ( 11 . 13 ) a distance size ( 63 . 63a ), which sets the distance of the point to be selected ( 14 . 14a . 14b ) in the display area ( 8th ) from the reference point ( 23 . 23b . 61 . 61a ). Manipulating a representation of a region of the representation of the data set, wherein the region is in adjustable geometrical relation to the selected point ( 14 . 14a . 14b ) stands. Method according to claim 1, characterized in that by pressing a button ( 37 . 38 . 39 . 47 . 49 ) of the input device ( 11 . 13 ) the reference point ( 23 . 23b . 61 . 61a ), the direction and the distance size ( 63 . 63a ) be determined. Method according to Claim 1 or 2, characterized in that the data record is stored on a 2D monitor ( 57 ) three-dimensional perspective or on a 3D monitor ( 7 ) in three room dimensions. Method according to one of claims 1 to 3, characterized in that the data record from an imaging medical examination device ( 3 ) is produced. Method according to one of claims 1 to 4, characterized in that the virtual surface ( 45 ) the display area ( 8th ) at least partially surrounds spherical. Method according to one of claims 1 to 5, characterized in that the virtual surface ( 45 . 55 ) is divided with a coordinate system. Method according to one of claims 1 to 6, characterized in that the coordinate system, the virtual surface ( 45 ) in latitudes and longitudes ( 51 . 53 ). Method according to one of claims 1 to 7, characterized in that the direction by means of two angles ( 67 ) whose base limb is perpendicularly in two on a tangential plane ( 65 . 65a ) standing planes, wherein the tangential plane ( 65 . 65a ) at the reference point ( 23 . 23b . 61 . 61a ) the virtual area ( 45 . 55 ). Method according to one of claims 1 to 8, characterized in that with a registered by a sensor rotation of a rotatable wheel ( 39 . 47 ) the distance size ( 63 . 63a ) is set. Method according to one of claims 1 to 9, characterized in that an arrow ( 43 . 64 . 64a ) in the display area ( 8th ) whose peak ( 71 ) at the selected point ( 14 . 14a . 14b ) lies. Method according to one of Claims 1 to 10, characterized in that the region to be manipulated comprises a volume around the selected point ( 14 . 14a . 14b ). Method according to one of Claims 1 to 11, characterized in that the region to be manipulated has a volume along the connecting line ( 42 . 42a ) between the reference point ( 23 . 23b . 61 . 61a ) and the selected point ( 14 . 14a . 14b ). Method according to one of claims 1 to 12, characterized in that the volume along the connecting line ( 42 . 42a ) between the reference point ( 23 . 23b . 61 . 61a ) and the selected point ( 14 . 14a . 14b ) tapers conically to the selected point. Method according to one of claims 1 to 13, characterized in that at least a part of the three-dimensional data as an opaque object ( 91 ) is pictured. Method according to one of claims 1 to 14, characterized that at least part of the three-dimensional data in a skeletal grid representation is pictured. Method according to one of claims 1 to 15, characterized that the selected area is displayed transparently. Method according to one of claims 1 to 16, characterized that in the manipulation of the area the corresponding data points transparency levels (T), which is determined by the location of each data point in a frequency distribution (H) the three-dimensional data are determined in the distribution the data points over a characteristic size (I) is plotted is. Method according to claim 17, characterized in that that the frequency distribution (H) an intensity frequency distribution in which the distribution of the data points is plotted against the signal intensity (I) is. Method according to one of claims 1 to 18, characterized in that the region to be selected comprises an area ( 19 . 83 ) and that the data points on one side of the surface ( 19 . 83 ) are displayed transparently. Method according to claim 19, characterized in that the surface ( 19 . 83 ) a sectional area through the display area ( 8th ) of the monitor ( 7 ). Method according to claim 19 or 20, characterized in that the data points of the surface ( 19 . 83 ) on a 2D monitor ( 17 . 57 ) are displayed in two dimensions. Method according to one of claims 1 to 21, characterized that each data point is assigned a characteristic value and that the selected one Range includes data points that have a similar characteristic Have value. Method for operating an imaging medical examination device ( 3 ) using a method according to any one of claims 1 to 22. Method for the graphic positioning of a medical imaging device ( 3 ) layer to be measured ( 83 ) in a three-dimensional data set of a preparatory measurement with the following procedural features: - performing the preparatory measurement with low resolution and displaying the data record. By means of a method according to one of claims 1 to 22, selecting a point ( 14c ) and the layer to be measured ( 83 ) represented by a geometric relation with respect to the selected point ( 14c ) is defined. A method according to claim 24, characterized in that the layer to be measured ( 83 ) in the representation of the visualization ( 9 . 41 . 41a . 91 ) as an outline ( 87 ) is drawn. Method according to claim 24 or 25, characterized that the corresponding cross-sectional image is displayed two-dimensionally on a 2D monitor 17. Method according to one of claims 24 to 26, characterized in that the layer to be measured ( 83 ) with an imaging medical examination device ( 3 ) is measured and displayed.