DE102006042731A1 - Lithotripter operating method, involves generating X-ray in operating position of percussion wave generator, and reproducing and representing X-ray produced by utilization surface on monitor by digital zoom - Google Patents

Abstract

The method involves generating an X-ray (B) containing a focus region (26) in an operating position of a percussion wave generator (20). Another X-ray is penetrated in a passage opening (38) provided in the generator and is limited in a receiving plane (42) of an X-ray receiver (34) on an utilization surface (44), which is smaller than its receiving surface (43). The X-ray produced by the utilization surface is reproduced and represented on a monitor by digital zoom. An independent claim is also included for a device for implementing a method of operating a lithotripter.

Description

The The invention relates to a method and a device for Operating a lithotripter, working in a working position a shock wave source an X-ray image containing the focus region is generated.

at Lithotripsy is a therapeutic method one in the body Concrement of a living being without surgery to destroy with the help of a focused ultrasonic shock wave from a shockwave source is produced. To damage is largely to avoid in the concretion surrounding tissue is On the one hand, it requires the focus of the lithotripter to be exactly the same Position the calculus. On the other hand, it is also necessary the progress in the destruction of the Visualize concrements to the number of required shockwave pulses to limit to the therapeutically necessary minimum.

For generating an X-ray image from the environment of the focus region of a lithotripter, it is for example from the DE 197 46 956 A1 It is known to couple an X-ray device with a lithotripter in such a way that the X-rays generated by the X-ray device pass through the focus region of the lithotripter. In this known device is a so-called "off-line" - or "Out-Line" -Anordnung, in which the center axis of the X-ray radiation with respect to the center axis of the generated by the shock wave generator focused material wave is inclined and the focus region approximately at the intersection This center axes is located.

alternative or in addition For this purpose, it is also known in the art, an X-ray image from the focus region by means of a so-called "in-line" arrangement, in which the X-rays through a in the shockwave source located central passage opening propagate in or against the propagation direction of the shockwave. In this arrangement falls the center axis of the X-rays at least approximately with the center axis of the focused shockwave together. adversely on such an "in-line" arrangement is now that the central Through hole only lets through a relatively small part of the X-ray radiation and the shock wave generator a relatively large one Part of the X-ray sensitive Reception area of the X-ray receiver covers. The unused part of the reception area is at one currently used in practice device (Siemens Lithoscope), depending on whether it is a so-called under-table or a top table treatment, 83 and 94% respectively.

This situation is in the 3 and 4 illustrated. The X-ray image generated by an X-ray receiver, in the illustrated example an X-ray image intensifier with a circular receiving surface, and correspondingly processed in an image processing device, is displayed in a monitor illustrated by a rectangular box 2 played. When using the entire receiving surface of the X-ray receiver would be a circular X-ray image 4 arise, the one intended for playback of the X-ray image part 6 the monitor surface almost completely fills. Due to the "in-line" arrangement, the X-ray beam is now limited to a central part and thus on the receiving surface of the X-ray receiver to an approximately circular effective area, which is significantly smaller than the total available receiving surface, so that on the monitor 2 generated x-ray image 4 from a likewise approximately circular central illuminated area 8th that consists of an unexposed area 10 (hatched drawn) is surrounded annularly. In 3 Now a situation is shown, as it results when using an X-ray image intensifier in a so-called under-table treatment. In 4 In the case of an upper table treatment, an "in-line" X-ray image is clearly illustrated, in which case the greater proximity of the passage opening to the X-ray receiver results in a significantly reduced central illuminated area 8th results.

Of the The invention is based on the object, a method for operating a lithotripter, in which in an "in-line" arrangement the user one possible meaningful visual support to control the progress of the destruction of the calculus. Furthermore the invention is based on the object, one by this method specify the institution to be employed.

With regard to the method, the object is achieved according to the invention with a method having the features of claim 1. In the method, an area containing the focus region X-ray image is generated with X-rays in a working position of a shock wave source, which pass through a shock wave generator located in the passage opening, the X-ray beam Location of an X-ray receiver limited to a usable area, which is smaller than the receiving surface, wherein the X-ray image generated by the Nutzfläche compared to a representation in which the X-ray image generated by the entire receiving surface is displayed on a monitor, enlarged displayed on the monitor. By this measure, the recognizability of the progress of the destruction of the calculus for the user is significantly improved, since the available for the image reproduction monitor area is better utilized and the user the Fort can track the shock wave treatment effortlessly.

In an advantageous embodiment of the invention, the enlarged illustration through a digital zoom, so that the central, the concretion containing body region of the patient (the "region of interest "(ROI)) can be seen with significantly better monitor utilization. Under digital Zoom is to be understood in the context of the invention, an image magnification, in the a pixel of an image data set in digitized form more than one pixel of the displayed image is assigned. at a pure digital zoom remains at a magnification spatial resolution unchanged, so that the enlarged picture inevitably in sharpness loses.

If as an X-ray receiver digital x-ray receiver (flat panel detector) with changeable spatial resolution is used, it is possible the digital zoom while increasing the spatial resolution.

A increase the spatial resolution is possible, too, when generating the X-ray image an analog X-ray receiver with an image intensifier is used. In this case, for the enlarged view of the picture alternatively or in addition to a digital zoom of the digitized image analogous to the spatial resolution of Image intensifier can be increased.

Either the digital zoom as well as the increase of the spatial resolution of the image intensifier can automatically take place when the X-ray device of a starting position in which a location of the concretion made will be driven into the "in-line" position, alternatively is in an advantageous embodiment provided that the user a the enlarged representation effecting Manually select operating mode can.

If Furthermore upon reaching the working position, the X-ray beam with a primary aperture on a bundle cross-section is limited, this at the location of the passage opening on the inside width limited, is an unnecessary Radiation exposure of the patient and the operating staff avoided.

Regarding the device, the object is achieved according to the invention with a Device with the features of claim 6, the advantages mutatis mutandis to the Process according to claim 1 specified advantages.

Further advantageous embodiments of the device are given in the appended subclaims, their benefits are also mutatis mutandis from the benefits of them each result in corresponding method claims.

to further explanation The invention is directed to the drawing. Show it:

1 and 2 in each case a device according to the invention in a schematic outline representation for a table top or a top table treatment,

3 and 4 the simplified X-ray image generated in an "in-line" arrangement from the focus region according to the prior art of an under-table or upper table treatment and reproduced on a monitor X-ray image in a simplified representation,

5 and 6 in each case a reproduced on the monitor in an "in-line" arrangement according to the invention X-ray image of the focus region in a Untertisch- or upper table arrangement.

According to 1 For example, a lithotripter includes a shock wave generator 20 , which has a water-filled coupling bellows 22 on the body surface of a patient 24 is attached. The shockwave generator 20 generates an ultrasonic shockwave that is in a focus region 26 is focused. With correct positioning of the shockwave generator 2 there is a calculus to be destroyed 28 in this focus region 8th ,

The lithotripter includes an X-ray device 30 with an X-ray source 32 and an X-ray receiver 34 , which in the example is an X-ray image intensifier. Shockwave source 20 and X-ray equipment 30 , in the example a C-arm X-ray device, are relative to the patient 24 and freely positionable relative to each other. In the figure, an "in-line" arrangement is now shown, in which the center axis 36 that from the X-ray source 32 emitted X-rays with the center axis of the shock wave generator 20 generated ultrasonic shock wave coincides.

The shockwave source 20 is located in a so-called under-table arrangement, where it from below to the body surface of the patient 24 is coupled. In this arrangement, the X-ray source is located 32 seen in the propagation direction of the X-rays behind the shock wave source 20 and the calculus 28 is located between the X-ray receiver 34 and the shockwave source 20 , In the shockwave source 20 there is a passage opening 38 put the x-ray on a narrow bundle 40 limited so that this at the site of the X-ray receiver 34 ie in the plane 42 his reception area 43 on a usable area 44 is limited, which is smaller than the receiving surface 43 ,

Between X-ray source 32 and shock wave generator 20 is an adjustable primary panel 46 already arranged, which from the X-ray source 32 Exiting X-ray beam limited to about the dimensions, through which he also through the passage opening 38 the shockwave source would be limited, thus avoiding unnecessary radiation exposure to the patient 24 or the operator. This adjustability of the primary panel 46 is in the figure by the double arrow 48 illustrated.

In 1 is yet another position of x-ray source 32 and X-ray receiver 34 which are in an off-line or out-line arrangement. Such an "out-line" arrangement is present, for example, if prior to the coupling of the shock wave source 20 the calculus 28 is located in order to position this correctly in the isocenter can. In this case, to exploit the entire receiving surface of the X-ray receiver 34 the primary panel 46 fully open.

After locating the calculus 28 becomes the shock wave generator 20 to the body surface of the patient 24 coupled and the X-ray device 30 moved to the "in-line" position, as indicated by the double arrow 49 is illustrated. Moving to the "in-line" position automatically becomes the primary shutter 46 moved back to an aperture, which at the passage opening 38 is adjusted. The from the X-ray receiver 34 generated signals are in a control and evaluation 50 evaluated and processed and the generated X-ray image B is on a monitor 52 shown. Input and controls, in the figure by a keyboard 54 illustrated, serve to select the appropriate application for the respective application by the user.

In the control and evaluation device 50 is now either automatically when reaching the "in-line" position (working position) or by prompting by the user via the input and control elements set an operating mode, which is an enlarged view of the area 44 generated X-ray image on the monitor 52 leads. This is done either exclusively within the control and evaluation 50 by processing the X-ray receiver 34 provided digital signals S by a so-called digital zoom. Alternatively or additionally, it is also possible, the spatial resolution of the X-ray receiver 34 if it is an X-ray image intensifier (electron optical image intensifier zoom) or a digital X-ray receiver (flat panel detector) with variable spatial resolution. While in a magnification performed exclusively with a digital zoom, the spatial resolution remains unchanged and, accordingly, a quality loss of the X-ray image is unavoidable, with an increase in the spatial resolution of the X-ray receiver 34 generates an enlarged X-ray image with simultaneously improved spatial resolution. In the case of a digital X-ray receiver, this is achieved by processing the pixel signals combined in normal resolution (for example 4 detector elements, 2 × 2 binning) separately from one another when enlarging the image (digital zoom). In other words: In the image reproduction, a pixel is no longer assigned an average formed of 4 pixel values but a single pixel value.

In 2 Now a situation is shown, as it results in an upper table arrangement. In this arrangement is the calculus 28 between the X-ray source 32 and the shockwave source 20 and thus at a greater distance from the through opening limiting the X-ray beam 38 , so that the cross-sectional area of the X-ray beam (effective area 44 ) on the receiving surface 43 of the X-ray receiver 34 opposite to the 1 is again significantly reduced.

In 5 and 6 Now situations are shown which result in an under table or top table arrangement, when an enlargement of the representation has been carried out according to the invention. It can be clearly seen that the central area 8th (The portion of the X-ray image generated by the effective area of the X-ray receiver) in both cases significantly larger on the monitor 2 is reproduced as in the in 3 and 4 X-ray images generated according to the prior art. In practice, an increase by a factor of 2 has proven to be expedient. The figures also clearly show the edges 56 In addition, in the illustrated example, the primary orifice can be slightly restricted to ensure that no X-rays escape into the environment, which can not be used diagnostically due to the steel limitation caused by the through-opening.

In 5 and 6 is also to recognize that part 58 For example, the available monitor area controls 60 for controlling the lithotripter or display elements 62 which informs the user of the current operating mode.

Claims (12)

A method of operating a lithotripter, wherein in a working position of a shockwave source ( 20 ) a focus region ( 26 X-ray image (B) is generated with X-rays, one in the shock wave source ( 20 ) passage opening ( 38 ), the X-ray beam in the receiving plane ( 42 ) of an X-ray receiver ( 34 ) on a usable area ( 44 ), which is smaller than its receiving surface ( 43 ), whereby that of the usable area ( 44 ) generated X-ray image (B) compared to a representation in which the of the entire receiving surface ( 43 ) generated on a monitor ( 2 ), enlarged on the monitor ( 2 ) is pictured. The method of claim 1, wherein the enlarged view done by a digital zoom. A method according to claim 1 or 2, wherein for generating the X-ray image, a digital X-ray receiver ( 34 ) is used with variable spatial resolution. The method of claim 1 or 2, wherein for generating of the x-ray image used an image intensifier will and for the enlarged view the spatial resolution of the image intensifier elevated becomes. Method according to one of the preceding claims, in to which the enlarged representation effecting Operating mode is freely selectable by the user. Method according to one of the preceding claims, in which upon reaching the working position, the X-ray beam with a primary diaphragm ( 46 ) is limited to a bundle cross-section, this at the location of the passage opening ( 38 ) limited to their clear width. Device for carrying out the method according to one of the preceding claims, comprising a lithotripter with a shock wave source ( 20 ) for generating a in a focus region ( 26 ) focused shock wave, and with an X-ray device ( 30 ) for generating an X-ray image from the environment of the focus region ( 26 ) by means of X-rays, one in the shockwave source ( 20 ) passage opening ( 38 ), the X-ray beam in the receiving plane ( 42 ) of an X-ray receiver ( 34 ) on a usable area ( 44 ), which is smaller than its receiving surface ( 43 ), as well as with a control and evaluation device ( 50 ) for the representation of the usable area ( 44 ) X-ray image B) on a monitor ( 2 ), compared with a representation in which that of the entire receiving surface ( 43 ) is reproduced, is enlarged. Device according to Claim 7, in which in the control and evaluation device ( 50 ) software for implementing the method according to claim 2 is implemented. Device according to claim 7 or 8, in which as X-ray receiver ( 34 ) A digital X-ray receiver is provided with variable spatial resolution. Device according to claim 7 or 8, in which as X-ray receiver ( 34 ) an image intensifier is provided and in its control and evaluation ( 50 ) software for implementing the method according to claim 3 is implemented. Device according to one of Claims 7 to 10, with operating and input elements ( 54 . 60 . 62 ) for selecting an enlarged mode operating mode by the user. Device according to one of Claims 7 to 11, having a primary diaphragm ( 46 ) for the X-ray beam, which automatically limits the X-ray beam to a bundle cross-section when it reaches the working position, at the location of the passage opening ( 38 ) limited to their clear width.