Technical field The present invention relates to a device for taking radiographs by means of digital image plates.

The object of the present invention is to obtain a device for taking a radiograph by means of digital image plates.

Background of the invention Using conventional X-ray film it has been possible to take radiographs of whole legs or a whole spine and thereby it has been possible to carry out measurements on the picture obtained in order to ascertain a result of a treatment, or to obtain a diagnosis prior to a treatment.

Today's digital technique using digital image plates, radiographs having the size 35 x 43 centimetres, as the largest, can only be obtained. This means that a series of radiographs has to be exposed which in turn means considerable drawbacks, viz on one hand that the patient has to be subject to a many times larger X-ray dosage than should be necessary, on another hand that the patient will have time to move between the different exposures which makes the interpretation of the radiographs more difficult, on a further hand there is no reference point for an adequate distance and angle determination, for example for orthopaedic determinations. Present apparatuses also lead to that no exposure is made under normal load of the spine and the extremities, which is desired in order to establish a diagnosis or to determine the effect of a measure.

Thus there is a problem to be solved viz to be able to obtain a continuous X-ray image using image plates in order to be able to radiograph, for example, a whole leg from foot to the iliac crest to be able to determine e. g., the effect of an orthopaedic

aiding equipment, or the whole spine to e. g., determine the degree of a scoliosis of a patient.

Description of the present invention It has now surprisingly turned out possible to be able to solve this problem by means of the present invention which is characterized in that longitudinal space provided with at least three resting planes for receiving image plates, at least one space for receiving an orientation screen, and optionally a space for receiving a screen gear.

Further characteristics are evident from the accompanying claims.

By means of the present invention it is obtained that at least three image plates can be brought to co-operate for taking a composed radiograph after a digital evaluation.

The present invention will now be described more in detail with reference to a preferred embodiment shown in the accompanying drawing, wherein FIG. 1 shows a front view of a device according to the present invention, and FIG. 2 shows in side perspective view of the device according to Fig. 1.

1 denotes a longitudinal, rectangular composed plate holder, which preferably is prepared of a material, which restricts secondary radiation of an X-ray apparatus, such as carbon fibre reinforced polymer. The plate holder 1 is turnable + 90° on a stand 2 via a central axis 3. The plate holder 1 can be moved vertically in a groove 4 designed in the stand 2, and is thereby supported by gas dampening springs 5 arranged in the stand 2. The stand 2 can be arranged standing by itself on a floor and thereby movable in relation to a patient and an X-ray radiation apparatus, or be fixed to a wall.

The plate holder 1 comprises, as shown in Fig. 2, a first space 6, as seen from the stand 2, which space is divided into three equal sections 6a, 6b, 6c. Each section comprises a resting plane 7, where the lowermost one is the lower edge surface 8 of the plate holder 1, and the remaining two are fixedly arranged intermediate bottoms

7 in the plate holder 1. Each section comprises a lead plate 10 arranged to restrict secondary radiation at lightening using X-rays. In these three sections image plates 11 are arranged to be introduced with some overlap. In front of the image plate space, seen from the stand 2, there is a second space 12 arranged. This second space 12 is intended to receive an orientation screen 13, which in itself has a bar pattern, suitably 50 x 50 mm, which bar pattern will be reproduced on the digital image plate 11 arranged behind the orientation screen at fighting using X-rays. The orientation screen 13 is arranged to be introduced through a slot arranged in the upper edge 14 of the plate holder 1. This is done to guarantee the orientation of the orientation screen 13 with its bar pattern into the plate holder 14.

The orientation screen need not necessarily contain a bar pattern but may contain any other graphic, which provides for an orientation of the different images, which are obtained on the image plates in relation to each other, so that the partial images can be composed to a common image from which measurements can be made, if so desired.

Further in front of the second space 12, seen from the stand 2, there is a third space 15 being arranged. This space is intended to receive a screen gear 16, which is arranged solely for the purpose of restricting secondary radiation from lighting by X- rays. As evident from Fig. 1 there are two recesses 17 in the front side of the space 15, which recesses are arranged to facilitate removal/insertion of the screen gear into the space 15. The screen gear 16 is suitably prepared of a carbon fibre reinforced polymer.

When using the present device image plates are introduced into their spaces 6a, 6b, and 6c, as well as an orientation screen 13 with its bar pattern into the space 12 through the upper edge 14, as well as a screen gear 16 into the space 15 from the side. The patient is placed standing in front of the device and the height of the device is adjusted with regard to what to be radiographed. Then the patient is radiated using only one exposure for 20 msec. Hereby, the patient will not change position and the X-ray dosage will be small.

The exposure takes place under load, as well, which may be essential to determine a diagnosis or to determine the effect of a treatment, as the effect of an orthopaedic instep support on an ankle, knee, and hip. After exposure the image plates are "developed"and with the aid of the bar pattern of the orientation screen 13 the three individual digital images can be composed into one digital image from which a number of parameters can be retrieved, including measurements of angles and lengths (distances).

The plate holder 1 can be made of a carbon fibre reinforced polymer, but can also be made of stainless steel, whereby it then has an open front towards the screen gear and the orientation screen. In the later case a box having a whole bottom plate, and three side planes, and the upper side mechanically reinforcing frame forms the plate holder. One long side is open to be able to introduce image plates and a screen gear therein. The plate holder need not be attached to a stand for the exposure of a standing patient but can be arranged to a rollable stand, which can be introduced beneath a patient's bed, whereby the patient then is placed in such a way that radiopaque parts of the bed or stretcher bottom are avoided.

By being able to rotate the device 90° on the stand the device can be placed along a bed or stretcher, as well, so that the patient can be X-rayed in a reclining position, or that the patients whole pelvic-ilium region can be X-rayed in a standing position.