The invention also relates to a method of positioning the arms of patients who are to undergo a supine scanning examination, such as a CT scan- ning.

In connection with e. g. three-dimensional (3D) imaging of patients in scan- ning systems using ionized radiation, such as X-ray, PET (Positron Emitting Thomography) or SPECT (Single Photon Emission Computerized Thomo- graphy), the position of the arms frequently involves problems.

If the patients'arms are disposed along the body, the bones in the arms will reduce the quality of the 3D images which are created of the body in the thorax region.

The image deterioration is primarily caused by attenuation and spreading, including Compton spreading of the radiation, particularly in the bone parts of the arms.

To avoid this image deterioration, the patients are normally placed in the scanners with their arms raised above their heads.

Many patients, including the elderly or traumatized persons, cannot, or can only with difficulty, go through a scanning with their arms raised above their heads, which is a great problem in clinical practice. Frequently, the position of the arms above the patient's head is also complicated by the presence of connected catheters and measuring equipment, e. g. in case of traumatized

road victims.

US Patent No. US 6101650 discloses a method and a device where the patient's arms are placed in their respective holders, so that the patient's arms are positioned along the body from the shoulder toward the feet where the elbows are positioned below the thorax region.

By placing the elbows below the thorax region, the patient's width, however, becomes a problem, as the opening in scanner systems is normally re- duced to a minimum for image technological reasons. The technique ac- cording to the US patent therefore gives many problems in practice and cannot be used at all in connection with patients who are over a certain physical size.

Accordingly, an object of the invention is to improve the prior art and to pro- vide a method of positioning patients'arms in connection with supine scan- nings.

The object of the invention is achieved by an arm pad of the type defined in the introductory portion of claim 1, which is characterized in that the pad holds the patient's arms along the body from the shoulder toward the legs with the elbows raised above the surface of the thorax.

Thus, it is hereby possible to reduce the image deterioration from the arms in images which are to be made of the thorax region, without increasing the width of the patient, in relation to the prior art where the arms are lifted above the head during the scanning.

Other expedient embodiments of the arm pad are defined in claims 2-6.

As mentioned, the invention also relates to a method.

This method is characterized in that the arms are positioned along the body from the shoulder toward the legs with the elbows raised above the surface of the thorax.

It is hereby possible to perform scannings, such as 3D scannings, of supine patients, without the patients having to have their arms lifted above their heads during the scanning, while maintaining the image quality of the inte- rior of the thorax.

As stated in claim 8, it is moreover characteristic of the method that the po- sition of the arms is supported by an arm pad according to one or more of claims 1-6.

The invention will now be explained more fully with reference to the draw- ing, in which Fig. 1 shows a patient placed on a bed prior to a CT scanning. A pad in which the arms may be placed, is arranged above the patient's thorax re- gion.

Fig. 2 shows the patient from fig. 1 with the arms placed on the pad which is supported on each side of the thorax. The arms are placed such that the elbows are raised above the thorax.

Fig. 3 shows an arm pad for CT scanning.

Fig. 4, like fig. 3, shows an arm pad for CT scanning, but seen in another perspective.

Fig. 1 shows a supine patient 1 who is to be scanned in a CT scanner 3.

The patient's arms are raised above the head, which is the approach gen-

erally used in the past. A pad 4 is placed above the patient's thorax, said pad being provided with hollows at the top in which the patient's arms may be placed, and belts 6 which may be attached to a counter part 5, e. g. in the form of a Velcro closure, by means of which the patient's arms may be fixed.

Fig. 2 shows the patient 1 on the examination bed 2 with the arms 8 placed in the arm pad 4 and fixed with a closure 7. As will appear from fig. 2, the patient's arms 8 are raised above the thorax region by the support of the pad 4. The pad 4 is supported at the bottom on each side of the patient's thorax, and the small physical extent of the pad allows the total width of the patient to be kept within the measure which can be placed in the opening of CT scanners.

In the situation shown in fig. 2, the patient 1 is ready to be moved into the opening of the CT scanner and thereby ready to start the scanning exami- nation.

Fig. 3 shows an example of an arm pad 4 made in accordance with the present invention. The arm pad is supported at the bottom on each side of the patient's thorax. The pad curves like an arch from the support faces 9, which gives room for the patient's thorax. The patient's arms may be placed in the depressions 10 and be fixed with the belt 7, which may be secured by e. g. a Velcro closure.

The arm pad will typically be made of a core of a polymeric material, such as foam rubber, with insignificant attenuation of the radiation type used for the scanning. The surface of the arm pad may be made of a material which is easy to clean, and which must be capable of tolerating the cleaning agents, such as spirit, required for the examination spot. A typical selection of material for the surface may e. g. be a polymer, such as PVC.

Fig. 4 shows the same arm pad as fig. 3, but seen in another perspective.

In addition to reducing the discomfort for the patients during a CT scanning, as the patients are not forced to have their arms raised above their heads, but may have their arms placed more naturally along the body and com- fortably supported by an arm pad, with maintained high image quality, the invention has other important advantages over the prior art.

The arm pad facilitates the entire patient handling process, in particular for traumatized patients, which significantly reduces the total time which is to be spent on the scanning. Frequently, the time factor is of great importance precisely for trauma patients, so that a reduction of the scanning time may be a matter of life and death in critical situations.

Experience from the use of the arm pad in accordance with the present in- vention shows that the scanning time for trauma patients is reduced from typically 20-25 minutes to less than 10 minutes by the use of the arm pad.

Although the invention has been explained in connection with an arm pad for e. g. CT scannings, nothing prevents the principles of the invention from being applied in other connections within the scope defined by the claims.