Positron Emission Tomography (PET) Scanner

Abstract

A positron emission tomography (PET) scanning device 1 is provided, comprising a detector ring 2 for detecting emitted PET radiation and a main support structure 3 to which is attached a U-shaped portion 34 having two arms 341 for holding the detector ring 2 therebetween. The detector ring 2 is held by the two arms 341 such that the detector ring 2 can be rotated about a rotation axis R extending through the U-shaped portion 34, in particular through the two arms 341 of the U-shaped portion 34. The main support structure 3 comprises a guide rail to which the U-shaped portion 34 is attached, such that the U-shaped portion 34 can be displaced along the guide rail, the guide rail extending along a direction inclined with respect to the direction of gravity G.

Description

[Technical field]

[0001] The present invention relates to a positron emission tomography (PET) scanning device that is particularly well adapted to the needs of the subject being scanned. [Background technology]

[0002] Positron Emission Tomography (PET) scanning devices are usually large and bulky and are only available in hospitals or dedicated radiology facilities. Therefore, patients must travel to the PET scanning device to undergo scanning when required. However, patients are often elderly or sick, living in nursing homes, immobile, or bedridden. As a result, travel to the PET scanning site is inconvenient for the patient and often involves a not inconsiderable risk that the patient may develop a complication or contract an infection during the travel. Thus, most current technology PET scanning machines have the disadvantage of not being portable to the subject.

[0003] PET scanning machines also require the patient to assume a certain position on the bed during the scanning procedure, usually lying on their back. Depending on the patient's health condition, this position can be quite straining for the patient and may even compromise the scan results if the patient moves during the scan, for example.

[0004] Furthermore, hospitals, researchers, material scientists, and veterinarians are often unable to make good use of PET machines, not only because they are too large, but also because they often do not fit the needs of applications outside of standard oncology applications, especially in hospital clinics.

[0005] The majority of PET scans concern imaging of the human brain. However, for this purpose, whole-body PET scanners are often used, which have a large aperture to fit the entire body, so the detector elements are placed far from the area to be imaged, resulting in low sensitivity and specificity.

[0006] US Pat. No. 5,399,433 discloses a small, lightweight PET scanner that is portable and can be fixed to a patient's bed.

[0007] Nos. 5,233,393, 5,396,421, 5,433,632 and 5,521,663 disclose a PET detector integrated into a helmet-type brain imager, which is suspended on a moving gantry.

[0008] US Pat. No. 6,399,433 discloses a PET imaging apparatus having an adjustable support table that allows the patient to sit, lie or stand during the imaging procedure.

[0009] The PET scanning device disclosed in US Pat. No. 5,399,633 includes a horizontally positioned, vertically movable detector ring that allows the patient to sit upright in a wheelchair during the scanning process.

[0010] US Patent No. 5,393,633 shows a computed tomography (CT) machine having a gantry body that can be tilted by rotating about an upper horizontally extending axis to enable scanning of patients in both sitting and lying positions.

[0011] US Patent No. 5,393,636 proposes combining a CT machine having a horizontally rotatable gantry assembly with an adjustable scanning support that allows the patient to assume any of a variety of positions during the imaging process.

[0012] US Patent No. 5,399,633 shows a PET imaging device with reduced dimensions, which comprises a number of measurement rings with different diameters, which are slidably mounted on a support structure.

[0013] US Patent No. 5,399,633 discloses a mobile wheeled PET scanner for imaging the human head. Another mobile wheeled PET scanner is disclosed by US Patent No. 5,399,633.

[0014] US Patent No. 5,393,633 discloses a PET scanning device having a detector ring held between two arms suspended via pulleys in the ceiling or via connected rods in the wall or wheelchair.

[0015] No. 6,299,333 relates to an apparatus that combines a virtual reality system with PET brain imaging. A mobile brain imager is suspended on a mobile support that can be carried in the form of a backpack or placed on a wheeled carriage.

[0016] US Patent No. 5,399,633 shows a CT machine having a U-shaped support structure to which two vertically movable holding arms are attached. A rotatable imaging unit is held between the two arms.

[0017] US Patent No. 5,399,633 discloses an apparatus for cone-beam computed tomography having a gimbaled scanner assembly housing a radiation source and a detector, the scanner assembly being movable along a vertical support column. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] US Patent Application Publication No. 2013 / 0218010 [Patent Document 2] International Publication No. 2020 / 015384 [Patent Document 3] U.S. Patent No. 9,226,717 [Patent Document 4] U.S. Patent No. 7,884,331 [Patent Document 5] China Patent Application Publication No. 109864751 [Patent Document 6] U.S. Patent No. 9,833,208 [Patent Document 7] U.S. Patent No. 10,307,120 [Patent Document 8] Japanese Patent No. 3244776 [Patent Document 9] U.S. Patent No. 10,531,843 [Patent Document 10] U.S. Patent No. 9,414,789 [Patent Document 11] US Patent Application Publication No. 2011 / 0315884 [Patent Document 12] U.S. Patent No. 8,735,834 [Patent Document 13] Japanese Patent No. 4642143 [Patent Document 14] US Patent Application Publication No. 2016 / 0166219 [Patent Document 15] Japanese Patent No. 3793320 [Patent Document 16] International Publication No. 2014 / 058772 Summary of the Invention

[0019] It is an object of the present invention to provide a versatile Positron Emission Tomography (PET) scanning device that can be easily adapted to the needs of the subject being scanned.

[0020] This object is solved by a PET scanning device according to claim 1. Further embodiments of the PET scanning device are provided in the dependent claims.

[0021] For the purposes of this specification, height and orientation information such as "top", "bottom", "up", "down", "above", "below" and the like should be understood to refer to the PET scanning device standing upright relative to the direction of gravity and ready to scan human or animal subjects or plants in normal intended use.

[0022] Accordingly, the present invention provides a positron emission tomography (PET) scanning apparatus comprising: a detector ring for detecting the emitted PET radiation; and a main support structure having attached thereto a U-shaped section having two arms for holding the detector ring between the arms; Equipped with The detector ring provides a PET scanning device in which the detector ring is held by the two arms such that the detector ring can be rotated around an axis of rotation extending through the U-shaped portion, and in particular through the two arms of the U-shaped portion.

[0023] The main support structure extends along a direction inclined relative to the direction of gravity and comprises a guide rail to which the U-shaped portion is attached such that the U-shaped portion can be displaced along the guide rail.

[0024] By extending along a direction inclined with respect to the direction of gravity it is meant that the guide rail extends neither parallel to the direction of gravity, i.e. at an angle of 0°, nor perpendicular to the direction of gravity, i.e. at an angle of 90°. Instead, the guide rail extends at an angle of preferably 0°-60°, more preferably 10°-50°, most preferably 20°-40° with respect to the direction of gravity. The inclined extension of the guide rail has the consequence that the U-shaped portion together with the detector ring is displaceable relative to the main support structure along a direction inclined with respect to the direction of gravity.

[0025] The possibility of displacing the detector ring along an inclined or oblique direction with respect to the direction of gravity allows the detector ring to be optimally positioned with respect to the patient to be scanned while the patient is in a comfortable lying or reclining sitting position. Thus, with the present PET scanning device shown, it is not the patient that needs to be positioned with respect to the detector ring, but the detector ring can be positioned so that the image area of ​​interest can be optimally imaged without the need to move the patient. For patients, especially elderly patients, a reclining sitting position has been found to be particularly comfortable during the imaging procedure. This position is a natural position and leads to less patient movement, especially during long imaging sessions. The possibility of displacing the detector ring along an inclined direction allows the detector ring to be positioned along the main longitudinal axis of the upper part of the body of such a positioned patient, and the possibility of rotation allows an optimal orientation of the detector ring with respect to the desired imaging plane.

[0026] Furthermore, the ability to rotate the detector ring relative to the U-shaped portion combined with the ability to displace the U-shaped portion along an inclined direction leads to a high versatility of the PET scanning device. Due to these capabilities, the PET scanning device is not only adapted to scan human patients, in particular the human brain, but also suitable for scanning extremities such as arms and legs and / or for scanning animals or plants. The possibility to rotate and displace the detector ring relative to the main support structure makes the PET scanning device particularly versatile and adaptable for various purposes, for example for scanning rodents or plants. Therefore, it is preferred that the detector ring can be rotated so that its opening can be oriented both in a horizontal position and in a vertical position.

[0027] The provision of a U-shaped section for holding the detector ring allows for a relatively simple construction of the PET scanning apparatus, allowing the detector ring to be both displaced and rotated. The U-shaped section preferably represents the only element that mechanically connects the detector ring to the main support structure.

[0028] The extension of the rotation axis of the detector ring through the two arms provides the advantage that the detector ring can be easily adjusted to the patient's needs by rotation and at the same time held in a particularly stable manner on the main support structure: no unnecessary elements have to rotate together with the detector ring, which makes it possible to reduce the total weight of the rotatable parts and to make the rotation of the detector ring easier for the user.

[0029] In certain embodiments, it is conceivable that the detector ring is not only displaceable together with the U-shaped portion, but also displaceable relative to the U-shaped portion, in particular relative to the two arms. Additional displaceability of the detector ring relative to the U-shaped portion may be provided, for example to allow fine adjustment.

[0030] The detector ring typically comprises a number of sensors, in particular a number of sensor modules, arranged in a circumferential ring for positioning around a patient, for example around the patient's head for detecting PET radiation emitted from the patient's brain. The detector ring preferably forms a closed ring, i.e. a circumferentially closed ring. By forming a closed ring, the sensors can be optimally arranged along the entire inner surface of the detector ring.

[0031] The detector ring usually has a round, for example elliptical or circular, shape at least on its inner surface. Thus, the detector ring usually has a preferably round, in particular circular, opening into which the scanned part of the object is inserted for the PET scan. The outer surface of the detector ring also preferably forms a round, in particular circular, shape. A detector ring having such a shape has a lighter appearance to the user's eye. However, the detector ring may also have an angular, in particular rectangular or square, inner and / or outer shape.

[0032] The detector ring advantageously has at least one handle for facilitating the rotation and displacement of the detector ring for the user. However, the PET scanning device may also have one or several motor units serving to displace and / or rotate the detector ring. In this case, it is conceivable to omit the handle for rotation and displacement.

[0033] In normal use of the present PET scanning apparatus, the main support structure typically carries most, if not all, the weight of the detector ring. Thus, the main support structure typically functions to support and hold the detector ring in a stable position during the scanning procedure. After positioning the main support structure near the subject to be scanned, or vice versa, the detector ring may be rotated and displaced accordingly to adjust the PET scanning apparatus relative to the subject.

[0034] The U-shaped portion is in particular defined by two arms. The two arms are usually connected to one another at one end by a vertically extending connecting portion, which also forms part of the U-shaped portion. The other end of each arm usually forms a free end. The rotation axis extends through the U-shaped portion if it extends through the connecting portion and at least one of the two arms. Preferably, the rotation axis extends through each of the two arms. Particularly preferred are embodiments in which the rotation axis extends perpendicularly to the direction of extension of the two arms, advantageously parallel to the connecting portion. Preferably, a swivel joint is arranged on each of the two arms to allow rotation of the detector ring.

[0035] The two arms and the connecting part preferably define a plane in which the U-shaped part is located. This plane may have a certain thickness. Elements that are not located in this plane, particularly those that extend perpendicularly to this plane, are generally not considered to be part of the U-shaped part, particularly if they are displaceably mounted. The U-shaped part preferably forms a mechanically fixed structural unit of the PET scanning device, i.e. does not include any parts that are movable relative to each other.

[0036] The direction of displacement preferably extends perpendicular to the direction in which the two arms extend, in particular perpendicular to the direction in which the two arms extend from the connection part to their free ends. For this purpose, the two arms of the U-shaped part preferably extend obliquely upwards with respect to the direction of gravity. In order to be optimally adjustable to the desired imaging plane, the detector ring is advantageously displaceable in at least one rotational position in a direction that stands approximately perpendicular to the plane defined by the openings in the detector ring.

[0037] In a particularly preferred embodiment, the main support structure and the U-shaped portion together form a Z-shaped structure, which allows for a particularly stable design of the PET scanning apparatus.

[0038] Preferably, the PET scanning device further comprises a weight compensation device for compensating for the weight of the U-shaped portion and the detector ring in order to facilitate the displacement of the U-shaped portion along the guide rail for the user. For this purpose, the weight compensation device preferably comprises a counterweight connected to the U-shaped portion via a pulley. The pulley may in particular be arranged at the top of the main support structure. The counterweight is preferably arranged on the opposite side of the main support structure to the U-shaped portion. The main support structure may comprise a further guide rail to which the counterweight is attached and may allow the counterweight to be displaced along the further guide rail. The further guide rail preferably extends along a direction inclined to the direction of gravity, in particular parallel to the guide rail to which the U-shaped portion is attached.

[0039] The guide rail to which the U-shaped portion is attached and / or the further guide rail to which the counterweight is attached may each comprise two or more rail elements extending parallel to each other in order to distribute the weight of the U-shaped portion and the detector ring or of the counterweight, respectively.

[0040] A first motor unit may be provided for displacing the U-shaped portion along the guide rail. Alternatively or additionally, a second motor unit may be provided for rotating the detector ring about the axis of rotation. The provision of a first motor unit and / or a second motor unit not only facilitates handling of the PET scanning device for an operator, but also preferably allows the detector ring to be displaced and rotated remotely with respect to the subject to be imaged.

[0041] The PET scanning device preferably comprises a first brake device for preventing undesired displacement of the U-shaped portion along the guide rail. The first brake device thus allows the displacement position of the detector ring relative to the main support structure to be fixed. In a preferred embodiment, the first brake device comprises one or more brake pads attached to the U-shaped portion and adapted to act directly on the guide rail to achieve a braking effect. The first brake device may in particular be an electromagnetically actuated brake device which generates a braking effect when not actuated and releases the braking effect when actuated. Thus, for safety reasons, it is preferably possible to displace the detector ring together with the U-shaped portion only when the first brake device is supplied with current.

[0042] Alternatively or additionally, the PET scanning device may comprise a second brake device for preventing undesired rotation of the detector ring around the rotation axis. The second brake device may thus fix the rotational position of the detector ring relative to the U-shaped part. For this purpose, the second brake device may act, for example, on one or both of the swivel joints at which the detector ring is attached to the U-shaped part in order to generate a braking effect. The second brake device may in particular be an electromagnetically actuated brake device which generates a braking effect when not actuated and releases the braking effect when actuated. Thus, for safety reasons, it is preferably possible to rotate the detector ring only if the second brake device is supplied with current.

[0043] In certain preferred embodiments, the PET scanning apparatus may include wheels attached to the main support structure to make it easier to move the PET scanning apparatus. The wheels allow the PET scanning apparatus to be moved closer to the subject to be scanned, instead of moving the subject closer to the PET scanning apparatus. When wheels are provided for moving the PET scanning apparatus, the apparatus preferably also includes a wheel locking mechanism to avoid undesired movement of the PET scanning apparatus, especially during scanning of the subject.

[0044] The PET scanning device, due to its mobility, also allows in-room monitoring during hadron therapy: for this purpose, the patient can be moved on the treatment support directly to the detector ring, which is preferably positioned at an appropriate height and previously co-aligned with the hadron therapy device, in order not to lose valuable time and signal due to decay of the isotope tracer.

[0045] The rotation axis about which the detector ring can be rotated preferably extends through the center of mass of the detector ring. The detector ring can then be particularly easily rotated by the user and / or by the second motor unit, and the load acting on the structural components is minimized. Particularly preferred is an embodiment in which the rotation axis extends radially through the detector ring. Thus, the detector ring is preferably attached to the two arms of the U-shaped section at two radially arranged positions on its outer surface.

[0046] In order to balance the centre of mass of the detector ring relative to the axis of rotation, the PET scanning apparatus preferably comprises one or more weights movably attached to the detector ring and / or removably attachable to the detector ring.

[0047] In order to be able to position and orient the detector ring with respect to the object to be imaged in an accurate and reproducible manner, the PET scanning device preferably comprises one or more detector encoders, in particular one or more electronic detector encoders, for detecting the displacement position of the U-shaped section along the guide rail and / or the rotation angle of the detector ring around the rotation axis, the electronic detector encoders being preferably connected to a computing device used to perform the acquisition of the PET related data by the detector ring.

[0048] In another equally preferred embodiment, the PET scanning device may comprise a scan support, for example in the form of a seating unit, i.e. a chair or a bed, for carrying the subject to be scanned. The main support structure may, but does not have to be, integrally formed with the scan support. If it is not integrally formed with the main support structure, the scan support preferably comprises positioning means that allow the scan support to be positioned in a well-defined, precise and reproducible manner relative to the main support structure. The scan support is preferably adjustable to the needs of the subject to be scanned. If the scan support is in the form of a seating unit, it preferably comprises a backrest extending parallel to a guide rail along which the U-shaped portion is displaceable.

[0049] The preferably adjustable scan support, in particular the adjustable seat unit, preferably comprises one or more support encoders, in particular one or more electronic support encoders, for detecting the position of the patient. The electronic support encoders are preferably connected to a computing device, which is preferably used to perform the acquisition of the PET-related data by means of the detector ring. If the scan support is not formed integrally with the main support structure and if the computing device is arranged beside the main support structure, then preferably coupling elements are provided for connecting the support encoders to the computing device. The support encoders may for example be adapted to detect the seat height, the headrest height, the backrest height and / or the angle of inclination of one or more of these parts of the seat unit.

[0050] In certain embodiments, the scan support may be adapted to position the patient's breast in the detector ring. Thus, in this case, the scan support is particularly adapted to scan the patient's breast with the sensors of the detector ring. This application is particularly suited to the field of oncology. The scan support preferably includes an opening or a depression, allowing the breast to hang into the opening or rest on the support, respectively, during the PET imaging procedure. Thus, the opening or depression, whichever is applied, is preferably oriented or oriented horizontally with respect to gravity.

[0051] The PET scanning device may additionally comprise an adjustable headrest, which allows the human patient to be in a supine and / or sitting position for the PET scanning procedure. The headrest serves to position and hold the patient's head during the scanning procedure. For this purpose, the headrest is preferably adapted to be placed inside the detector ring, or may be attached to the detector ring or to the scan support.

[0052] The headrest may comprise one or more fixation elements for immobilizing the head, in particular fixation elements that can be used in combination with means for fixation used in stereotactic radiosurgery and hadron beam therapy, including for example a thermoplastic face mask that can be attached to a stereotactic head frame and / or a patient frame.

[0053] The PET scanning device may have an overall profile that tapers downwards from the U-shaped portion along the direction of gravity, in particular when viewed from the front perpendicular to the axis of rotation. Such a design may make the PET scanning device particularly space-saving, since the width of the device is determined primarily by the width of the U-shaped portion required to hold the detector ring, at least in the upper region. At the bottom, the profile of the PET scanning device may widen again along the direction of gravity in order to improve stability.

[0054] The PET scanning apparatus preferably has overall dimensions that allow it to be moved in a normal upright position, at least in one position of the detector ring, through a standard door opening having a width of 98.5 cm or less, in particular 86.0 cm or less. More preferably, if the PET scanning apparatus has wheels, the apparatus has an overall width that allows it to be moved on wheels through a door opening having a width of 98.5 cm or less, in particular 86.0 cm or less.

[0055] The PET scanning device preferably further comprises a computing device for performing the acquisition of PET related data by the detector ring. The computing device typically comprises at least a processor, in particular a central processing unit, and a storage element. Predefined instructions are typically pre-stored in the storage element for instructing the PET scanning device to detect the PET radiation emitted by the detector ring, to securely or at least cache the acquired PET information, and / or to further transmit the information to other devices, for example by a wired or wireless transmission unit. The computing device is preferably integrated in the main support structure.

[0056] Preferred embodiments of the present invention will now be described with reference to the drawings, which are for the purpose of illustrating the preferred embodiments of the present invention and are not intended to limit the present invention. [Brief description of the drawings]

[0057] [Figure 1] FIG. 1 is a schematic side view of a PET scanning apparatus of the invention according to a first embodiment, with a support device in the form of a seating unit. [Diagram 2] FIG. 2 is a schematic side view of the same PET scanning apparatus as in FIG. 1 with a support device that allows imaging of a patient in a supine position. [Diagram 3]FIG. 3 is a schematic side view of the same PET imaging apparatus as in FIG. 1 with a support apparatus for rodent imaging. [Figure 4] FIG. 4 is a schematic side view of the same PET scanning apparatus as in FIG. 1 with another variation of the seating unit. [Diagram 5] FIG. 5 is a schematic side view of a PET scanning apparatus of the present invention according to a second embodiment with the seat unit of FIG. [Figure 6] FIG. 6 is a schematic side view of a PET scanning apparatus of the present invention according to a third embodiment, with a seat unit fixedly attached to a main support structure. [Figure 7] FIG. 7 is a side view of a PET scanning device of the present invention according to a fourth embodiment. [Figure 8] FIG. 8 is a front view of the PET scanning apparatus of FIG. 7 without the detector ring. [Figure 9] FIG. 9 is a rear view of the PET scanning device of FIG. [Figure 10] FIG. 10 is a perspective view of the PET scanning apparatus of FIG. 7 without the detector ring and showing the rotational drive unit. [Figure 11] FIG. 11 is a detailed diagram of the rotary drive unit and rotary brake device of the PET scanning apparatus of FIG. [Figure 12] FIG. 12 is a perspective view of a PET scanning apparatus of the present invention according to a fifth embodiment, without a detector ring. [Figure 13] FIG. 13 is a schematic side view of the same PET scanning apparatus as in FIG. 1, with a support device that allows imaging of a patient's breast while the patient is in a sitting position. [Figure 14] FIG. 14 is a schematic side view of the same PET scanning apparatus as in FIG. 1, with a support device that allows imaging of the patient's breast while the patient is in a supine position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] In figures 1 to 14 several different embodiments of the inventive PET scanning device 1 are shown. Elements which belong to different embodiments but have the same or similar function are provided with the same reference numbers in each case.

[0059] In all the embodiments shown in Figures 1 to 14, the PET scanning device 1 comprises a detector ring 2 having a number of sensors arranged along its circular inner surface which, although not visible in the figures, serve to detect and measure the PET radiation emitted in the area of ​​the opening of the detector ring 2. The detector ring 2 has in each case the basic shape of a ring with circular inner and outer surfaces.

[0060] In all embodiments, the detector ring 2 is arranged between two holding arms 41 that hold the detector ring 2 therebetween. The two holding arms 41 form part of a U-shaped portion 4 that is attached to a main support structure 3. The detector ring 2 is rotatable about a rotation axis R that extends through the two holding arms 41 of the U-shaped portion 4. Furthermore, the detector ring 2 is in all embodiments displaceable together with the U-shaped portion 4 along an inclined direction D relative to the main support structure 3. To facilitate rotation and displacement of the detector ring 2, one or several handles may be attached to the outer surface of the detector ring 2.

[0061] The direction in which the U-shaped portion 4 is displaceable is inclined with respect to the direction of gravity G, meaning that it is neither parallel nor perpendicular to the direction of gravity G. In all embodiments, the U-shaped portion 4 is mounted on guide rails which are provided on the main support structure 3 and which allow the U-shaped portion 4 to be displaced along the aforementioned inclined direction D. The guide rails thus also extend along an inclined direction.

[0062] The axis of rotation R extends along the horizontal direction, i.e. perpendicular to the direction of gravity G. Furthermore, the axis of rotation R extends perpendicular to the direction in which the U-shaped part 4 can be displaced. The direction of displacement D is approximately perpendicular to the longitudinal extension of the holding arm 41.

[0063] In the first embodiment shown in Fig. 1, the main support structure 3 comprises a lower vertical portion and an upper inclined portion. The U-shaped portion 4 is attached to the top of the upper inclined portion of the main support structure 3 such that the U-shaped portion 4 is displaceable along the entire length of the upper inclined portion. Two retaining arms 41 of the U-shaped portion 4 serve to hold the detector ring 4 therebetween. For this purpose, two fixing lugs 22 are attached to the outer surface of the detector ring 2. The fixing lugs 22 are provided on diametrically opposite sides of the detector ring 2. The fixing lugs 22 engage in through holes in each of the retaining arms 41.

[0064] The engagement of each fixing lug 22 with the respective through hole is such that rotation of the detector ring 2 is possible about a rotation axis R. The rotation axis R is defined by the positions of the fixing lugs 22. Thus, the rotation axis R extends through the centre of each of the two fixing lugs 22 and through each of the retaining arms 41. With respect to the detector ring 2, the rotation axis R extends radially through the ring, preferably through the centre of mass of the detector ring 2.

[0065] To carry out the acquisition of the PET images, a computing device 5 is housed within the main support structure 3. The transmission of data and / or energy to or from the computing device 5 may take place via one or several cables and / or wirelessly. In other embodiments, the computing device 5 may be located externally. The computing device 5 is preferably connected by a cable or wirelessly to a user input / output device. The user input / output device may for example take the form of an external personal computer or may be a display, in particular a display with a touch screen, attached to the PET scanning device.

[0066] The scan support 6 is provided for supporting a human patient in an inclined sitting position during the scanning procedure. The scan support 6 may be, but does not have to be, part of the PET scanning device 1. Prior to image acquisition, the patient is placed on the scan support 6 with the detector ring 2 in its uppermost position on the main support structure 3. The detector ring 2 is then rotated and displaced by medical personnel using the handle(s) (not shown in FIG. 1 ) into an optimal position for image acquisition.

[0067] The scan support 6, in the form of a chair-type seat unit, comprises a base structure 61, which supports a seat base 62 and a leg support 63 for supporting the patient's legs during the scan procedure. The base structure 61 also has an inclined back support 64 attached thereto. On the upper side of the back support 64, a backrest 65 and pivotable (see arrows in FIG. 1) armrests 67 are attached. The backrest 65 can be displaced along the back support 64 (double arrow in FIG. 1) to optimally seat the patient during the PET scan procedure. At the upper end, a headrest 66 is attached to the backrest 65, which allows displacement of the headrest 66 along the longitudinal direction of the backrest 65 (double arrow in FIG. 1) to further adjust the scan support 6 to the patient. For image acquisition, the patient's head is placed on the headrest 66 and the detector ring 2 is displaced and rotated so that the patient's head is located inside the detector ring 2. Thus, the headrest 66 is likewise positioned inside the detector ring 2 during the imaging process.

[0068] The displacement direction D of the detector ring 2 is defined by the longitudinal extension direction of the guide rails (not shown in FIG. 1 ) attached to the main support structure 3, and corresponds approximately to the longitudinal extension direction of the back support 64 and the backrest 65, and the direction in which the back support 64 and the backrest 65 can be displaced. Thus, when the patient is seated on the scan support 6 as intended and ready for the scan procedure, the displacement direction D of the detector ring 2 corresponds to the main longitudinal axis of the upper part of the patient's body. A head strap may be used to prevent the patient from moving his / her head during the acquisition of images.

[0069] In the embodiment of Fig. 1, the scan support 6 is separated from the rest of the PET scanning device 1, in particular from the main support structure 3. The main support structure 3 of the PET scanning device 1 comprises a base structure 32 to which wheels 33 are attached. By means of the wheels 33, the PET scanning device 1 can be moved in order to move it to the patient. The scan support 6 does not have wheels here. Thus, the location of the scan support 6 is fixed, which has the advantage that the external parameters and conditions for the scanning procedure are well-defined and known. In such a setup, the PET scanning device 1 can for example be used in combination with one or more such scan supports 6 in order to use the same PET scanning device 1 for performing PET scans in several designated locations, for example in a hospital or a care home. Preferably, positioning means are provided that allow the main support structure 3 to be positioned in a well-defined, precise and reproducible manner relative to the scan support 6.

[0070] 1, the U-shaped portion 4 and the main support structure 3, including the base structure 32, together form a Z-shaped structure. This shape optimizes the stability of the PET scanning device 1.

[0071] The two holding arms 41 of the U-shaped portion 4 are connected at one end by a connecting part, referred to herein as a holding base 42. From the holding base 42, the two holding arms 41 extend parallel to each other in a diagonal upward direction with respect to the direction of gravity G. The holding base 42 extends perpendicularly to the two holding arms 41. During the acquisition of a PET scan image, the patient's head is located in the area between the two holding arms 41.

[0072] Figure 2 shows the use of the same PET scanning device 1 as in Figure 1 in combination with a scan support 6, here in the form of a bed. The PET scanning device 1 can thus not only be used to scan a patient in a sitting position, as shown in Figure 1, but also to scan a patient in a lying position, as shown in Figure 2. Due to its displaceability and rotatability relative to the main support structure 3, the detector ring 2 can be optimally positioned in each case.

[0073] In Fig. 3, the same PET scanning device 1 as in Fig. 1 is used to scan a rodent, in this case a mouse M. As in the case of Fig. 2, for this purpose the detector ring 2 is displaced to a lower position relative to the main support structure 3 and rotated about an axis or rotation R in a vertical position. This position and orientation of the detector ring 2 makes it possible to move the rodent to be scanned completely from one side to the other through the opening of the detector ring 2. The height adjustment and rotatability of the detector ring 2 not only allows the PET scanning device 1 to be optimally adjusted to the scanning situation, but also allows it to be stored in a particularly space-saving manner.

[0074] Figure 4 again shows the same PET scanning apparatus as in Figure 1, but now with another variation of the scan support 6. In this case, instead of the backrest 65 and headrest 66, the seat base 62 and leg support 63 are height adjustable.

[0075] Figure 5 shows a PET scanning device 1 according to a further embodiment, which differs from that of figure 1 in that it does not have wheels. The PET scanning device 1 is thus designed here as stationary. Alternatively, the PET scanning device 1 may have wheels in order to be mobile, or may be stationary, as in the case of figure 5.

[0076] The scan support 6 shown in Fig. 5 comprises encoders in the form of a backrest position encoder 651 and a headrest position encoder 661 for detecting and measuring the position of the patient relative to the PET scanning device 1, in particular relative to the main support structure 3. The backrest position encoder 651 is adapted to detect the position of the backrest 65 relative to the back support 64, and the headrest position encoder 661 is adapted to detect the position of the headrest 66 relative to the backrest 65. The two encoders 651 and 661 are preferably connected to the computing device 5 by cable or wirelessly. To enable data transfer between the encoders 651, 661 and the computing device 5, in case the computing device 5 is arranged in the main support structure 3, a coupling may be provided in the area where the base structure 61 of the scan support 6 contacts the base structure 32 of the main support structure 3. Encoders for detecting the position of the object to be scanned on the scan support may of course also be provided in all other embodiments.

[0077] Figure 6 shows another embodiment of the PET scanning device 1, in which the main support structure 3 is made integral with the scan support 6. This embodiment has the advantage that the relative positions of the main support structure 3 and the scan support 6 are well defined and cannot be changed.

[0078] Figures 7 to 11 show a further particularly preferred embodiment of the PET scanning device 1. In the views of Figures 7, 8 and 10 a guide rail 31 of the main support structure 3 is shown, along which the U-shaped portion 4 can be displaced. The guide rail 31 is present in all the embodiments of Figures 1 to 14, but is not necessarily shown, and here comprises two rail elements running parallel (see Figures 8 and 10). The guide rail 31 defines the direction of displacement of the U-shaped portion 4.

[0079] To facilitate the displacement of the U-shaped portion 4, a weight compensation device 7 is provided. The weight compensation device 7 includes a counterweight 71, which is connected to the U-shaped portion 4 by a cable 74 via a pulley 73. The pulley 73 is arranged on the upper part of the main support structure 3 and guides the cable 74 from the U-shaped portion 4 to the counterweight 71. The counterweight 71 preferably has approximately the same weight as the entire displaceable unit form of the U-shaped portion 4 and the detector ring 2. In this embodiment, the counterweight 71 is attached to the rear side of the main support structure 3 by a guide rail 72 (see FIG. 9). Thus, the counterweight 71 is displaceable along the guide rail 72, which extends parallel to the guide rail 31 along which the U-shaped portion 4 is displaceable. Similar to the guide rail 31, here the guide rail 72 also includes two rail elements extending parallel to each other.

[0080] The counterweight 71 and pulley 73 as well as further parts of the PET scanning device 1 are preferably covered by a cover for design and safety reasons, however, for purposes of illustration the cover has been removed in the views of Figures 7 to 11 and in Figure 12.

[0081] A weight compensation device 7, such as the one shown in Figures 7 to 10, is preferably present in all embodiments shown in Figures 1 to 11. Of course, it is also conceivable that no weight compensation device is provided, or that a weight compensation device is present but not based on counterweights and pulleys. Instead, a weight compensation device based on, for example, a gas pressure spring may be provided.

[0082] In order to prevent undesired displacements or rotations of the detector ring 2, in particular during the scanning procedure, a braking device for preventing undesired displacements of the U-shaped portion 4 along the guide rail 31 and a braking device for preventing undesired rotations of the detector ring about the axis of rotation are preferably provided in all embodiments. The braking device is preferably an electromagnetically actuated device so that it can be automatically operated by the computing device 5. The computing device 5 may in particular be adapted to prevent displacements and rotations of the detector ring 2 during the acquisition of images.

[0083] In the embodiment of Figures 7 to 11, a displacement brake device 43 for preventing undesired displacement of the U-shaped portion 4 is fixedly attached to the U-shaped portion 4 such that its braking element can act directly on the guide rail 31 (see Figure 8).

[0084] A rotation braking device 44 for preventing undesired rotation of the detector ring 2 is shown in figure 10 and in particular in a detailed view in figure 11. The rotation braking device 44 is arranged on one or both of the retaining arms 41 and comprises a braking element which in each case acts on a toothed belt 451 which connects the fixed lug 22 with a drive wheel 452 which is also arranged on the retaining arm 41. By blocking the movement of the toothed belt 451, the rotation braking device 44 makes it possible to prevent a rotation of the detector ring 2.

[0085] To facilitate the displacement and rotation of the detector ring 2 for the user, a handle 21 is provided on the outside of each fixed lug 22. The handle 21 may comprise a switch that actively enables the displacement and rotation, i.e. operates the brake devices 43 and 44 to enable the displacement and / or rotation of the detector ring 2. Additionally or alternatively, for example, one or more handles may be provided directly on the detector ring 2.

[0086] The movement of the detector ring 2 relative to the main support structure 3 may in all embodiments be further facilitated for the user by a displacement drive unit and / or a rotation drive unit. FIG. 11 shows a rotation drive unit 45 with drive wheels 452. The drive wheels 452 can be driven by a motor 453, which is not visible in FIG. 11 but is visible in FIG. 12. The rotation of the toothed drive wheels 452 is transmitted to the fixed lugs 22 by means of toothed belts 451. By rotating the fixed lugs 22, the detector ring 2 is rotated about the rotation axis R. For design and safety reasons, the inner surface of the holding arm 41 is preferably provided with a cover to cover the rotation drive unit 45. However, for the purpose of illustration, these covers are removed in FIGS. 10 to 12.

[0087] A displacement drive unit may be provided, although it is not visible in Figures 8 to 12. For example, a pulley 73 may be driven, or one or more additional cables may be attached to the U-shaped portion 4 and wound around a spool connected to a motor. Rotating the one or more spools may then pull the U-shaped portion 4 upwards or downwards. The displacement drive unit 34 having a worm shaft 341 is further described below with respect to Figure 12.

[0088] A detector displacement encoder 46 is preferably provided in all embodiments to detect the position of the U-shaped portion 4 along the guide rail 31. In the embodiment of Figures 8 to 12, the detector displacement encoder 46 is attached to the U-shaped portion 4, as can be seen in Figure 8.

[0089] In all embodiments a detector rotation encoder 47 is preferably provided to detect the angle of rotation of the detector ring 2 about the rotation axis R. In the embodiment of Figures 8 to 12 the detector rotation encoder 47 is provided on one of the fixed lugs 22, as can be seen in Figure 11.

[0090] The detector displacement encoder 46 and the detector rotation encoder 47 are preferably connected to the computing device 5 by cable or wirelessly.

[0091] FIG. 9 also shows the provision of a balance weight 23 attached to the detector ring 2. The balance weight 23 serves to balance the detector ring 2 such that the axis of rotation extends through the center of mass of the detector ring 2. For this purpose, the balance weight 23 may be movable, for example along the circumference of the detector ring 2, and / or may be removably attachable to the detector ring 2, meaning that it can be removed from the detector ring 2 if necessary. The balance weight 23 may be attached to the inner surface and / or to the outer surface or any other part of the detector ring 2. Naturally, the provision of a balance weight in the detector ring is possible in all other embodiments, even if not shown in the figures.

[0092] 12 shows another embodiment of the PET scanning device 1 without a weight compensation device. By not having a counterweight for the U-shaped portion 4 and the detector ring 2, the PET scanning device 1 can be made lighter.

[0093] To displace the U-shaped portion 4, the embodiment of Fig. 12 has a displacement drive unit 34 with a worm shaft 341. A motor 342 is provided as a drive for rotating the worm shaft 341 about its longitudinal central axis. The worm shaft 341 engages with a threaded element (not visible in Fig. 12) of the U-shaped portion 4 such that rotation of the worm shaft 341 results in displacement of the U-shaped portion 4 along the guide rail 31. The worm shaft 341 also serves to prevent undesired displacement of the U-shaped portion 4.

[0094] In Fig. 13 the same PET scanning device 1 as in Fig. 1 is shown. The PET scanning device 1 is here used to image the breast of a female patient P. PET scanning can be used in particular in the field of oncology, i.e. to detect and / or measure cancerous tissue in the patient's breast PB. For this purpose the patient P sits on a scan support 6 in the form of a seat unit during the acquisition of images. The seat unit comprises a breast support 68 which can be attached for example to the backrest 65 and serves to support the patient's breast PB during the PET scanning procedure. For the PET scan the breast support 68, on which the patient's breast is placed, is inserted into an opening in the detector ring 2. The detector ring 2 is preferably rotated for this purpose to a vertical orientation and displaced into a position below the main support structure 3, as shown in Fig. 13. The breast support 68 does not necessarily have to be attached to a separate part of the scan support 6, but may alternatively form a separate part of the scan support 6. For example the breast support 68 may take the form of an insert which can be attached inside the detector ring 2. In another embodiment, the breast support 68 may be attachable to the upper body of the patient P. In either case, the breast support 68 may have a recess to ergonomically receive the patient's breast PB.

[0095] Figure 14 shows another embodiment in which the scan support 6 is also adapted to scan the breast of a patient P. However, the patient P is now in a prone position during image acquisition. The scan support 6 includes an opening or recess that allows the patient's breast PB to hang / extend into the horizontally oriented detector ring 2 for the PET scan, as shown in Figure 14.

[0096] The invention is of course not limited to the described embodiment and the embodiment shown in figures 1 to 14. The elements shown with respect to the various embodiments in figures 1 to 14 can of course be interchanged and combined between the embodiments, and many modifications are possible. Features shown only with respect to one particular embodiment can also be advantageously provided in other embodiments. For example, the counterweight 71 is not necessarily arranged on the opposite side of the main support structure 3 with respect to the U-shaped portion 4, but may be arranged on the same side of the main support structure 3 or inside it. Wheels for facilitating the movement of the PET scanning device may be provided in all embodiments, but may also be omitted. The guide rail for guiding the U-shaped portion 4 may comprise only a single rail element or may comprise three or more rail elements. The U-shaped portion 4 may be displaceable and / or rotatable by hand, i.e. by muscle force, instead of being driven. The scan support 6 is not necessarily provided. Several further modifications are also possible. [Explanation of symbols]

[0097] 1 PET Scanner 2 Detector Ring 21 Handle 22 Fixed lug 23 Balance weight 3 Main support structure 31 Guide rail 32 Base Structure 33 wheels 34 Displacement drive unit 341 Worm shaft 342 Motor 4 U-shaped part 41 Holding Arm 42 Holding Base 43 Displacement brake device 44 Rotary brake device 45 Rotational drive unit 451 Toothed Belt 452 Driving Wheel 453 Motor 46 detector displacement encoder 47 Detector Rotation Encoder 5 Computing equipment 6 Scan Support 61 Base Structure 62 Seat Base 63 Leg support part 64 Back support 65 Backrest 651 Backrest Position Encoder 66 Headrest 661 Headrest Position Encoder 67 Armrest 68 Breast support part 7 Weight compensation device 71 Counterweight 72 Guide rail 73 Pulley 74 Cable M Mouse P patient Breasts of PB patients R rotation axis D Displacement direction G Gravity direction

Claims

1. A positron emission tomography (PET) scanning device (1), comprising: a detector ring (2) for detecting the emitted PET radiation; a main support structure (3) having a U-shaped section (34) attached thereto having two arms (341) for holding the detector ring (2) between the arms (341); Equipped with the detector ring (2) is held by the two arms (341) in such a way that the detector ring (2) can be rotated about a rotation axis (R) extending through the U-shaped portion (34), in particular through the two arms (341) of the U-shaped portion (34); said main support structure (3) comprising a guide rail to which said U-shaped portion (34) is attached so that said U-shaped portion (34) can be displaced along said guide rail; The guide rail extends along a direction inclined with respect to the direction of gravity (G). The PET scanning device.

2. 2. The PET scanning device (1) according to claim 1, wherein the main support structure (3) and the U-shaped portion (34) together form a Z-shaped structure.

3. 3. The PET scanning device (1) according to claim 1 or 2, further comprising a weight compensation device for compensating for a weight of the U-shaped portion (34) and the detector ring (2) to facilitate displacement of the U-shaped portion (34) along the guide rail for a user.

4. 4. The PET scanning device (1) according to claim 3, wherein the weight compensation device comprises a counterweight connected to the U-shaped portion (34) via a pulley, preferably positioned on the opposite side of the main support structure with respect to the U-shaped portion (34).

5. 5. The PET scanning device (1) according to claim 4, wherein the counterweight is attached to a further guide rail along which the counterweight can be displaced.

6. 3. The PET scanning device (1) according to claim 1 or 2, wherein a first motor unit is provided for displacing the U-shaped portion (34) along the guide rail.

7. 3. The PET scanning device (1) according to claim 1 or 2, wherein a second motor unit is provided for rotating the detector ring (2) around the axis of rotation (R).

8. 3. The PET scanning device (1) according to claim 1 or 2, further comprising a first brake device for preventing undesired displacement of the U-shaped portion (34) along the guide rail.

9. 9. The PET scanning device (1) according to claim 8, wherein the first braking device is an electromagnetically actuated braking device which generates a braking effect when not actuated and releases said braking effect when actuated.

10. 3. The PET scanning device (1) according to claim 1 or 2, further comprising a second brake device for preventing undesired rotation of the detector ring (2) around the rotation axis (R).

11. 11. The PET scanning device (1) according to claim 10, wherein the second braking device is an electromagnetically actuated braking device which generates a braking effect when not actuated and releases said braking effect when actuated.

12. 3. The PET scanning device (1) according to claim 1 or 2, wherein the axis of rotation (R) about which the detector ring (2) can be rotated extends through the center of mass of the detector ring (2).

13. 3. The PET scanning device (1) of claim 1 or 2, further comprising one or more weights movably attached to the detector ring (2) and / or removably attachable to the detector ring (2) for balancing the center of mass of the detector ring (2) relative to the rotation axis (R).

14. 3. The PET scanning device (1) according to claim 1 or 2, wherein the two arms (341) of the U-shaped portion (34) extend obliquely upwards with respect to the direction of gravity (G).

15. 3. The PET scanning device (1) according to claim 1 or 2, wherein the PET scanning device (1) is provided with one or more detector encoders, in particular one or more electronic detector encoders, for detecting the displacement position of the U-shaped portion (34) along the guide rail and / or the rotation angle of the detector ring (2) around the rotation axis (R).

16. 3. The PET scanning device (1) according to claim 1 or 2, further comprising a scan support (6) which enables a subject to be scanned, preferably a human patient (P), to be positioned, preferably in a sitting or lying position, relative to the detector ring (2) for a PET scan procedure, the scan support (6) comprising one or more support encoders, in particular one or more electronic support encoders, for detecting the position of the patient.

17. 17. The PET scanning device (1) according to claim 16, wherein the scan support (6) is adapted to position a patient's breast (PB) within the detector ring (2).

Images