An EMI shielded end cap for an EMI shielded housing

Abstract

A case for shielding electromagnetic interference (EMI). The case includes an EMI shielded enclosure having a plurality of walls and at least one open end, wherein the walls define an interior cavity, and wherein an interior surface of at least one of the walls includes a conductive edge segment at the open end. The case further includes an end cap detachably attached to the open end, a conductive foil element having a sliding contact, and a resilient conductive EMI gasket between the end cap and the foil element. The sliding contact and the EMI gasket are folded such that the sliding contact is between the EMI gasket and the edge segment, wherein the sliding contact makes electrical contact with the edge segment, and the EMI gasket is biased to urge the sliding contact toward the edge segment to maintain the electrical contact.

Description

Technical Field

[0001] Various aspects of the present invention relate to a housing for shielding electromagnetic interference (EMI), and more particularly, to a housing comprising an EMI shielding housing, at least one end cap, a conductive foil element having a sliding contact, and a resilient and conductive EMI pad located between the end cap and the foil element, wherein the sliding contact and the EMI pad are folded such that the sliding contact is located between the EMI pad and an edge segment of the housing, wherein the sliding contact forms an electrical contact with the edge segment, and the EMI pad is biased to push the sliding contact toward the edge segment to maintain the electrical contact. Background Technology

[0002] Magnetic resonance / positron emission tomography (MR / PET) imaging systems are hybrid diagnostic systems that incorporate two distinct imaging modalities. The integration of MR and PET imaging systems requires housing the PET detector within the MRI system volume. The available space within an integrated MR / PET system presents significant challenges for both cost and performance, with components often vying for optimal placement. Both the MRI system's radio frequency (RF) system and the PET system components require electromagnetic shielding to protect against or prevent electromagnetic interference (EMI) generated during MR / PET imaging system operation. PET system components, such as PET detectors with silicon photomultiplier tubes (SiPMs), lutetium oxysilicate (LSO)-based scintillation crystals, and associated detector electronics (DEA), can be housed in an EMI-shielded enclosure.

[0003] EMI enclosures include resealable openings or notches within the enclosure to provide access for periodic maintenance of the electronic components located inside. Current sealing configurations use a combination of gaskets, copper-plated plastic, and adhesive foil to seal the EMI enclosure. Research has found that such sealing configurations are unreliable, costly, and have undesirable side effects, partly due to the large, continuous metal surface constructed during shielding. This metal surface can induce eddy currents, which can lead to unwanted heating, vibration, and ghosting artifacts in images generated by MR / PET systems. Ideally, the technique used to reseal or close the openings should be repeatable and reliable, providing the same EMI shielding effectiveness as the rest of the enclosure. Summary of the Invention

[0004] A housing for shielding electromagnetic interference (EMI) is disclosed. The housing includes: an EMI shielding enclosure having multiple walls and at least one open end, wherein the walls define an internal cavity, and wherein the inner surface of at least one wall includes a conductive edge segment located at the open end. The housing also includes: an end cap removably attached to the open end; a conductive foil element having a sliding contact; and a resilient and conductive EMI gasket located between the end cap and the foil element. The sliding contact and the EMI gasket are folded such that the sliding contact is located between the EMI gasket and the edge segment, wherein the sliding contact forms electrical contact with the edge segment, and the EMI gasket is biased to push the sliding contact toward the edge segment to maintain the electrical contact.

[0005] Additionally, a method for shielding an enclosure to protect against electromagnetic interference (EMI) is disclosed. The method includes providing an EMI shielding enclosure having multiple walls and at least one open end, wherein the walls define an internal cavity and the open end includes an end surface. The method further includes providing a conductive edge segment at the open end and on the inner surface of at least one wall, and providing an end cap removably attached to the open end, wherein the end cap includes a flange. Additionally, the method includes providing a conductive foil element with a sliding contact, and a conductive, resilient EMI gasket located between the end cap and the foil element, wherein the foil element forms electrical contact with the EMI gasket. Furthermore, the method includes inserting the end cap into the open end, wherein contact between the sliding contact and the end surface causes the sliding contact and the EMI gasket to fold, such that the sliding contact is positioned between the EMI gasket and the edge segment, wherein the sliding contact forms electrical contact with the edge segment to provide EMI shielding, and the EMI gasket is biased to push the sliding contact toward the edge segment to maintain electrical contact.

[0006] Those skilled in the art can apply the corresponding features of the present invention in any combination or sub-combination. Attached Figure Description

[0007] Exemplary embodiments of the present invention are further described below in conjunction with the accompanying drawings, wherein:

[0008] Figure 1 A housing is depicted that provides electromagnetic interference (EMI) shielding for PET imaging system components.

[0009] Figure 2 This is an enlarged view of the first end of the EMI housing, where the first end cap is not shown, to depict the first open end.

[0010] Figure 3 yes Figure 1 An enlarged view of the first end of the EMI housing shown.

[0011] Figure 4This is a partial sectional view of a first embodiment of the first end cap and the second end cap, shown in an exploded view (left) and an assembled view (right).

[0012] Figure 5 It is along Figure 4 A 5-5 sectional view of the first end cap of the first embodiment.

[0013] Figure 6 This is a partial sectional view of a second embodiment of the first and second end caps, shown in an exploded view (left) and an assembled view (right).

[0014] Figure 7 This is a partial sectional view of a third embodiment of the first and second end caps shown in an exploded view (left) and an assembled view (right).

[0015] Figure 8 This is a partial cross-sectional top view of the EMI housing and the first end cap of the third embodiment.

[0016] Figure 9 yes Figure 8 A perspective view of the power cable shown.

[0017] Figure 10 This is an exploded view of an exemplary first end of an EMI enclosure.

[0018] Figure 11 This is a front view of a magnetic resonance / positron emission tomography (MR / PET) imaging system. Detailed Implementation

[0019] Although various embodiments incorporating the teachings of this disclosure have been shown and described in detail herein, those skilled in the art will readily devise many other different embodiments that still incorporate these teachings. The scope of this disclosure is not limited to the application of the construction details and component arrangements of the exemplary embodiments set forth in the specification or illustrated in the drawings. This disclosure covers other embodiments and can be practiced or performed in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes only and should not be considered limiting. The use of “comprising,” “including,” or “having,” and variations thereof herein is intended to cover the items listed thereafter and their equivalents, as well as additional items. Unless otherwise specified or limited, the terms “installation,” “connection,” “support,” and “coupling,” and variations thereof, are used broadly and cover direct and indirect installation, connection, support, and coupling. Furthermore, “connection” and “coupling” are not limited to physical or mechanical connections or couplings.

[0020] This invention is applicable to any electromagnetic interference (EMI) shielding enclosure, such as EMI shielding enclosures used in magnetic resonance / positron emission tomography (MR / PET) imaging systems. See also Figure 1 The diagram shows a housing 10 that provides EMI shielding for PET imaging system components (EMI housing 10). The EMI housing 10 is made of at least one conductive material (such as carbon fiber) to provide EMI shielding, but other materials or combinations of materials may also be used. The shape and dimensions of the EMI housing 10 are also designed to provide EMI shielding properties. The EMI housing 10 extends along a longitudinal axis 12 and includes a first end 14 and a second end 16, each having a first EMI shielding end cap 18 and a second EMI shielding end cap 20, respectively. See also... Figure 2 An enlarged view of the first end 14 of the EMI housing 10 is shown to depict the first open end 15, wherein the first end cap 18 is not shown. In one embodiment, the EMI housing 10 includes an upper wall 22 and a lower wall 24, and a transverse left side wall 26 and a right side wall 28 to form a generally rectangular cross-section defining an internal cavity 30. The upper wall 22, lower wall 24, left side wall 26, and right side wall 28 terminate at a first end surface 58 and a second end surface 60 at the first end 14 and the second end 16, respectively, with the end surfaces perpendicular to the longitudinal axis 12. The inner surface 32 of the upper wall 22, lower wall 24, left side wall 26, and right side wall 28 includes a first edge segment 34 located at the first open end 15, the first edge segment 34 including a conductive material 36 (such as an embedded metal strip or insert) to enhance conductivity. Alternatively, the first edge segment 34 may be coated with metallic paint or polished to expose carbon fibers. The second edge segment 38 located at the second opening end 40 of the EMI housing 10 is treated similarly to the first edge segment 34, including coating with a conductive material, metallic paint, or polishing. In one embodiment, the EMI housing 10 can be used as a waveguide when the length of the EMI housing 10 is at least three times the longest sidewalls 22, 24, 26, 28 of the rectangular cross-section, no conductors or metal structures pass through or reside within the EMI housing 10, and the electronics within the EMI housing 10 are not located in the designated waveguide region. Furthermore, the EMI housing 10 can be configured to provide other cross-sectional shapes for EMI shielding.

[0021] According to one aspect of the invention, the first open end 15 and the second open end 40 of the EMI housing 10 are respectively closed or sealed by a first end cap 18 and a second end cap 20 to form an EMI-shielded enclosure 42 (EMI enclosure 42). Alternatively, the EMI enclosure 42 may have only one open end, which is sealed by an associated end cap, such as the first open end 15 being sealed by the first end cap 18. Figure 1For ease of illustration, walls 22, 24, 26, and 28 of the EMI enclosure 42 are shown as transparent. Various PET system components 42 (such as PET detectors with silicon photomultiplier tubes (SiPMs), lutetium oxysilicate (LSO)-based scintillation crystals, and associated detector electronics (DEA)) are housed within the cavity 30 of the EMI enclosure 42. End caps 18 and 20 may be solid (i.e., without through-holes) or may include one or more non-conductive feedthroughs and associated waveguides for attenuating radio frequency (RF) energy. See also Figure 1 The first end cap 18 is depicted as having a plurality of non-conductive through-holes 46 and associated waveguides 48, while the second end cap 20 is shown as solid. Figure 3 yes Figure 1 An enlarged view of the first end 14 of the EMI housing 10 shown. Each non-conductive through-hole 46 extends through and through an associated waveguide 48 formed in the first end cap 18. For example, each non-conductive through-hole 46 may include a non-conductive element used in conjunction with a PET system assembly 44, such as a water pipe for supplying cooling water, an optical fiber for enabling optical fiber communication, or other non-conductive elements.

[0022] In the following description, three embodiments of the first 18-end cap and the second 20-end cap will be described. Each embodiment is applicable to solid end caps or end caps with non-conductive through-holes. For clarity, the non-conductive through-holes and PET system components are not shown. See also Figure 4 Partial cross-sectional views of the first 50 end cap and the second 52 end cap of the first embodiment are shown in the exploded view (left) and the assembled view (right). The first 50 end cap and the second 52 end cap include a first 54 outer flange and a second 56 outer flange respectively abutting against a first 58 end surface and a second 60 end surface of the EMI housing 10. In addition, as will be described, a first 62 carrier element and a second 64 carrier element element are respectively attached to the first 50 end cap and the second 52 end cap.

[0023] The following description of the first embodiment uses the first end cap 50 as an example, but it should be understood that the description of the first end cap 50 also applies to the second end cap 52. Figure 5 It is along Figure 4 View of the first end cap along section line 5-5. See also Figure 4 and Figure 5The first end cap 50 includes a first stepped portion 66 and a second stepped portion 68. The first outer flange 54, as well as the first 66 and second 68 stepped portions, all have a generally rectangular shape, or alternatively, other cross-sectional shapes such as semicircles may be used. The first stepped portion 66 is designed to be smaller than the first outer flange 54, and its dimensions are designed to match the adjacent inner surfaces 32 of the upper wall 22, lower wall 24, left side wall 26, and right side wall 28 of the EMI housing 10 (see [link to relevant documentation]). Figure 2 The second step portion 68 is designed to be smaller than the first step portion 66 and includes an end cap contact surface 70. The second step portion 68 includes a conductive EMI shielding pad 72 having a generally circular cross-sectional shape (see [link to relevant documentation]). Figure 4 Alternatively, a square or other cross-sectional shape may be used. The EMI gasket 72 extends along the perimeter of the second stepped portion 68, forming a generally rectangular shape (see [link to EMI gasket]). Figure 5 (See also:) Figure 4 A conductive printed circuit board 74 (PCB 74) with an exposed metal surface is located between the first carrier 62, the end cap contact surface 70, and the EMI gasket 72. An end cap fastener 76 passes through the first end cap 50, the conductive EMI shielding gasket 78, and the PCB 74, and is screwed into a threaded insert 80 mounted in the first carrier 62, thereby removably attaching the first end cap 50 to the first carrier 62. The EMI gasket 78 is made of a conductive material and makes electrical contact with the threads 82 of the PCB 74 and the end cap fastener 76. In one embodiment, the EMI gasket 78 is made of an elastic material formed around the threads 82, thereby making electrical contact with the end cap fastener 76 to provide EMI shielding. According to one aspect of the invention, the EMI gasket 78 is made of a conductive felt material. It should be understood that more than one end cap fastener 76 and associated EMI gasket 78 and insert can be used to removably attach the first end cap 50 to the first carrier 62.

[0024] The dimensions of the second stepped portion 68 and the EMI gasket 72 are designed such that, when the assembled first end cap 50 and first carrier 62 are inserted into the first open end 15, the EMI gasket 72 is pressed tightly between the PCB 74, the first 66 and second 68 stepped portions, and the first edge segment 34 of the EMI housing 10. According to one aspect of the invention, the EMI gasket 78, PCB 74, and EMI gasket 72 are in electrical contact with the first edge segment 34 to provide EMI shielding. Similarly, the EMI gasket 78, PCB 74, and EMI gasket 72 of the second end cap 52 are in electrical contact with the second edge segment 38 to provide EMI shielding when the assembled second end cap 52 and second carrier 64 are inserted into the second open end 40.

[0025] A crossbar 84 extends from the first carrier 62 and passes through the cavity 30 of the EMI housing 10 to reach the second carrier 64. The crossbar 84 can be detachably attached to the first and second carriers 62 and 64, for example, by means of corresponding crossbar fasteners 86, thereby forming a mechanical connection between the first end cap 50 and the second end cap 52. To assemble the crossbar 84 into the EMI housing 10, the crossbar 84 is first attached to the first and second carriers 62 and 64 by means of corresponding crossbar fasteners 86. Then, an end cap (e.g., the first end cap 50) is attached to the first carrier 62 by means of end cap fasteners 76. The crossbar 84 is inserted into the first open end 15 until the first outer flange 54 contacts the first end surface 58. Then, the second end cap 52 is attached to the second carrier 64 and tightened by means of the end cap fasteners 76. This tensions the crossbar 84 between the first and second end caps, causing the first 54 and second 56 outer flanges of the first 50 and second 52 end caps to abut against the first 58 and second 60 end surfaces of the EMI housing 10, respectively, and remain fixed relative to the EMI housing 10. In this configuration, the crossbar 84 serves as a cooling structure. In one embodiment, the end caps 50, 52 and the carriers 62, 64 may be made of a polymer material.

[0026] See Figure 6 Partial sectional views of the first end cap 88 and the second end cap 90 of the second embodiment are shown in exploded view (left) and assembled view (right). The following description of the second embodiment uses the first end cap 88 as an example, but it should be understood that the description of the first end cap 88 also applies to the second end cap 90.

[0027] The first end cap 88 includes a first stepped portion 66, an end cap contact surface 70, and a conical surface 92 (replacing) Figure 4The second stepped portion 68 is shown in the diagram. A conductive planar EMI shielding pad 94 is located between the end cap contact surface 70 and a conductive flexible element (such as a rigid-flex PCB 96 with an exposed metal surface). The rigid-flex PCB 96 includes a flat base portion 98 smaller than the EMI pad 94 and a conductive contact element 100 extending from the base portion 98. The contact element 100 faces the EMI pad 94 and is flexible. An end cap fastener 76 passes through the first end cap 88, the EMI pad 94, and the rigid-flex PCB 96, and is screwed into an insert 80, thereby removably attaching the first end cap 88 to the first carrier 62. After the end cap fastener 76 is fastened to the first carrier 62, the contact surface 70, the EMI pad 94, the rigid-flex PCB 96, and the first carrier 62 are in contact with each other. The EMI pad 94 is in electrical contact with the threads 82 of the rigid-flex PCB 96 and the end cap fastener 76. In one embodiment, the EMI gasket 94 is made of an elastic material formed around the thread 82, thereby making electrical contact with the end cap fastener 76 to provide EMI shielding. According to one aspect of the invention, the EMI gasket 94 is made of a conductive felt material. It should be understood that the first end cap 88 can be detachably attached to the first carrier 62 using more than one end cap fastener 76.

[0028] After the assembled first end cap 88 and first carrier 62 are inserted into the first open end 15, the contact element 100 moves toward and contacts the first end surface 58. This causes the contact element 100 to fold toward the EMI gasket 94. The contact element 100 then contacts the EMI gasket 94, causing both the contact element 100 and the EMI gasket 94 to fold toward the tapered surface 92. The contact element 100 and the EMI gasket 94 then contact the tapered surface 92 such that they conform to the shape of the tapered surface 92, and the contact element 100 is positioned between the EMI gasket 94 and the first edge segment 34. Insertion of the first end cap 88 stops when the first outer flange 54 abuts against the first end surface 58. When this occurs, the contact element 100 is oriented at an angle corresponding to the tapered surface 92, such that the contact element 100 contacts the first edge segment 34. Therefore, the EMI gasket 94, the rigid-flex PCB 96, and the contact element 100 are electrically contacted with the first edge segment 34, thereby providing EMI shielding. Additionally, the elastic properties of the EMI gasket 94 help to push or bias the contact element 100 toward or toward the first edge segment 34 to maintain contact between the contact element 100 and the first edge segment 34. Similarly, when the assembled second end cap 90 and the second carrier 64 are inserted into the second opening end 40, the EMI gasket 94, the rigid-flex PCB 96, and the contact element 100 of the second end cap 90 are electrically contacted with the second edge segment 38, thereby providing EMI shielding.

[0029] The second embodiment of the first 88 and second 90 end caps also includes a crossbar 84. Similar to the first embodiment, the crossbar 84 is first attached to the first 62 and second 64 carriers via corresponding crossbar fasteners 86. Then, the end cap (e.g., the first end cap 88) is attached to the first carrier 62 via end cap fasteners 76. The crossbar 84 is inserted into the first open end 15 until the first outer flange 54 contacts the first end surface 58. Then, the second end cap 90 is attached to the second carrier 64 via end cap fasteners 76 and tightened. Thus, the crossbar 84 creates tension between the first 88 and second 90 end caps, causing the first 54 and second 56 outer flanges of the first 88 and second 90 end caps to abut against the first 58 and second 60 end surfaces of the EMI housing 10, respectively, and remain in place relative to the EMI housing 10. In this configuration, the crossbar 84 functions as a cooling structure.

[0030] See Figure 7 The figure shows partial sectional views of the third embodiment of the first end cap 102 and the second end cap 104, respectively, as an exploded view (left) and an assembly view (right). The following description of the third embodiment refers to the first end cap 102, but it should be understood that the description of the first end cap 102 also applies to the second end cap 104.

[0031] The first end cap 102 includes a first stepped portion 66, an end cap contact surface 70, and a tapered surface 92. In a third embodiment, a foil element 106 made of conductive material replaces the rigid-flex PCB 96. In one embodiment, the foil element 106 is made of copper. The foil element 106 includes a flat base portion 108 smaller than the EMI pad 94 and a conductive sliding contact element 110 extending from the base portion 108. The sliding contact 110 faces the EMI pad 94 and is flexible. An end cap fastener 76 passes through the first end cap 102, the EMI pad 94, and the foil element 106, and screws into an insert 80, thereby removably attaching the first end cap 102 to the first carrier 62. After the end cap fastener 76 is attached to the first carrier 62, the contact surface 70, the EMI pad 94, the foil element 106, and the first carrier 62 are in contact with each other. The EMI pad 94 is in electrical contact with the threads 82 of the foil element 106 and the end cap fastener 76. As previously described, the EMI gasket 94 is conductive and made of an elastic material (e.g., felt) that forms an electrical contact around the thread 82, thereby making electrical contact with the end cap fastener 76 and providing EMI shielding. It should be understood that multiple end cap fasteners 76 can be used to detachably attach the first end cap 102 to the first carrier 62.

[0032] After the assembled first end cap 102 and first carrier 62 are inserted into the first open end 15, the sliding contact 110 moves toward and contacts the first end surface 58. This causes the sliding contact 110 to fold toward the EMI gasket 94. The sliding contact 110 then contacts the EMI gasket 94, causing both the sliding contact 110 and the EMI gasket 94 to fold toward the tapered surface 92. The contact element 100 and the EMI gasket 94 then contact the tapered surface 92, such that the sliding contact 110 and the EMI gasket 94 conform to the shape of the tapered surface 92, and the sliding contact 110 is located between the EMI gasket 94 and the first edge segment 34. Insertion of the first end cap 102 stops when the first outer flange 54 abuts against the first end surface 58. At this time, the sliding contact 110 is at an angle relative to the tapered surface 92, such that the sliding contact 110 contacts the first edge segment 34. Therefore, the EMI gasket 94, foil element 106, and sliding contact 110 are electrically contacted with the first edge segment 34, thereby providing EMI shielding. Furthermore, the elastic properties of the EMI gasket 94 help to push or bias the sliding contact 110 towards or off the first edge segment 34 to maintain electrical contact between the sliding contact 110 and the first edge segment 34. Similarly, when the assembled second end cap 104 and second carrier 64 are inserted into the second opening end 40, the EMI gasket 94, foil element 106, and sliding contact 110 of the second end cap 104 are electrically contacted with the second edge segment 38, thereby providing EMI shielding.

[0033] The third embodiment of the first 102 and second 104 end caps also includes a crossbar 84. Similar to the first embodiment, the crossbar 84 is first attached to the first 62 and second 64 carriers via respective crossbar fasteners 86. Then, the end cap (e.g., the first end cap 102) is attached to the first carrier 62 via end cap fasteners 76. The crossbar 84 is inserted into the first open end 15 until the first outer flange 54 contacts the first end surface 58. Then, the second end cap 104 is attached to the second carrier 64 via end cap fasteners 76 and tightened. This tensions the crossbar 84 between the first 102 and second 104 end caps so that the first 54 and second 56 outer flanges of the first 102 and second 104 end caps abut against the first 58 and second 60 end surfaces of the EMI housing 10, respectively, and remain in place relative to the EMI housing 10. In this configuration, the crossbar 84 functions as a cooling structure.

[0034] See Figure 8The image shows a partial cross-sectional top view of the EMI housing 10 and the first end cap 102 according to a third embodiment. The EMI housing 10 includes: a hollow circular tube 112 having a tapered mounting portion 114; and a power cable 116 including a cable braid layer 118. The tube 112 functions as a waveguide 112 when its length is at least three times its effective diameter and no conductor or metal structure passes through or resides within it. Figure 9 yes Figure 8 The diagram shows a perspective view of the power cable 116. At least one conductor 120 extends through the cable braid 118 of the power cable 116. A grounding flange 122 is formed on the cable braid 118, extending laterally relative to the longitudinal axis 12.

[0035] Figure 9 This is an exploded view of an exemplary first end of the EMI housing 10. See also Figure 7 , Figure 8 and Figure 9 The tapered portion 114 of waveguide 112 and the grounding flange 122 of cable braid 118 are located between the EMI gasket 94 and foil element 106 of the third embodiment of the first end cap 102. When the first end cap 102 is assembled onto the first carrier 62, the tapered portion 114 and the grounding flange 122 are pressed tightly between the EMI gasket 94 and the foil element 106 and form an electrical contact, thereby grounding the waveguide 112 and the power cable 116. Alternatively, a second embodiment of the first end cap 88 can be used to ground the waveguide 112 and the power cable 116 by pressing the tapered portion 114 and the grounding flange 122 between the EMI gasket 94 and the rigid-flex PCB 96.

[0036] This invention applies to any EMI shielding enclosure, such as those used in MR / PET systems. See also Figure 11 The image shows a front view of an MR / PET imaging system 124, depicting at least one EMI shielding enclosure 42 of the present invention. The system 124 includes a patient channel 126 or tunnel for accommodating a patient to be scanned, a body coil 128 (MRI system component), a PET gantry 130 (PET system component) including at least one EMI shielding enclosure 42 arranged longitudinally along a longitudinal axis 12, a gradient coil 132 (MRI system component), and a superconducting magnet 134 (MRI system component).

[0037] While specific embodiments of this disclosure have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of this disclosure. Therefore, it is intended to cover all such changes and modifications within the scope of this disclosure.

Claims

1. A housing for shielding electromagnetic interference (EMI), the housing comprising: An EMI shielding housing having a plurality of walls and at least one open end, wherein the walls define an internal cavity, and wherein the inner surface of at least one wall includes a conductive edge segment located at the open end; An end cap, which is detachably attached to the opening end; A conductive foil element having a sliding contact; A flexible EMI pad, which is conductive and located between the end cap and the foil element, wherein the foil element forms an electrical contact with the EMI pad, and wherein the sliding contact and the EMI pad are folded such that the sliding contact is located between the EMI pad and the edge segment, wherein the sliding contact forms an electrical contact with the edge segment to provide EMI shielding, and the EMI pad is biased to push the sliding contact toward the edge segment to maintain electrical contact.

2. The enclosure of claim 1, further comprising a carrier element, wherein a fastener extends through the end cap, the EMI gasket, the foil element, and the carrier element to removably attach the end cap to the carrier element, wherein the EMI gasket is formed around the fastener to make electrical contact with the fastener to provide EMI shielding.

3. The enclosure according to claim 1, wherein the EMI housing is made of carbon fiber, and the conductivity of the edge segment is enhanced by attaching a metal strip to the edge segment, coating the edge segment with metallic paint, or polishing the edge segment to expose the carbon fiber of the EMI housing.

4. The enclosure according to claim 1, further comprising at least one waveguide having a tapered mounting portion, wherein the mounting portion is located between the EMI gasket and the foil element.

5. The enclosure according to claim 4, wherein the length of the waveguide is at least three times the effective diameter of the waveguide.

6. The enclosure according to claim 1, wherein a power cable having a cable braided layer passes through the end cap, wherein a grounding flange is formed on the cable braided layer and located between the EMI gasket and the foil element.

7. A housing for shielding electromagnetic interference (EMI) in a magnetic resonance / positron emission tomography (MR / PET) imaging system, the housing comprising: An EMI shielding housing having a plurality of walls terminating at a first end surface and a second end surface to define a first opening end and a second opening end, wherein the walls also define an internal cavity, and wherein the inner surface of at least one wall includes a conductive first edge segment and a second edge segment located at the first opening end and the second opening end, respectively. A first end cap and a second end cap, the first end cap and the second end cap respectively having a first outer flange and a second outer flange, the first end cap and the second end cap including a first conductive foil element and a second conductive foil element having a first sliding contact and a second sliding contact, and conductive first and second elastic EMI gaskets respectively located between the first end cap and the first foil element and the second foil element, wherein the first foil element and the second foil element are in electrical contact with the first EMI gasket and the second EMI gasket respectively, and wherein the first sliding contact and the second sliding contact, as well as the first EMI gasket and the second EMI gasket, are folded such that the first sliding contact and the second sliding contact are respectively located between the first EMI gasket and the second EMI gasket and the first edge segment and the second edge segment, wherein the first sliding contact and the second sliding contact are in electrical contact with the first edge segment and the second edge segment respectively to provide EMI shielding, and wherein the first EMI gasket and the second EMI gasket are biased to push the first sliding contact and the second sliding contact toward the first edge segment and the second edge segment respectively to maintain electrical contact; and A crossbar extending through the EMI housing, wherein the crossbar is removably attached between the first end cap and the second end cap by corresponding fasteners, wherein tightening at least one fastener tensions the crossbar (84) between the first (102) end cap and the second (104) end cap, such that the first outer flange and the second outer flange abut against the surfaces of the first end cap and the second end cap, respectively, thereby holding the first end cap and the second end cap to the EMI housing.

8. The enclosure of claim 7, further comprising a first carrier element and a second carrier element respectively detachably attached to the first end cap and the second end cap, wherein the first fastener and the second fastener extend through the first end cap and the second end cap, the first EMI gasket and the second EMI gasket, the first foil element and the second foil element, and the first carrier element and the second carrier element to detachably attach the first end cap and the second end cap to the first carrier element and the second carrier element respectively, wherein the first EMI gasket and the second EMI gasket are formed around the first carrier element and the second fastener to make electrical contact with the first fastener and the second fastener respectively to provide EMI shielding.

9. The enclosure of claim 7, wherein the EMI housing is made of carbon fiber, and the conductivity of the first edge segment and the second edge segment is enhanced by attaching metal strips to the edge segment, coating the edge segment with metallic paint, or polishing the first edge segment and the second edge segment to expose the carbon fiber of the EMI housing.

10. The enclosure of claim 7, further comprising at least one waveguide having a tapered mounting portion, wherein the mounting portion is located between the first EMI gasket and the first foil element of the first end cap.

11. The enclosure according to claim 10, wherein the length of the waveguide is at least three times the effective diameter of the waveguide.

12. The enclosure of claim 7, wherein a power cable having a cable braided layer passes through the first end cap, wherein a grounding flange formed on the cable braided layer is located between the first EMI gasket and the first foil element.

13. The enclosure of claim 7, wherein the enclosure comprises a PET system component.

14. A method for shielding an enclosure from electromagnetic interference (EMI), the method comprising: An EMI shielding housing is provided having multiple walls and at least one open end, wherein the walls define an internal cavity and the open end includes an end surface; A conductive edge segment is provided at the opening end and on the inner surface of at least one wall; An end cap is provided that is detachably attached to the open end, wherein the end cap includes a flange; Provide conductive foil elements with sliding contacts; A conductive, resilient EMI gasket is provided between the end cap and the foil element, wherein the foil element forms an electrical contact with the EMI gasket; as well as The end cap is inserted into the open end, wherein the contact between the sliding contact and the end surface causes the sliding contact and the EMI pad to fold, such that the sliding contact is positioned between the EMI pad and the edge segment, wherein the sliding contact and the edge segment form an electrical contact to provide EMI shielding, and the EMI pad is biased to push the sliding contact toward the edge segment to maintain the electrical contact.

15. The method of claim 14, further comprising providing a carrier element, wherein fasteners extend through the end cap, the EMI gasket, the foil element, and the carrier element to removably attach the end cap to the carrier element.

16. The method of claim 15, further comprising forming the EMI gasket around the fastener to make electrical contact with the fastener to provide EMI shielding.

17. The method of claim 14, wherein the EMI housing is made of carbon fiber and further comprises: Attach the metal strip to the edge segment; The edge segment may be coated with metallic paint; or the edge segment may be sanded to expose the carbon fiber of the EMI housing to enhance the conductivity of the edge segment.

18. The method of claim 14, further comprising: At least one waveguide is provided having a tapered mounting portion, wherein the mounting portion is located between the EMI pad and the foil element.

19. The method of claim 18, wherein the length of the waveguide is at least three times the effective diameter of the waveguide.

20. The method of claim 14, further comprising: A power cable is provided having a cable braided layer extending through the end cap, wherein a grounding flange is formed on the cable braided layer and located between the EMI gasket and the foil element.

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