# US 2025/0164591 A1 · Shim elements for use with a magnetic resonance apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0164591 A1 - Document ID: US20250164591A1 - Status: Published application - Kind: A1 - Application number: 18/842,423 - Filed: 2023-02-20 - Published: 2025-05-22 - Earliest claimed: 2022-03-01 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Peter Forthmann; Gerardus Bernardus Jozef Mulder - Web page: https://patentgrep.com/patent/US20250164591A1 ## CPC - G01R 33/3873: using ferromagnetic bodies {; Passive shimming} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract The invention relates to shim elements (100, . . . , 115) for magnetic resonance applications. According to the invention, the shim elements (100, . . . , 115) comprise shim blocks (101, . . . , 115) which are each separate from each other such that each shim block (101, . . . , 115) may be individually inserted into a shim opening (9) of a magnetic field-generating unit (2) of the magnetic resonance apparatus (1), wherein each shim block (101, . . . , 115) comprises a relative amount of shim iron (10), and the set comprises at least two shim blocks (101, . . . , 115) for which the respective amount of the shim iron (10) is different from each other. In this way, the shimming procedure may be simplified and the shim capacity may be increased to a high pultrusion volume. ## Claims ### Claim 1 A set of shim elements comprising: shim blocks which are each separate from each other such that each shim block may be individually inserted into a shim opening of a magnetic field-generating unit of a magnetic resonance apparatus, each shim block comprises a relative amount of shim iron relative to the block's total amount of iron and non iron-material, and the set comprises at least two shim blocks for which the respective relative amount of shim iron is different from each other. ### Claim 2 (depends on 1) The set of shim elements according to claim 1, wherein the relative amount of shim iron in each shim block is provided by a number of shim iron plates which all have the same weight and/or dimensions. ### Claim 3 (depends on 1) The set of shim elements according to claim 1, wherein the shim elements all have the same outer shape, and wherein the volume of each shim element which is not filled with shim iron is made from a magnetically passive material. ### Claim 4 (depends on 3) The set of shim elements according to claim 3, wherein the outer shape is such that two respective shim elements may be connected to each other by form fit. ### Claim 5 (depends on 1) The set of shim elements according to claim 1, wherein the shim elements are each provided with interlockings such that respective two shim elements may be interlocked to each other via these interlockings. ### Claim 6 (depends on 1) The set of shim elements according to claim 1, wherein the shim iron is arranged inside each shim block such that a part of the shim iron forms an outer surface of the shim block or lies directly next to an outer surface of the shim block. ### Claim 7 (depends on 1) The set of shim elements according to claim 1, wherein the shim elements comprise at least one dummy block which is separate from all shim blocks of the set such that also the dummy block may be individually inserted into a shim opening of a magnetic field-generating unit of the magnetic resonance apparatus, wherein the dummy block is free of any shim iron. ### Claim 8 (depends on 1) The set of shim elements according to claim 1, wherein each shim elements comprises an indication on its outside which indicates the relative amount of shim iron comprised by the respective shim element. ### Claim 9 (depends on 1) A magnetic resonance apparatus with a bore for accommodating a subject under examination and a magnetic field-generating unit surrounding the bore, wherein the field-generating unit comprises a plurality of shim openings which run parallel to the longitudinal axis of the bore and wherein at least one of the plurality of shim openings comprises a set of shim elements according to claim 1. ### Claim 10 (depends on 8) The MR apparatus according to claim 8, wherein all shim openings are completely filled with a respective set of shim elements. ### Claim 11 (depends on 9) The MR apparatus according to claim 9, wherein the shim elements have a cross section which corresponds to the cross section of the shim openings. ### Claim 12 (depends on 9) The MR apparatus according to claim 9, wherein the shim elements are connected to each other by a detachable string and/or wherein the shim elements are wrapped into a sleeve. ### Claim 13 (depends on 1) A method of shimming a magnetic resonance apparatus which comprises a magnetic field-generating unit with multiple shim openings, comprising: providing a set of shim elements according to claim 1, lining up the shim elements according to an order which has been determined beforehand under shimming requirement for the magnetic imaging apparatus, and inserting the lined-up shim elements in their beforehand-determined order into a respective shim opening one after the other. ### Claim 14 (depends on 13) The method according to claim 13, wherein the shim elements are connected to each other by a string before insertion into the shim opening. ### Claim 15 (depends on 13) The method according to claim 13, wherein the shim elements are wrapped into a sleeve before insertion into the shim opening.