RF-safe interventional or non-interventional instrument for use in an MRI apparatus
First Claim
1. An RF-safe interventional or non-interventional instrument for use in an MR imaging apparatus, the instrument comprising:
- a conductor which is subject to an RF common mode current,at least one electrically damping element disposed at approximately a position along the conductor where an RF electric field strength of the RF common mode occurs, wherein the damping element is a resistive load in the form of a wire extension which has one end electrically connected with the conductor, wherein the other end is electrically open, to attenuate or suppress the RF common mode current or the RF electric field strength on the conductor, anda temperature sensor configured to sense the temperature of the damping element.
1 Assignment
0 Petitions
Accused Products
Abstract
An RF-safe interventional or a non-interventional instrument is used during an MR imaging or MR examination of an examination object (A). The instrument is made of or includes at least one longitudinal or elongated electrically conductive element (1, 3), for example, in the form of a conductor or wire or line for feeding electrical signals, or in the form of the instrument itself or a component or a part thereof, which is not provided for feeding electrical signals but is nevertheless electrically conductive. All such elements are subject to RF common mode currents which are induced in the element when the instrument or element is exposed to an RF/MR excitation field generated during MR imaging or MR examination by an MR imaging apparatus. The instrument is made RF-safe by increasing the energy loss of an oscillator which is represented by the conductor (1, 3) by a damping element (4; 6) in order to prevent or limit RF heating of the examination object (A) at or surrounding the conductor (1, 3).
17 Citations
9 Claims
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1. An RF-safe interventional or non-interventional instrument for use in an MR imaging apparatus, the instrument comprising:
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a conductor which is subject to an RF common mode current, at least one electrically damping element disposed at approximately a position along the conductor where an RF electric field strength of the RF common mode occurs, wherein the damping element is a resistive load in the form of a wire extension which has one end electrically connected with the conductor, wherein the other end is electrically open, to attenuate or suppress the RF common mode current or the RF electric field strength on the conductor, and a temperature sensor configured to sense the temperature of the damping element.
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2. An RF-safe interventional or non-interventional instrument for use in an MR imaging apparatus, the instrument comprising:
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a conductor which is subject to an RF common mode current, at least one electrical damping element disposed at approximately a position along the conductor where an RF electric field strength of the RF common mode occurs, wherein the damping element is selected to be at least one of a resistive, a reactive or a dielectric load which attenuates or suppresses the RF common mode current or the RF electric field strength on the conductor, and a temperature sensor configured to sense the temperature of the damping element. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9)
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Specification