System and method for control of RF circuits for use with an MRI system
First Claim
Patent Images
1. A radio-frequency (RF) system for use with a magnetic resonance imaging (MRI) system during a imaging process of a subject, the RF system comprising:
- a radio frequency (RF) element configured to at least one of transmit RF energy to and receive RF energy from the subject during the medical imaging process;
an array of reactive components coupled to the RF element and configured to adjust at least one of an impedance transformation and a frequency tuning associated with the RF element;
a mismatch detector circuit configured to measure a reflected signal from the RF element using a coupler including a coupling port and an isolated port separated by a desired phase shift providing isolation therebetween; and
a feedback circuit configured to receive an indication of the reflected signal from the mismatch detector circuit and automatically determine at least one of an impedance adjustment and a frequency tuning to be implemented by adjusting the array of reactive components based on the reflected signal to effectuate transmit-receive isolation.
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Abstract
A system and method for automatically adjusting electrical performance of a radio frequency (RF) coil assembly of a magnetic resonance imaging (MRI) system during a medical imaging process of a subject to control changes in loading conditions of the RF coil caused by the subject during the medical imaging process.
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Citations
24 Claims
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1. A radio-frequency (RF) system for use with a magnetic resonance imaging (MRI) system during a imaging process of a subject, the RF system comprising:
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a radio frequency (RF) element configured to at least one of transmit RF energy to and receive RF energy from the subject during the medical imaging process; an array of reactive components coupled to the RF element and configured to adjust at least one of an impedance transformation and a frequency tuning associated with the RF element; a mismatch detector circuit configured to measure a reflected signal from the RF element using a coupler including a coupling port and an isolated port separated by a desired phase shift providing isolation therebetween; and a feedback circuit configured to receive an indication of the reflected signal from the mismatch detector circuit and automatically determine at least one of an impedance adjustment and a frequency tuning to be implemented by adjusting the array of reactive components based on the reflected signal to effectuate transmit-receive isolation. - View Dependent Claims (2, 3, 4, 5)
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6. A method for automatically controlling operation of a radio frequency (RF) element for use with a magnetic resonance imaging (MRI) system, the method comprising the steps of:
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(a) determining at least one of a frequency tuning need and an impedance matching mismatch; (b) determining a desired performance of the RF element including a desired isolation between transmit and receive functionality of the RF element to be achieved by reducing the at least one of a frequency tuning need and an impedance matching mismatch; (c) adjusting at least one reactive component coupled to the RF element to reduce the at least one of frequency tuning need and impedance matching mismatch based on the desired performance of the RF coil element and achieve the desired isolation between transmit and receive functionality of the RF element; and (d) repeating step (c) during an MRI process using the RF coil element to control the at least one of frequency tuning need and impedance matching mismatch and the desired isolation based on the desired performance of the RF element despite loading condition changes during the MRI process. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A system for automatically adjusting electrical performance of a radio frequency (RF) system of a magnetic resonance imaging (MRI) system during a medical imaging process of a subject, the system comprising:
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an adjustment circuit coupled between the MRI system and the RF system; a coupler providing isolation between the MRI system and the RF system; a frequency detector circuit configured to measure a resonance frequency from the RF system; a feedback circuit configured to receive an indication of the resonance frequency from the frequency detector circuit and determine at least one of a frequency tuning need and a impedance matching mismatch using the resonance frequency; and a control circuit configured to control operation of the adjustment circuit to implement at least one of frequency tuning adjustments and impedance matching adjustments to control changes in the resonance frequency at least caused by changes in loading conditions of the RF system caused by the subject during the medical imaging process. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A radio-frequency (RF) system for use with a magnetic resonance imaging (MRI) system during a imaging process of a subject, the RF system comprising:
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a radio frequency (RF) element configured to transmit RF energy to and receive RF energy from the subject during the medical imaging process; an array of reactive components coupled to the RF element to perform a parallel imaging process; a diode system configured to provide electrical isolation between components of the RF stem and adjust parameters of the reactive components to perform at least one of an impedance matching and a frequency tuning of the RF element; and a control circuit configured to control the diode system to adjust parameters of the reactive components. - View Dependent Claims (23, 24)
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Specification