SYSTEM AND METHOD FOR TRACKING MEDICAL DEVICE USING MAGNETIC RESONANCE DETECTION
First Claim
1. A system for tracking the location of a medical device within an MRI machine, comprising:
- an MRI machine;
a medical device for treating or diagnosing a patient;
a tracking device attached to said medical device, said tracking device adapted to receive an MR response signal, having a readout gradient, generated by material in a close vicinity of said tracking device when said material is excited by said MR machine;
wherein said MRI machine is adapted to apply a dephasing gradient substantially perpendicular to said readout gradient before said MR response signal is received by the tracking device.
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Accused Products
Abstract
A system and method for using magnetic resonance to track a medical device which attenuates interfering MR signals. The system comprises an MR tracking device comprising one or more radiofrequency (RF) tracking coils adapted to receive a magnetic resonance MR response signal from nuclei excited by an RF pulse. Ideally, the RF tracking coil only receives an MR response signal from nuclei in matter in the close vicinity of the tracking device. The tracking device is attached to medical device. The interfering signal tends to emanate from large objects or large volumes that are outside the close vicinity of the tracking device but which are still weakly coupled to the tracking device. A dephasing gradient is applied perpendicular to the readout gradient before the RF response signal is received thereby dephasing the interfering signal emanating from remote nuclei, which strongly attenuates the interfering signal while the MR response signal is substantially unaffected. The system can also detect errors in tracking location by checking the amplitude of the signal from each coil and the detected distance between each coil, and correcting for such errors by ignoring data from coils having low amplitude or location deviating from known location relative to the other coils.
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Citations
20 Claims
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1. A system for tracking the location of a medical device within an MRI machine, comprising:
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an MRI machine; a medical device for treating or diagnosing a patient; a tracking device attached to said medical device, said tracking device adapted to receive an MR response signal, having a readout gradient, generated by material in a close vicinity of said tracking device when said material is excited by said MR machine; wherein said MRI machine is adapted to apply a dephasing gradient substantially perpendicular to said readout gradient before said MR response signal is received by the tracking device. - View Dependent Claims (2, 3, 4, 5, 6, 8)
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9. A system for tracking the location of a medical device within an MRI machine, comprising:
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an MRI machine comprising; a magnet for applying a substantially uniform magnetic field throughout an imaging region within said MRI machine; a magnetic gradient generator for generating a magnetic field of varying amplitude in a selected number of dimensions within said imaging region; an RF transmitter for transmitting RF energy of a selected pulse sequence within said imaging region; an RF receiver for receiving a magnetic resonance response signal emitted from resonating nuclei; an image processing system operably coupled to said RF receiver, said image processing system adapted to process said magnetic resonance response signal into spatial location an image data; and a display operably coupled to said image processing system for displaying the image represented by said image data; a medical device for treating or diagnosing a patient; a tracking device attached to said medical device, said tracking device adapted to receive an MR response signal, having a readout gradient, generated by material in a close vicinity of said tracking device which is excited by said MR machine, said tracking device operably coupled to said image processing system, said image processing system adapted to process said; and wherein said MRI machine is adapted to apply a dephasing gradient substantially perpendicular to said readout gradient before said RF response signal is received by the tracking device.
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10. A method of tracking the location of a medical device within an imaging region of an MRI machine, comprising the following steps:
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a) providing a medical device within the imaging region of the MRI machine, said medical device having a tracking device attached thereto, said tracking device adapted to receive an MR response signal generated by material in a close vicinity of said tracking device when said material is excited by said MRI machine; b) transmitting an RF pulse into said imaging region and applying a magnetic field gradient to the imaging region such that material in the close vicinity of said tracking device emits an MR response signal; c) applying a dephasing gradient substantially perpendicular to said readout gradient; d) receiving said MR response signal with said tracking device; and e) determining the location of said tracking device using said received MR response signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification