| 摘要 |
A tracking device configured to be coupled to an interventional instrument and tracked by a magnetic resonance imaging system is provided. The tracking device includes, for example, paramagnetic and diamagnetic components that form first and second tracking members. When the tracking device is adjusted into a first arrangement, the tracking device will produce a local magnetic field in the presence of the magnetic field of an MRI system that is measurable by the MRI system. However, when the tracking device is adjusted into a second arrangement, the local magnetic field produced by the tracking device is reduced relative to the first arrangement, wherein the reduced local magnetic field produces substantially no magnetic field disturbances detectable by the MRI system. Images may be acquired of a patient in which the tracking device has been introduced and, using a numerical fitting method, an accurate location of the tracking device can be determined. |
