Mri-compatible devices

Abstract

The present disclosure provides medical devices having MRI-compatible circuitry. Preferably, the devices do not project an enlarged profile, yet their position can be determined during an iMRI procedure. Illustrative embodiments of such a device can include a base surface, a first conducting layer disposed on the base surface, a first insulating layer disposed over at least a portion of the first conducting layer, and a second conducting layer disposed over at least a portion of the first insulating layer.

What is claimed is: 
     
         1 . An interventional magnetic resonance imaging (iMRI) device having MRI-compatible circuitry, comprising:
 a base surface;   a first semi-active magnetic resonance marker formed from a first conducting layer disposed on the base surface to form a resonant circuit, the resonant circuit having a resonant frequency tuned to match the local Larmour frequency corresponding to the background magnetic field B 0  of a MRI scanner, wherein the resonant circuit is operable to emit a radio frequency signal responsive to being stimulated by a radio frequency at the resonant frequency.   
     
     
         2 . The medical device of  claim 1 , further comprising a first insulating layer disposed over at least a portion of the first conducting layer. 
     
     
         3 . The medical device of  claim 1 , wherein the resonant circuit is a self-resonant LC tank circuit that is tuned to the local Larmour frequency. 
     
     
         4 . The medical device of  claim 1 , wherein the resonant circuit is printed using a conductive ink. 
     
     
         5 . The medical device of  claim 1 , further comprising a second semi-active magnetic resonance marker, wherein the first semi-active magnetic resonance marker and the second semi-active magnetic resonance marker are spatially configured to permit a user to determine the directional orientation of the medical device while being visualized under active MRI. 
     
     
         6 . The medical device of  claim 1 , wherein the medical device includes an elongate shaft and further wherein the first and second semi-active magnetic resonance markers are disposed on the elongate shaft with a relative rotational offset about a central axis of the elongate shaft. 
     
     
         7 . The medical device of  claim 1 , wherein the resonant frequency corresponds to the Larmour frequency of a B 0  of 0.55 Tesla. 
     
     
         8 . The medical device of  claim 1 , wherein the resonant frequency corresponds to the Larmour frequency of a B 0  of 1.5 Tesla. 
     
     
         9 . The medical device of  claim 1 , wherein the resonant frequency corresponds to the Larmour frequency of a B 0  of 3.0 Tesla. 
     
     
         10 . A method of performing a real time MRI diagnostic procedure, comprising introducing the medical device of  claim 1  into a sample or subject disposed within a bore of a magnetic resonance imaging scanner and visualizing the location of the resonant circuit in real time. 
     
     
         11 . The method of  claim 10 , wherein amplified magnetic field over the resonant circuit couples with at least one imaging coil of the magnetic resonance imaging scanner wirelessly to visualize the interventional MRI device. 
     
     
         12 . The medical device of  claim 2 , wherein the first insulating layer is printed onto the medical device. 
     
     
         13 . The medical device of  claim 1 , wherein the first conductive layer is formed using a technique other than printing. 
     
     
         14 . The medical device of  claim 13 , wherein the first conductive layer is formed using a chemical vapor deposition technique. 
     
     
         15 . The medical device of  claim 2 , wherein the first insulating layer is formed from a sleeve of insulating material.