Mri compatible vascular occlusive devices and related methods of treatment and methods of monitoring implanted devices

Abstract

Implantable aneurysm-sac treatment devices include an implantable coil body configured and sized to reside in a sac of an aneurysm. The body has an inductance and capacitance. The capacitance is selected so that the coil resonates at a Larmor frequency of a predefined magnetic field strength.

1 - 16 . (canceled) 
     
     
         17 . An MRI system for evaluating an aneurysm in vivo, comprising: at least one implantable RF resonator configured and sized to reside in an intracranial aneurysm sac in a patient, wherein the at least one RF resonator has a resonant frequency corresponding to an operating frequency associated with magnetic field strength of an MRI scanner system; a body coil in communication with an RF excitation source associated with the MRI scanner system, the body coil disposed on the patient the body coil being configured to inductively couple with the at least one RF resonator to transmit RF excitation pulses comprising low flip angle pulses, from the RF excitation source inside of and proximate the at least one RF resonator; and a surface coil in communication with the MRI scanner system and the at least one RF resonator, wherein, in operation, the at least one RF resonator picks up local MR signal data and cooperates with the surface coil to amplify local signal data from the RF resonator. 
     
     
         18 . An embolic vascular occlusion device, comprising: a microcoil configured and sized for implantation in an aneurysm sac; and at least one MEMS pressure sensor held by the microcoil. 
     
     
         19 . A method of obtaining image data to guide filling an aneurysm sac with embolic material, comprising: obtaining MRI signal data from an internal implantable RF resonator disposed proximate an aneurysm sac; and filling the sac with a selected embolic material using the obtained MRI signal data. 
     
     
         20 . A method according to  claim 19 , wherein the obtaining step is carried out in substantially real time during the filling step so that the sac can be filled to a desired level without unduly over or under filling the sac space. 
     
     
         21 . A method of obtaining image data to guide filling an aneurysm sac with embolic material, comprising: obtaining MRI signal data from an intra-body RF antenna disposed proximate an aneurysm sac; and filling the sac with a selected embolic material using the obtained MRI signal data. 
     
     
         22 . A method according to  claim 21 , further comprising implanting an RF resonator in the aneurysm sac. 
     
     
         23 . A method according to  claim 22 , wherein the obtaining step is carried out using the RF antenna and the RF resonator during the filling step. 
     
     
         24 . A method according to  claim 21 , wherein the filling step comprises at least one of the following: introducing embolic liquid into the sac; and introducing at least one coil into the sac. 
     
     
         25 . A method according to  claim 22 , wherein the intra-body antenna is a guidewire or catheter that is spaced apart from the RF resonator, and wherein the RF resonator is non-active during implantation. 
     
     
         26 . A method of monitoring the status of an aneurysm, comprising: obtaining MRI signal data from an internal implanted RF resonator disposed in an aneurysm sac to provide images of the aneurysm sac with sufficient detail to allow a clinician to visualize in the MRI image, the presence or absence of at least one of the following: thrombosis, scarring, recanalization, anatomical or structural changes in the sac and blood flow into the sac. 
     
     
         27 . A method of using MRI signal data to guide placement of embolic material in an aneurysm sac, comprising: introducing a catheter holding a detachable RF resonator coil into a patient; and obtaining MRI signal data in substantially real-time from the internal RF resonator coil proximate an aneurysm sac in the patient. 
     
     
         28 . A method according to  claim 27 , further comprising detaching the RF resonator coil from the catheter and implanting the RF resonator coil in the aneurysm sac. 
     
     
         29 . A method according to  claim 28 , wherein the obtaining step is carried out before the detaching step. 
     
     
         30 . A method according to  claim 28 , wherein the obtaining step is carried out before and after the detaching step. 
     
     
         31 . A method according to  claim 28 , wherein the obtaining step is carried out after the detaching step. 
     
     
         32 . A method of using MRI signal data to guide placement of embolic material in an aneurysm sac, comprising: obtaining MRI signal data in substantially real-time from an RF antenna proximate an aneurysm sac in the patient; and introducing embolic material into the aneurysm sac based on images generated from the obtaining step. 
     
     
         33 . A method according to  claim 32 , wherein the introducing step comprises implanting an RF resonator coil into the aneurysm sac. 
     
     
         34 . A method according to  claim 32 , wherein the introducing step comprises introducing liquid embolic material into the aneurysm sac.