Abstract:
A lead for an electronic device which resists the induction of a current from an electromagnetic field external to said lead includes one or more pairs of adjacent segments of electrical wire, each of the pairs including a first segment of electrical wire and a second segment of electrical wire. The lead also includes one or more shielded RF chokes, wherein each of the shielded RF chokes is provided between the first segment of electrical wire and the second segment of electrical wire of a respective one of the one or more pairs of adjacent segments. Also, an implantable device that includes a generator for generating one or more electrical pulse and a lead as described for delivering the pulses to tissue within a patient's body. A method for making the described implantable device is also provided.
Abstract:
Featured are devices, systems and methods for localized heating of a vessel as well as devices, systems and methods for MR/NMR imaging of a vessel while locally heating a portion of the vessel. More particularly featured are such devices, systems and methods for use when administering or delivering therapeutic agents including genes and/or drugs to the tissues of the vessel. Such a method includes positioning a thermal energy delivery device proximal a target site with the vessel of a body and activating the thermal energy delivery device so as to heat the target site thereby locally increasing a temperature of tissue at the target site. In further embodiments, the method includes introducing a therapeutic medium to the target site over a predetermined time period, and wherein said activating occurs at least one of before, during or after said step of introducing.
Abstract:
A system and method for using magnetic resonance imaging to increase the accuracy of electrophysiologic procedures is disclosed. The system in its preferred embodiment provides an invasive combined electrophysiology and imaging antenna catheter which includes an RF antenna for receiving magnetic resonance signals and diagnostic electrodes for receiving electrical potentials. The combined electrophysiology and imaging antenna catheter is used in combination with a magnetic resonance imaging scanner to guide and provide visualization during electrophysiologic diagnostic or therapeutic procedures. The invention is particularly applicable to catheter ablation, e.g., ablation of atrial fibrillation. In embodiments which are useful for catheter ablation, the combined electrophysiology and imaging antenna catheter may further include an ablation tip, and such embodiment may be used as an intracardiac device to both deliver energy to selected areas of tissue and visualize the resulting ablation lesions, thereby greatly simplifying production of continuous linear lesions. The invention further includes embodiments useful for guiding electrophysiologic diagnostic and therapeutic procedures other than ablation. Imaging of ablation lesions may be further enhanced by use of MR contrast agents. The antenna utilized in the combined electrophysiology and imaging catheter for receiving MR signals is preferably of the coaxial or “loopless” type. High-resolution images from the antenna may be combined with low-resolution images from surface coils of the MR scanner to produce a composite image. The invention further provides a system for eliminating the pickup of RF energy in which intracardiac wires are detuned by filtering so that they become very inefficient antennas. An RF filtering system is provided for suppressing the MR imaging signal while not attenuating the RF ablative current. Steering means may be provided for steering the invasive catheter under MR guidance. Other ablative methods can be used such as laser, ultrasound, and low temperatures.
Abstract:
An MR system and method for tracking a device of an interventional procedure within a scan subject is disclosed. At least two MR projections of the device are acquired, from which 3D coordinates of the device are determined. Subsequent image acquisition is adjusted with respect to the coordinates of the device to guide movement thereof towards target anatomy. The present system and method provide the ability to locate and visualize continuous portions of an interventional device in 3D, and do not require the use of embedded RF localizing coils.
Abstract:
Disclosed is a method and system for steady state free precession based magnetic resonance thermometry that measures changes in temperature on a pixel by pixel basis. The method comprises generating an RF pulse sequence used to find the proton resonance frequency shift, which is proportional to temperature change, processing the resultant MRI data to measure the proton frequency shift, and converting the measured proton frequency shift into change in temperature data. Further disclosed is a method for identifying and compensating for temperature drifts due to core heating of the gradient magnet.
Abstract:
The invention describes a system, method, and means for an MRI guidewire that can be visible on an MRI, can act as an antenna and receive MRI signals from surrounding subject matter, and can allow the use of multiple interventional tools without removal of the guidewire from a subject.
Abstract:
The apparatus, systems and methods of the present invention provide for MRI sleeves, probes, and combinations thereof adapted for insertion into a subject, in order to internally image regions of the subject.
Abstract:
A system for multi-slice magnetic resonance imaging (MM) comprises a gradient coil array comprising a plurality of independent coils distributed about an enclosure; and a controller configured to concurrently actuate said plurality of coils so as to generate a spatially-varying magnetic field within said enclosure such that for at least first and second volumetric slices, a magnetic field magnitude associated with at least one location in the first volumetric slice is substantially equal to a magnetic field magnitude associated with a respective location in the second volumetric slice.
Abstract:
A radio-frequency (RF) coil for obtaining magnetic resonance data for imaging the cervical region of a patient has a loop coil contained in a housing of an applicator assembly that is adapted for placement against the cervix of the patient, and a loopless antenna contained in a tandem applicator of the assembly, that is adapted for intracorporeal placement in the cervix of the patient.
Abstract:
A lead for an electronic device which resists the induction of a current from an electromagnetic field external to said lead includes one or more pairs of adjacent segments of electrical wire, each of the pairs including a first segment of electrical wire and a second segment of electrical wire. The lead also includes one or more shielded RF chokes, wherein each of the shielded RF chokes is provided between the first segment of electrical wire and the second segment of electrical wire of a respective one of the one or more pairs of adjacent segments. Also, an implantable device that includes a generator for generating one or more electrical pulse and a lead as described for delivering the pulses to tissue within a patient's body. A method for making the described implantable device is also provided.