Certain implementations of the disclosed technology may include active marker devices, retrofits, systems, and methods for determining the position of interventional devices under MRI. A marker device is provided that utilizes an optical fiber, an acousto-optical sensor region that includes an electro-mechanical conversion assembly, and one or more antenna(e) The one or more antennae are configured to receive MRI radio-frequency (RF) electromagnetic energy and produce a corresponding electrical signal corresponding to the position. The acousto-optical sensor region may include a resonator and may be modulated by acoustic waves generated responsive to the electrical signal received from the one or more antennae The acousto-optical sensor region may be interrogated by light via the optical fiber to determine the position of the device for providing an active marker in the MRI image.

Disclosed is a method to remove distortion from a navigation system. The navigation system may be used to perform a procedure on a subject. The procedure may be any appropriate procedure. The navigation system may be used to account for the distortive effects of various conductive objects positioned near the subject on which the procedure is performed.

An apparatus includes a narrow elongate probe is adapted for insertion into the body of a living subject. The probe may be flexible and has a plurality of sensors consisting of single coils of very fine wire wound about a backbone of the probe, which transmit signals proximally via fine connecting wires to a position processor. The position processor analyzes the signals to determine position coordinates at multiple points along the length of the probe.

An apparatus for detecting low level pulses of millimeter wave electromagnetic radiation has an electromagnetic field receiver including: a receiving antenna configured to receive an input signal at one or more frequencies ranging from 10 GHz to 100 GHz, and a diode detector coupled to the receiving antenna, the diode detector providing an output voltage signal in response to the input signal. The apparatus also has an electronic signal processor. This produces an amplified voltage signal. The electronic signal processor also produces from the amplified voltage signal a reduced bandwidth, unipolar voltage signal proportional to a peak power of the input signal. The electronic signal processor uses this to produce an amplified reduced bandwidth, unipolar voltage signal. At least the electronic signal processor is encased in an electronically shielded housing.

A puncture planning apparatus has: a simulation unit that simulates movement of an organ and a puncture needle by simulation using an organ model; and a planning unit that plans, based on the simulation result, how to move the puncture needle when an actual organ is punctured. The simulation unit executes a plurality of times of the simulation of an operation to advance the puncture needle while correcting an angle of the puncture needle so as to follow the movement of the target segment due to deformation of the organ, conditions of an advancement speed of the puncture needle are changed for each of the plurality times of the simulation, and the planning unit performs planning using the best simulation result out of the plurality of simulation results acquired under different conditions of the advancement speed.

An embodiment in accordance with the present invention provides an improved electrically conductive transmission line that is radio frequency (RF) safe. The present invention does not include any inductive coupling elements. Instead, multiple coils constructed from twisted pairs of wires are used to block the common mode of the received magnetic resonance (MR) signal that can cause heating, while passing the differential mode that is used for tracking and/or imaging. These twisted pair coils are easily manufactured out of a single length of twisted pair wire, but multiple segments could also be used. The twisted pair coils of the present invention are easier to manufacture than the pre-existing inductive coupling element-based transmission lines, and occupy less overall volume inside a medical device. The individual coils of twisted pairs are tuned to the resonant frequency of the MR scanner by the addition of appropriate capacitors.

The disclosure relates to an ablation catheter for determining a local property of a biological tissue, said catheter having a flexible shaft, a data processing device, and an NMR sensor, which is arranged at the distal end of the shaft and is connected to the data processing device, wherein the NMR sensor comprises a first sensor element for generating a static magnetic field and a second sensor element for generating a magnetic alternating field, wherein the distal end of the shaft can be arranged adjacently to the point of the tissue to be measured, wherein the data processing device is designed to determine the local property of the tissue at this point on the basis of a signal of the NMR sensor transmitted to the data processing device. The disclosure also relates to a corresponding method.

A magnetic resonance tomography device and a method for equalized mapping in real time are provided. A first slice and a second slice are captured in three-dimensional (3D) encoding, where the first slice and the second slice are oriented to one another at an angle, and an instrument or trajectory to be mapped lies in an intersecting set of both the first slice and the second slice. A two-dimensional (2D) image may be generated alternately from both the first slice and the second slice and is displayed to a user.

Parallel transmit Magnetic Resonance MR scanner used to image a conductive object such as an interventional device like a guidewire within a subject. This is achieved by determining which Radio Frequency RF transmission modes produced by the parallel RF transmission elements couple with the conductive object and then transmitting at significantly reduced power so as to prevent excessive heating of the conductive object to an extent that would damage the surrounding tissue of the subject, for example, the coupling RF transmission modes may be generated at less than 30%, preferably around 10% of the normal power levels that would conventionally be used for MR imaging. However, even at these low power levels sufficient electric currents are induced in the conductive device to cause detectable MR signals; the location of the conductive object within the subject can thus be visualised. By fast alternate, or simultaneous, iterative application of low-power coupling mode and normal-power non-coupling modes, both the subject and the conductive object can be imaged. During the calibration step of determining which RF transmission modes couples with the conductive object, instead of physically measuring the current induced in the conductive object using sensors, imaging the conductive object using additional very short series of flip angle RF pulses (vLFA) gives a good approximation of the coupling matrix.

Embodiments of the present invention address the problems with previously known MRI enhancement resonators. The embodiments provide capacitances that are sufficiently large to result in resonance frequencies that are sufficiently low for medical MRI applications in devices that are sufficiently small for implantation into the body. Further, the capacitance and resonance frequency of the MRI enhancement resonator may be easily adjusted to particular desired values by selecting corresponding thin-film dielectrics, or thicknesses of such thin-film dielectrics. Moreover, the design and geometry of the embodiments provide MRI enhancement resonators with high Q-factors. The construction and material of such MRI enhancement resonators also yield flexible and biocompatible devices that are appropriate for applications involving implantation into the body.