Patent classifications
G01R33/287
Rod-shaped body and medical instrument
The invention relates to a rod-shaped body comprising a central section and a peripheral section, wherein the central section is arranged in the center of the rod-shaped body and is enclosed by the peripheral section. Both the central section and the peripheral section substantially extend along the entire length of the rod-shaped body. The central section comprises at least one non-metallic fiber bundle that is embedded in a non-ferromagnetic matrix material. The matrix material is doped with marker particles. The peripheral section comprises at least one undoped, non-ferromagnetic matrix material. The diameter of the central section is less than or equal to 0.2 mm, preferably less than or equal to 0.15 mm, and even more preferably, less than or equal to 0.1 mm, and in particular less than or equal to 0.08 mm.
Method and system for magnetic resonance imaging
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.
Placement manipulator and attachment for positioning a puncture instrument
An apparatus (51) includes a needle placement manipulator (1) and an attachment (52) for the manipulator. The manipulator includes a needle holder and a rotary mechanism. The rotary mechanism (3, 4) has a remote center of motion (RCM: 11) and is configured to position a needle holder (5) such that the axis of the needle holder traces a conical region of coverage (108), the conical region of coverage having the apex thereof at the RCM and the base thereof in a direction towards a subject of needle placement (14). The attachment supports the guide mechanism and is configured to be mounted onto the subject of needle placement. The attachment includes a guide portion (183c) configured to change an inclination of the rotary mechanism with respect to the subject of needle placement such that the axis of the needle holder intersects an insertion target (14) located outside of the conical region of coverage.
Tracking a marker in an examination subject by a magnetic resonance tomograph
A magnetic resonance tomograph and a method for tracking a marker in an examination subject by a magnetic resonance tomograph are disclosed. The magnetic resonance tomograph includes a first image recording mode for acquiring the position of the marker. In one act of the method, data for acquiring the position of the marker is recorded with the first image recording mode. In a further act, a position of the marker is determined from the data and a first image with a location-accurate reproduction of the marker is prepared. The recording of the data for acquiring the position of the marker takes place depending on an event.
Enlargement of tracking volume by movement of imaging bed
A medical system, includes an imaging apparatus, which includes an array of detectors, which define an imaging volume and form images of a region within a body of a patient that is positioned in the imaging volume. A movable bed transports the body of the patient through the imaging volume. An invasive probe is inserted into a lumen within the body of the patient. A tracking apparatus includes a field transducer positioned in the imaging apparatus and defining a tracking volume within the imaging apparatus, and generates an indication of a location of the invasive probe within the tracking volume responsively to an interaction between the field transducer and the invasive probe. A controller controls the movable bed in response to the location of the invasive probe indicated by the tracking apparatus.
Surgical image-guided navigation devices and related systems
MRI compatible localization and/or guidance systems for facilitating placement of an interventional therapy and/or device in vivo include: (a) a mount adapted for fixation to a patient; (b) a targeting cannula with a lumen configured to attach to the mount so as to be able to controllably translate in at least three dimensions; and (c) an elongate probe configured to snugly slidably advance and retract in the targeting cannula lumen, the elongate probe comprising at least one of a stimulation or recording electrode. In operation, the targeting cannula can be aligned with a first trajectory and positionally adjusted to provide a desired internal access path to a target location with a corresponding trajectory for the elongate probe. Automated systems for determining an MR scan plane associated with a trajectory and for determining mount adjustments are also described.
MAGNETIC TRANSMITTERS FOR A MAGNETIC TRACKING SYSTEM
Apparatus, having a frame encompassing a volume. The apparatus includes three pairs of separated planar conductive coils, the separated coils of each pair having a common axis of symmetry, the three pairs being attached to the frame so that the common axes of symmetry are mutually orthogonal, and so that the coils surround the volume. An alternating current power supply is coupled to drive the separated coils of each pair in anti-phase so as to generate a magnetic field having a preset spatial variance over the volume. The apparatus also includes a probe that is configured to enter the volume and that has a sensor coupled to generate a signal responsive to a temporal rate of change of the magnetic field and to the preset spatial variance thereof. A processor is configured to receive the signal and in response formulates a position of the probe within the volume.
Automatic multimodal real-time tracking of a moving marker for image plane alignment inside a MRI scanner
- UNIVERSITE DE STRASBOURG (ETABLISSEMENT PUBLIC NATIONAL A CARACTERE SCIENTIFIQUE, CULTUREL ET PROFESSIONNEL) ,
- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (ETABLISSEMENT PUBLIC NATIONAL A CARACTERE SCIENTIFIQUE ET TECHNOLOGIQUE) ,
- INSTITUT HOSPITALO-UNIVERSITAIRE DE CHIRURGIE MINI-INVASIVE GUIDEE PAR L'IMAGE (FONDATION DE COOPERATION SCIENTIFIQUE APPROUVEE PAR DECRET MINISTERIEL DU 25 NOVEMBRE 2011 PUBLIE AU JOURNAL OFFICIEL DU 27 NOVEMBRE 2011)
A system for an automatic multimodal real-time tracking of moving instruments for image plane alignment inside an MRI scanner includes: an MRI scanner, an MRI multi-plane pulse sequence generating unit allowing to interactively modify the position and orientation of one or several image planes in real-time, one or several external optical sensors with high frame rate, preferably a RGB-D sensor or other similar camera system like a stereovision systems, a multimodal marker including at least one MR visible feature and one visual feature able to be tracked by both the MRI scanner and the at least one external optical sensor, a computer for processing in real-time images from both MRI and optical sensor to fuse the detected marker position and orientation or pose from both modalities, and predict the next image plane position and orientation based on the estimated motion of the moving marker.
Method and apparatus visualizing a medical object
In a method and apparatus for visualizing the position of a medical object in a body of an examination object, a stack of sectional images through the body, acquired by operation of a magnetic resonance imaging system, is provided to a processor, which implements sectional-image-specific pixel coding of the sectional images. This is followed by the creation of a combination image composed of a combination of a number of coded sectional images from the stack, and representation of the combination image.
Method and magnetic resonance apparatus for monitoring an interventional procedure conducted with an intervention tool
In a method and magnetic resonance (MR) apparatus for monitoring an interventional procedure with an intervention tool in a vessel of an examination subject, the intervention tool is moved in an insertion direction in the vessel and the position of a front end of the intervention tool in the insertion direction is determined. A first volume segment is determined dependent on the position and the flow direction of a fluid within the vessel. An RF saturation pulse is radiated into the first volume segment that saturates nuclear spins in the fluid within the first volume segment. MR data are acquired in a second volume segment, which contains the front end of the intervention tool and a region in front of the intervention tool in the insertion direction. An MR image is generated from the acquired MR data.