A magnetic resonance imaging (MRI) system that can be operated while a subject performs, experiences, or otherwise undergoes naturalistic motion. This movable MRI (mMRI) system includes a magnet whose position and orientation can be changed while the subject is moving, such that the magnet and subject maintain a substantially fixed spatial relationship relative to each other.

In a method and device for generating 4D flow images by operation of a magnetic resonance system, a volume flow data record is recorded, wherein the flow is encoded in a single direction. This is subsequently repeated with all the flow encoding directions. From the raw data associated with the individual flow encoding directions, phase images and magnitude images are calculated. Deformation fields are calculated on the basis of the magnitude images. The deformation fields are applied to the calculated phase images. Finally, a 4D flow velocity field is calculated, on the basis of a phase difference reconstruction of the corrected phase images.

Described here are systems and methods for a robust magnetic resonance elastography (MRE) imaging platform for rapid dynamic 3D MRE imaging. The imaging platform includes an MRE pulse sequence and advanced image reconstruction framework that work synergistically in order to greatly expand the domains where MRE can be deployed successfully.

The invention provides for a medical instrument (200, 400, 500) comprising a magnetic resonance imaging system (202), a transducer (222) for mechanically vibrating at least a portion of the subject within the imaging zone. Instructions cause a processor (236) controlling the medical instrument to: control (100) the transducer to vibrate; control (102) the magnetic resonance imaging system to repeatedly acquire the magnetic resonance data (252) using a first spatially encoding pulse sequence (250); control (104) the magnetic resonance imaging system to acquire navigator data (256) using a second spatially encoding pulse sequence (254); construct (106) a set of navigator profiles (258, 804, 904, 1004, 1108, 1208, 1308) using the navigator data; determine (108) at least one parameter (260) descriptive of transducer vibrations using the set of navigator profiles; and reconstruct (110) at least one magnetic resonance rheology image (262) from the magnetic resonance data.

An object of the invention is to perform MRI imaging which is less likely to be affected by a body motion without prolonging an imaging time. The control unit takes in images captured by the camera at a predetermined frame rate. The imaging pulse sequence is divided into small sequences at a time width corresponding to the frame rate of the camera. The control unit, before causing the imaging unit to execute one small sequence, detects a displacement of the subject with respect to a predetermined reference position or a motion speed of the subject based on an image of the latest frame, and causes the imaging unit to execute the small sequence when a detection result is within a predetermined allowable range and waits until an image of a next frame is taken in according to the frame rate without causing the imaging unit to execute the small sequence when the detection result exceeds the allowable range.

Example access devices, treatment devices, and kits useful in performing treatment under magnetic resonance imaging and related methods are described. An example access device includes an elongate tubular member formed of an MRI compatible material and moveable between a first, unexpanded configuration and a second, expanded configuration. The elongate tubular member has a central lengthwise axis, a proximal end, a distal end, an axial length, and a main body that defines a circumferential wall, a lumen, a proximal opening, a distal opening, and a main body opening. The main body opening is arranged in a spiral relative to the lengthwise axis and extends circumferentially along the circumferential wall. The main body opening extends along the entire axial length of the elongate tubular member from the proximal end to the distal end.

Described here are systems and methods for a robust magnetic resonance elastography (MRE) imaging platform for rapid dynamic 3D MRE imaging. The imaging platform includes an MRE pulse sequence and advanced image reconstruction framework that work synergistically in order to greatly expand the domains where MRE can be deployed successfully.

A system for margin assessment of an ex-vivo tissue (25) is provided, including a magnetic resonance imaging (MRI) scanner (14) controlled by a control unit (12), and a tissue container (24) for holding a sample of an ex-vivo tissue (25). The MRI scanner (14) includes a coil-magnet assembly (31) including magnets (34), wherein the tissue (25), placed in the container (24), is placed under a constant static magnetic field (Bo), which is induced by the magnets (34), and the container (24) is positioned so the sensitive region is within a measured field of view (FOV) excited by one or more transmit/receive coils (38) operative to generate a time-varying RF B1 electro-magnetic field pointing towards the tissue (25), and wherein the container (24) is fixed on a moving table (40).

A PET/MRI device includes an MRI device that has a measurement port, a PET detector that can be inserted into the measurement port, and a mechanism that can slide the PET detector into and out of the MRI measurement port. Thereby, the PET/MRI device allows MRI measurement during PET measurement.

A static magnetic field generator generates a non-magnetic field region. An AC magnetic field application instrument applies an AC magnetic field to the non-magnetic field region. A detection coil has an axis parallel to a direction of the AC magnetic field in order to detect a magnetization signal. A measuring instrument is connected to the detection coil. A resonance frequency variable device includes a capacitor connected in parallel to the detection coil in order to adjust a resonance frequency of the detection coil and the measuring instrument. A capacity of the capacitor is adjusted such that a resonance frequency of a closed circuit including the detection coil, the measuring instrument, and the resonance frequency variable device including the capacitor coincides with a frequency of a harmonic signal.