U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Peter Bornert

Kay Nehrke

Tobias Schaffter

Mariya Ivanova Doneva

Michael Harald Kuhn

Holger Eggers

Bernd E Aldefeld

Markus Weiger

Tobias Klinder

Cristian Lorenz

Volker Rasche

Thomas Erik Amthor

Zhiqiang Hu

Peter Koken

George Randall Duensing

Christian Stehning

Kai-Michael Ludeke

Lingzhi Hu

The invention provides for a medical imaging system () comprising: a memory () for storing machine executable instructions (), a display () for rendering a user interface (), and a processor (). Execution of the machine executable instructions causes the processor to receive () three dimensional medical image data () descriptive of a region of interest () of a subject (). The region of interest comprises a spine (). Execution of the machine executable instructions further causes the processor to receive () a set of spinal coordinate systems () each descriptive of a location and an orientation of spinal vertebrae in the three dimensional medical image data. The set of spinal coordinate systems further comprises a set of spine centerline positions () each positioned on a spine centerline (). Execution of the machine executable instructions further causes the processor to receive () a mapping () between the set of spinal coordinate systems and a simplified coordinate system. The simplified coordinate system comprises a spinal height () descriptive of a position along the spine centerline. The simplified coordinate system further comprises a rotational orientation relative to a local vertebrae orientation. The simplified coordinate system further comprises an offset from the spine centerline. Execution of the machine executable instructions further cause the processor to repeatedly receive () a simplified coordinate () of the simplified coordinate system from the user interface. Execution of the machine executable instructions further cause the processor to repeatedly calculate () a spinal image rendering (). Calculating the spinal image rendering comprises using the mapping to transform the simplified coordinate into the set of spinal coordinate systems to determine an image location in the three dimensional medical image data. Execution of the machine executable instructions further cause the processor to repeatedly render () the spinal image rendering on the display.

Simplified navigation of spinal medical imaging data

The invention provides for a magnetic resonance imaging system () for acquiring magnetic resonance data () from a subject () within an imaging zone (). The magnetic resonance imaging system comprises a memory () for storing machine executable instructions (), and pulse sequence commands (), wherein the pulse sequence commands are configured to cause the magnetic imaging resonance system to acquire the magnetic resonance data according to a magnetic resonance fingerprinting technique. The pulse sequence commands are further configured to control the magnetic resonance imaging system to perform spatial encoding using a zero echo time magnetic resonance imaging protocol. Execution of the machine executable instructions causes the processor controlling the MRI system to: acquire () the magnetic resonance data by controlling the magnetic resonance imaging system with the pulse sequence commands; and calculate () a spatial distribution () of each of a set of predetermined substances by comparing the magnetic resonance data with a magnetic resonance fingerprinting dictionary ().

Silent 3D magnetic resonance fingerprinting

A medical imaging system () includes a nuclear imaging system (), a timing optimization unit (), a magnetic resonance (MR) scanner (), an MR reconstruction unit (), and an attenuation map unit (). The nuclear imaging system () receives nuclear decay data and generates at least one nuclear image () of a first resolution based on the received nuclear decay data of an imaged subject () and an attenuation map (). The timing optimization unit () which selects a first and a second echo time for a modified Dixon (mDixon) pulse sequence and a sufficient number of repetition times (TRs) to generate an image of the subject () of at least a first resolution, with the phase angle difference between water and fat at the first and the second echo time being unequal to 0&#xb0; and 180&#xb0;. The MR scanner () applies the sequence to the subject () and receives MR data () from the subject. The MR reconstruction unit () reconstructs at least one MR image () based on the MR data (). The attenuation map unit () constructs the attenuation map () based on the reconstructed MR image ().

MR-based attenuation correction in PET/MR imaging with Dixon pulse sequence

The invention relates to a method of MR imaging of an object () placed in the examination volume of a MR device (). It is the object of the invention to provide an improved MR-based temperature mapping method. The method of the invention comprises the steps of: subjecting the object () to an imaging sequence of RF pulses and switched magnetic field gradients, which imaging sequence is a stimulated echo sequence including: a) at least two preparation RF pulses (a) radiated toward the object () during a preparation period (), and b) one or more reading RF pulses (&#x3b2;) radiated toward the object () during an acquisition period () temporally subsequent to the preparation period (); acquiring at least two MR signals during the acquisition period (), wherein the two MR signals are either (i) a FID signal (I, FID) and a stimulated echo signal (I) or (ii) two stimulated echo signals (STE, STE*); and deriving a temperature map indicating the spatial distribution of the temperature within the object () from the at least two acquired MR signals. Moreover, the invention relates to a MR device () and to a computer program for a MR device ().

MR imaging with temperature mapping

The invention relates to a method of MR imaging of a body () of a patient. It is an object of the invention to provide a method that enables efficient compensation of flow artifacts, especially for MR angiography in combination with Dixon water/fat separation. The method of the invention comprises the steps of: a) generating MR echo signals at two or more echo times by subjecting the portion of the body () to a MR imaging sequence of RF pulses and switched magnetic field gradients, wherein the MR imaging sequence is a Dixon sequence; b) acquiring the MR echo signals; c) reconstructing one or more single-echo MR images from the MR echo signals; d) segmenting the blood vessels from the MR images; e) detecting and compensating for blood flow-induced variations of the amplitude or phase in the single-echo MR images within the blood vessel lumen, and f) separating signal contributions from water and fat spins to the compensated single-echo MR images. Moreover, the invention relates to a MR device () and to a computer program for a MR device ().

Dixon MR imaging with suppression of flow artifacts

The invention relates to a method of MR imaging of an object () placed in an examination volume of a MR device (). The method comprises the steps of: &#x2014;subjecting the object () to an imaging sequence comprising phase-modulated multi-slice RF pulses for simultaneously exciting two or more spatially separate image slices, &#x2014;acquiring MR signals, wherein the MR signals are received in parallel via a set of at least two RF coils () having different spatial sensitivity profiles within the examination volume, and &#x2014;reconstructing a MR image for each image slice from the acquired MR signals, wherein MR signal contributions from the different image slices are separated on the basis of the spatial sensitivity profiles of the at least two RF coils () and on the basis of the phase modulation scheme of the RF pulses. In order to optimize the conditioning of the inverse problem of the MR image reconstruction, the phase-modulation scheme of the RF pulses is derived from the spatial sensitivity profiles of the at least two RF coils (). Moreover, the invention relates to a MR device for carrying out this method as well as to a computer program to be run on a MR device.

Parallel multi-slice MR imaging using phase-modulated RF pulses

The invention relates to a method of performing coronary magnetic resonance angiography with signal separation for water and fat, the method comprising: acquiring coronary magnetic resonance angiography datasets using multi-echo Dixon acquisition, processing () the datasets for reconstruction of a first () and second () image data set, the first and second image data set comprising separate water and fat image data, wherein the processing of the datasets comprises a Dixon reconstruction technique.

Coronary magnetic resonance angiography with signal separation for water and fat

The invention relates to an MR method and an MR device for determining the position of at least one microcoil (11, 12) which is provided in or on an object (1) to be examined which is situated in an examination zone. During the acquisition of microcoil MR signals (S), at least one variable magnetic gradient field acts on the examination zone, so that the k space is scanned at scanning points (k.sub.x (t.sub.i), k.sub.y (t.sub.i)). The position (x, y) of the microcoil (11, 12) is determined from at least three scanning values (S(t.sub.i)) of a microcoil MR signal and the associated scanning points (k.sub.x (T.sub.i), k.sub.y (t.sub.i)) for example by solving a system of equations formed from these values. The MR method can be used for various scanning modes of the k space, and the acquisition of the microcoil MR signals (S) does not require any MR sequences other than the MR sequences required for determining the nuclear magnetization distribution in the examination zone.

MR method and MR device for determining the position of microcoil

A method of determining the spatial and/or spectral distribution of nuclear magnetization in separate regions (which are not coherent in respect of space or frequency) utilizes multi-dimensional RF pulses which are configured such that it is possible to determine the nuclear magnetization distribution in the individual regions from a linear combination of the MR signals occurring subsequent to an excitation (or from MR data derived therefrom). This results in shorter measuring times or a more attractive signal-to-noise ratio.

Method for determining the spatial and/or spectral distribution of

The invention relates to an MR method with reduced motion artefacts in which the displacement of a pulsating object, or of a part thereof, which is present in an examination zone is continuously measured relative to a reference position, and in which the reconstruction of an MR image utilizes exclusively MR signals acquired from the examination zone while the displacement from the reference position reaches or falls below a threshold value. This gating is enhanced in accordance with the invention in that prior to the acquisition of the MR signals there are generated phase encoding gradients k.sub.y) which act on the examination zone with different time integrals and that the threshold value (v.sub.s) can be varied in dependence on the respective phase encoding gradient (k.sub.y).

MR method with reduced motion artefacts

The position of an object, for example a catheter, in a body to be examined is determined so as to enable monitoring of its movement through the body at the same time that information concerning the anatomy in the surroundings of the object is to be acquired. An as high as possible temporal and spatial resolution should be achieved for this purpose. To this end, the nuclear magnetization in the surrounding region of the object is determined by means of a micro-coil which is mounted on the inserted object, it being possible to determine the position of the object from the nuclear magnetization. Subsequently, an RF coil system is used to perform a line scan around this position in order to determine the nuclear magnetization in a line-shaped region.

MR method and arrangement for carrying out the method

In an MR method whereby artefacts can be eliminated in MR images of inclined slices which are situated outside the isocenter, the temporal variation of a phase error is calculated from the imposed (desired) variation of the magnetic gradient fields and the impulse responses of the gradient coil sub-systems generating these fields, and the measured MR signals are corrected accordingly.

MR method and device for carrying out the method

In an MR spectroscopy method nuclear magnetization of a plurality of voxels present at an area of intersection of two slices is simultaneously excited by repeated sequences, the resultant phase encoding of the voxels is varied from one sequence to another, and a spectral distribution of nuclear magnetization in the voxels is derived from linear combinations of the MR signals generated in the individual sequences. A method is obtained wherein each sequence a first slice-selective RF pulse is generated in order to excite the transverse magnetization in one or more first slices, and subsequently a second slice-selective RF pulse is generated in order to refocus nuclear magnetization in one or more second slices which intersect the first slices at an angle other than zero, and in the various sequences the MR signals produced by the spin echos in the voxels present at the area of intersection of each first and second slice is detected and used to determine the spectral distribution of the nuclear magnetization.

MR spectroscopy method for measuring plural voxels at intersections of

A magnetic resonance method for imaging a curved portion of a body in which only MR signals in the curved portion of the body are generated by pulse sequences which include RF pulses and temporary magnetic fields. From the received MR signals an image of the curved portion can be reconstructed by use of linear transformations.

Method and device for imaging a curved region by means of magnetic

A magnetic resonance (MR) method utilizes a plurality of inductively coupled receiving coil systems quasisimultaneously to measure a nuclear magnetization distribution in an examination zone. The method involves excitation of the nuclear magnetization in an examination zone, exposed to a uniform, steady magnetic field, by means of at least one RF pulse, multiple rephasing of the exited nuclear magnetization in order to generate a plurality of MR echo signals whose number at least equals the number m of receiving coil systems, and switching over the receiving coil systems in such a manner that, subsequent to said excitation, each receiving coil system receives at least one MR echo signal while at the same time alii respective other coil systems are inactive.

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Hamburg, Germany

Peter Bornert