Koninklijke Philips Corporation N.v.

Christian Stehning

Peter Boernert

Julien Senegas

Stefanie Remmele

Sascha Krueger

Ulrich Wolfgang Katscher

Zhiqiang Hu

Jochen Keupp

Michael Helle

Lingzhi Hu

Jurgen Edwin Rahmer

Steffen Weiss

Miha Fuderer

Daniel Wirtz

Holger Eggers

Lingxiong Shao

Heinrich Schulz

Kay Nehrke

Steffen Renisch

Mariya Ivanova Doneva

Nicole Schadewaldt

Peter Mazurkewitz

Thomas Heiko Stehle

Peter Bornert

Klaas P Pruessmann

Jürgen Erwin Rahmer

Astrid Ruth Franz

Tobias Richard Schaeffter

Thomas Francis Perkins

Tobias Ratko Voigt

Bertram Wilm

Wei Liu

Ulrike Blume

The invention provides for a medical instrument () comprising a camera system (″) for imaging a portion () of a subject () reposing on a subject support (). The medical instrument further comprises a display system () for rendering a position feedback indicator (). The display system is configured such that the position feedback indicator is visible to the subject when the subject is reposing on the subject support. The execution of the machine executable instructions () causes a processor () controlling the medical instrument to: acquire () a base position image () using the camera system; repeatedly () acquire a subsequent image () using the camera system; repeatedly () calculate an image transformation () from voxels of at least a portion of the base position image to voxels of the subsequent image by inputting the base position image and the subsequent image into an image transformation algorithm (); and repeatedly () render a position feedback indicator () on the display, wherein the position feedback indicator is controlled by the image transformation.

Position feed back indicator for medical imaging

The invention provides for a medical apparatus () comprising an optical imaging system () configured for acquiring a series of optical images () descriptive of cardiac motion of a subject (). The medical apparatus further comprises a memory () for storing machine executable instructions (). The medical apparatus further comprises a processor () for controlling the medical apparatus. Execution of the machine executable instructions causes the processor to repeatedly: acquire () a series of images using the optical imaging system, wherein the series of images are acquired at a rate of at least 10 frames per second; and derive () a cardiac motion signal () from the series of images, wherein the cardiac motion signal is derived by tracking motion of at least a group of pixels within the series of images.

Cardiac motion signal derived from optical images

The invention relates to a method of Dixon-type MR imaging. It is an object of the invention to provide a method that enables efficient and reliable Dixon water/fat separation, in particular using a bipolar acquisition strategy, while avoiding flow-induced leakage and swapping artifacts. According to the invention, an imaging sequence is executed which comprises at least one excitation RF pulse and switched magnetic field gradients, wherein pairs of echo signals are generated at two different echo times (TE, TE) and during two or more different cardiac phases (AW, AW). The echo signals are acquired and phase images are reconstructed therefrom. A final diagnostic image is reconstructed from the echo signal data using water/fat separation, wherein regions of flow and/or or estimates of flow-induced phase errors are derived from the phase images to suppress or compensate for flow-induced leakage and/or swapping artifacts in the final diagnostic image. Therein, flow-induced phase offsets are determined by voxel-wise comparison of the phase images associated with the different cardiac phases. Moreover, the invention relates to a MR device () and to a computer program to be run on a MR device ().

MR imaging using Dixon-type water/fat separation with suppression of flow-induced leakage and/or swapping artifacts

A magnetic resonance imaging system that includes machine executable instructions to control the system with pulse sequence commands to acquire a series of magnetic resonance data and noise magnetic resonance data. The pulse sequence commands are configured to control the system to acquire a series of magnetic resonance data from a subject according to a quantitative magnetic resonance imaging protocol for quantitatively determining a relaxation time. The quantitative magnetic resonance imaging protocol includes pulse sequence repetition having a magnetic gradient portion, a radio frequency portion, and an acquisition portion. The quantitative magnetic resonance imaging protocol includes a pause cycle between at least two of the multiple pulse sequence repetitions, wherein the pulse sequence commands are configured for acquiring noise magnetic resonance data during the pause cycle using the magnetic gradient portion and the acquisition portion.

Quantitative measurement of relaxation times in magnetic resonance imaging

It is an object of the invention to improve tissue classification in MRI images. In particular it is an object of the invention to improve the classification of bone and air in MRI images. This object is achieved by a method for tissue classification in a region of interest in a magnetic resonance (MR) image comprising a first region and a second region, wherein the first region represents air and the second region represents bone. The method comprises the steps of: &#x2014;acquiring a first magnetic resonance image comprising the first and the second region and; &#x2014;acquiring a second magnetic resonance image comprising the first and the second region, wherein the first region has a different shape in the second magnetic resonance image compared to the first magnetic resonance image and; &#x2014;identifying the first region and second region in the first and second image and; &#x2014;comparing the first image and the second image with respect to the first region and the second region and; &#x2014;classifying the first region as region representing air based on a presence of a shape difference between the first and the second image and classifying the second region as bone based on an absence of the shape difference between the first and second image.

Method for tissue classification, computer program product and magnetic resonance imaging system

A magnetic resonance imaging system includes a gradient system and a processor for controlling the magnetic resonance imaging system. Execution of machine executable instructions causes the magnetic resonance imaging system to: acquire by coil elements first magnetic resonance data simultaneously from a group of passive local probes, wherein the first group of passive local probes includes a plurality of passive local probes located spaced apart from each other; disentangle contributions to the first magnetic resonance data from the individual local probes, calculate for the magnetic resonance imaging system a gradient impulse response function of the gradient system using the first magnetic resonance data from the local probes; and determine correction factors using the gradient impulse response function

Gradient impulse response function mapping

A medical apparatus () includes a magnetic resonance imaging system () for acquiring magnetic resonance data () from an imaging zone (); a processor () for controlling the medical apparatus; a memory () storing machine executable instructions (). Execution of the instructions causes the processor to: acquire () the magnetic resonance data using a pulse sequence () which specifies an echo time greater than 400 &#x3bc;s; reconstruct () a magnetic resonance image using the magnetic resonance data; generate () a thresholded image () by thresholding the magnetic resonance image to emphasize bone structures and suppressing tissue structures in the magnetic resonance image; and generate () a bone-enhanced image by applying a background removal algorithm to the thresholded image.

Detection of bone tissue using magnetic resonance imaging

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

A magnetic resonance imaging system () includes at least one processor () configured to receive () diffusion weighted imaging data based on a diffusion weighted imaging sequence with magnetic gradient fields applied in different directions and with different b-values. The at least one processor () is further configured to detect () motion corrupted data present in the received imaging data based on a comparison of data redundant in the received data, and substitute () alternative data for detected motion corrupted data.

Motion detection and correction method for magnetic resonance diffusion weighted imaging (DWI)

A medical imaging system () includes a magnetic resonance (MR) scanner (), and a MR reconstruction unit (). The MR scanner () applies a multi-echo ultra-short TE (UTE) with mDixon pulse sequence to a subject () and receives MR data () representing at least a portion of the subject. The MR reconstruction unit () reconstructs a Free Induction Decay (FID) image (), and one or more echo magnitude images (), one or more phase images (), an in-phase image (), a water image (), and a fat image () from the received MR data ().

Differentiating tissues with MR imaging

An electric properties tomography method for reconstructing a spatial distribution of electric conductivity (&#x3c3;) from magnetic resonance image data representative of a magnetic resonance image of at least a portion of a subject of interest (), the spatial distribution covering at least a portion of the area of the magnetic resonance image, and the method comprising following steps:&#x2014;segmenting the magnetic resonance image,&#x2014;extrapolating acquired phase values, &#x2014;replacing acquired phase values by the extrapolated phase values,&#x2014;transforming into the frequency domain,&#x2014;multiplying a frequency domain-transformed numerical second derivative by the acquired phase values and the frequency domain-transformed numerical second derivative by the extrapolated phase values, respectively, and&#x2014;transforming the result of the multiplying into the spatial domain. Also covered are a corresponding MRI system and a software module.

EPT method of electric conductivity reconstruction with enhanced stability and speed

A magnetic resonance imaging method includes acquisition of datasets of magnetic resonance data from an object. At least some of the datasets are undersampled in k-space. Each dataset relating to a motion state of the object. Images are reconstructed from each of the datasets by way of a compressed sensing reconstruction. Motion correction is applied to the reconstructed images relative to a selected motion state, so as to generate motion corrected images. A diagnostic image for the selected motion state is derived, e.g. by averaging from the motion corrected images.

Magnetic resonance imaging of object in motion

The invention relates to a magnetic resonance imaging method for simultaneous and dynamic determination of a longitudinal relaxation time Tand a transversal relaxation time Tof the nuclear spin system of an object, in the context of DCE or DSE MRI. In this respect, the invention makes use of a steady-state gradient echo pulse sequence comprising an EPI readout module.

Simultaneous and dynamic determination of longitudinal and transversal relaxation times of a nuclear spin system

A medical imaging system () includes a workstation (), a coarse segmenter (), a fine segmenter (), and an enclosed tissue identification module (). The workstation () includes at least one input device () for receiving a selected location as a seed in a first contrasted tissue type and a display device () which displays a diagnostic image delineating a first segmented region of a first tissue type and a second segmented region of a second contrasted tissue type and identified regions which include regions fully enclosed by the first segmented region as a third tissue type. The coarse segmenter () grows a coarse segmented region of coarse voxels for each contrasted tissue type from the seed location based on a first growing algorithm and a growing fraction for each contrasted tissue type. The seed location for growing the second contrasted tissue type includes the first coarse segmented region and any fully enclosed coarse voxels, and each coarse voxel includes an aggregation of voxels and a maximum and a minimum of the voxel intensities. The fine segmenter () grows a segmented region of voxels for each contrasted tissue type from the seed location and bounded by the second coarse segmented region based on a second growing algorithm and a growing fraction for each contrasted tissue type initially set to the growing fraction for the corresponding region. The seed location for growing the second contrasted tissue type includes the first segmented region and any identified regions. The enclosed tissue identification module () identifies any regions of voxels fully enclosed by the first segmented region as being of the third tissue type. The coarse segmenter, the fine segmenter, and the enclosed tissue identification module are implemented by an electronic data processing device.

Tumor segmentation and tissue classification in 3D multi-contrast

A magnetic resonance system comprises a magnetic resonance scanner () including a main magnet () generating a static magnetic field biasing nuclear spins toward aligning along a direction of the static magnetic field, magnetic field gradient coils (), a radio frequency coil (), and a controller () configured to: (a) drive the radio frequency coil to selectively tip spins predominantly of short T2* out of the direction of the static magnetic field; (b) drive at least one of the magnetic field gradient coils and the radio frequency coil to dephase said spins predominantly of short T2* tipped out of the direction of the static magnetic field; and (c) drive the magnetic field gradient coils and the radio frequency coil to acquire magnetic resonance data that is predominantly T2* weighted due to preceding operations (a) and (b).

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Hamburg, Germany

Christian Stehning