Koninklijke Philips Corporation N.v.

Koninklijke Philips Electronics N.v.

Philips Intellectual Property & Standards Gmbh

Andy Ziegler

Thomas Koehler

Michael Grass

Roland Proksa

Tim Nielsen

Ewald Roessl

Ronny Ziegler

Levinus Pieter Bakker

Martinus Bernardus Van Der Mark

Bernhard Johannes Brendel

Dominic J Heuscher

Peter Koken

Claas Bontus

A device () for imaging the interior of an optically turbid medium is provided. The device comprises a receptacle () structured to accommodate an optically turbid medium for examination and an optically matching medium filling a space between an inner surface () of the receptacle () and the optically turbid medium. The device comprises at least one light source generating light to be coupled into the receptacle () and at least one detector for detecting light emanating from the receptacle (). A coupling surface () optically coupled to the inner surface () of the receptacle and a coupling member () optically coupled to the light source and the detector are provided. The coupling surface () and the coupling member () are movable to a plurality of different positions relative to each other and structured to establish an optical connection from the light source to the inner surface () of the receptacle and from the inner surface () of the receptacle to the at least one detector in the plurality of different positions.

Device for imaging the interior of an optically turbid medium and receptacle unit for such a device

The present invention relates to an imaging system for imaging a region of interest, wherein the imaging system comprises a projection data generation unit including a radiation source () and a detection unit () for acquiring projection data in different angular directions. The projection generation unit is adapted for acquiring projection data in an acquisition region on the detection unit. The imaging system further comprises a reconstruction unit () for reconstructing a first image of the region of interest from the acquired projection data and a forward projection unit () for forward projecting through the first image of the region of interest for calculating projection data corresponding to regions on the detection unit outside of the acquisition region. The reconstruction unit () is adapted for reconstructing a second image of the region of interest from the acquired projection data and from the calculated projection data.

Imaging system and imaging method for imaging a region of interest

A method for reconstructing a fluorescence image of the interior of a turbid medium is provided. The method comprises the step: accommodating a turbid medium () to which a fluorescent contrast agent has been administered in a measurement volume (). The fluorescent contrast agent is capable of emitting light in a first range of wavelengths upon irradiation with light. The method further comprises: performing attenuation measurements at a plurality of different wavelengths (&#x3bb;i, . . . , &#x3bb;k) by subsequently irradiating the turbid medium () with light from a plurality of different source positions and detecting light emanating from the turbid medium () in a plurality of detection positions for each source position; reconstructing absorption properties (&#x3bc;a(r, &#x3bb;) as a function of the position in the interior of the turbid medium () for the plurality of different wavelengths from the attenuation measurements; calculating absorption properties as a function of the position in the interior of the turbid medium () for wavelengths of the first range of wavelengths; performing a fluorescence measurement by subsequently irradiating the turbid medium () with light causing the fluorescent contrast agent to emit light in the first range of wavelengths from the plurality of source positions and detecting the light emanating from the fluorescent contrast agent in the plurality of detection positions for each source position; and reconstructing a fluorescence image of the spatial distribution of the fluorescent contrast agent in the interior of the turbid medium () from the fluorescence measurement using the calculated absorption properties.

Method for reconstructing a fluorescent image of the interior of a turbid medium and device for imaging the interior of a turbid medium

It is described a method for dynamically optimizing the signal-to-noise ratio of attenuation data related to two different X-ray energies for reconstructing an image of an object under examination. The method comprises (a) estimating the thickness and the material composition of the object at a plurality of different projection angles, (b) for each of the various projection angles calculating for a variety of combinations of different first and second X-ray energies a corresponding common signal-to-noise ratio, (c) for each of the various projection angles choosing the first and the second X-ray energy causing the maximum corresponding common signal-to-noise ratio, and (d) for each of the various projection angles acquiring X-ray attenuation data of the object whereby the two X-ray energies are the X-ray energies causing a maximum signal-to-noise ratio assigned to the respective projection angle.

Dynamic optimization of the signal-to-noise ratio of dual-energy attenuation data for reconstructing images

A computed tomography system includes an x-ray source () that rotates about and emits radiation through an imaging region (). At least one finite energy resolution detector () detects the emitted radiation. The at least one finite resolution detector () includes a plurality of sub-detectors (). Each of the plurality of sub-detectors () is associated with one or more different energy thresholds. Each of the energy thresholds is used to count a number of incident photons based on a corresponding energy level. A reconstruction system () reconstructs the photon counts to generate one or more images of a subject residing within the imaging region ().

Energy spectrum reconstruction

The invention relates to a device and a method for the iterative reconstruction of the attenuation coefficients &#x3bc;in a tomographic image of an object () from projection measurements m. In the update equation for &#x3bc;during the n-th iteration the backprojected error (m&#x2212;m&#x2212;(&#x3bc;)) is weighted by a voxel dependent factor Formula (I). Such a voxel dependent update may particularly be included in the algorithms of ART or ML.

Method and device for the iterative reconstruction of tomographic images

Iterative methods for reconstructing of three-dimensional images based on projection data signals obtained by a computer tomography system often result in wrong absorption coefficients in particular for regions including a hollow space of an object under examination. Furthermore iterative methods show a slow convergence for calculating such absorption coefficients. According to embodiments of the present invention there is provided a method for an advanced reconstruction of three-dimensional images based on modified projection data signals. The modification includes an addition of a constant absorption value to the measured projection data. Advantageously the constant absorption value is an absorption line integral through a virtual body having the spatial constant absorption coefficient of water. The virtual body preferably has a volume which is slightly bigger than the object of interest.

Advanced convergence for multiple iterative algorithm

The reconstruction of the energy distribution at a detector with a detector element that consists of many small pixels, which count the number of photons above certain thresholds, is performed with a Maximum Likelihood analysis, according to an aspect of the present invention. Thus, the reconstruction scheme may use the redundancy in the measurement and may treat the Poisson statistics accordingly.

Energy distribution reconstruction in CT

A tomographic apparatus () includes at least two x-ray sources () that rotate about and alternately emit radiation into an imaging region (). The at least two x-ray sources () emit radiation from a first set of angular positions during a first data acquisition cycle and from a different set of angular positions during a subsequent data acquisition cycle. At least two sets of detectors () detect primary radiation emitted by a corresponding one of the at least two x-ray sources () and produce data representative of the detected radiation. An interleaver () interleaves the data associated with the first and the subsequent data acquisition cycles for each of the at least two x-ray sources ().

Multi-tube imaging system reconstruction

A computed tomography system includes at least two x-ray sources (), a at least one common detector (), and a reconstruction system (). The at least two x-ray sources () are aligned at different z-axis locations at about a same angular position and concurrently emit radiation that traverses an imaging region (). The at least one detector () detects radiation emitted by the at least two x-ray source () and generates composite data indicative of the detected radiation. The reconstruction system () reconstructs the composite data to generate one or more images.

Stereo tube computed tomography

A computer tomography apparatus () for examination of an object of interest () comprising an electromagnetic radiation source () adapted to emit electromagnetic radiation to an object of interest (), a detecting device () adapted to detect electromagnetic radiation generated by the electromagnetic radiation source () and passed through the object of interest (), and a motion generation device () adapted to move the electromagnetic radiation source () and the detecting device () with respect to the object of interest () along a first trajectory and along a second trajectory which differs from the first trajectory, wherein the second trajectory is selected in such a manner that electromagnetic radiation detected during performing the second trajectory provides data which complete mathematically incomplete data detected during performing the first trajectory to thereby allow a reconstruction of structural information concerning the object of interest ().

Cone beam computed tomography with multiple partial scanning trajectories

It is described a method for reducing noise of X-ray attenuation data related to a first and second spectral X-ray data acquisition. The method comprises the steps of (a) acquiring data representing the X-ray attenuation behavior of a region of interest, (b) determining a first and a second attenuation-base line integral for the first and the second X-ray acquisition, respectively, and (c) calculating expected first and second signal to noise ratios for the first and the second attenuation-base line integral based on given signal to noise ratios for the first and second spectral X-ray data acquisition, respectively. The method further comprises the steps of (d) repeating the above mentioned steps of determining the attenuation-base line integrals and calculating the expected signal to noise ratios for a further first spectral X-ray data acquisition and (e) selecting improved spectral X-ray data acquisitions in order to enhance the overall signal to noise ratio of a final X-ray image.

Noise reduction in dual-energy X-ray imaging

The increasing cone angle of current high-end and future CT systems leads to a decrease in image quality if approximate cone-beam reconstruction methods are used. According to an exemplary embodiment of the present invention, an iterative four-dimensional cardiac CT reconstruction is provided, in which phase volumes are selected from the four-dimensional data set, each having the same spatial volume at different phase points. Corresponding voxels inside these phase volumes are then forward projected onto the same projection. After calculation of a different projection, these voxels are updated. This may provide for an efficient implementation of an iterative four-dimensional cardiac cone-beam CT reconstruction.

Efficient iterative four-dimensional cardiac cone-beam CT reconstruction

A radiographic imaging apparatus includes a radiation detector () and a radiation source () which projects a non-parallel beam of radiation into field of view (). A footprint of each voxel (v) which is projected on the detector () is corrected based on the position of the voxel (v) in the field of view () in relation to the radiation detector () and the radiation source (). The contributions from substantially parallel redundant projections are further combined based on a fractional distance frac from a center point () of the voxel (v) to a center of each of the adjacent redundant projections.

Image reconstruction with voxel dependent interpolation

A computer tomography apparatus () for examination of an object of interest (), the computer tomography apparatus () comprising detecting elements () adapted to detect electromagnetic radiation coherently scattered from an object of interest () in an energy-resolving manner, and a determination unit () adapted to determine structural information concerning the object of interest () based on a statistical analysis of detecting signals received from the detecting elements ().

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Hamburg, Germany

Andy Ziegler