117 results about "Correction for attenuation" patented technology

Imaging apparatus, is provided, comprising a first device, for obtaining a first image, by a first modality, selected from the group consisting of SPECT, PET, CT, an extracorporeal gamma scan, an extracorporeal beta scan, x-rays, an intracorporeal gamma scan, an intracorporeal beta scan, an intravascular gamma scan, an intravascular beta scan, and a combination thereof, and a second device, for obtaining a second, structural image, by a second modality, selected from the group consisting of a three-dimensional ultrasound, an MRI operative by an internal magnetic field, an extracorporeal ultrasound, an extracorporeal MRI operative by an external magnetic field, an intracorporeal ultrasound, an intracorporeal MRI operative by an external magnetic field, an intravascular ultrasound, and a combination thereof, and wherein the apparatus further includes a computerized system, configured to construct an attenuation map, for the first image, based on the second, structural image. Additionally, the computerized system is configured to display an attenuation-corrected first image as well as a superposition of the attenuation-corrected first image and the second, structural image. Furthermore, the apparatus is operative to guide an in-vivo instrument based on the superposition.

The fluid delivery system includes a pressurizing device for delivering injection fluid under pressure, a low pressure fluid delivery system, and a pressure isolation mechanism. The pressure isolation mechanism includes a first lumen associated with the pressurizing device, a second lumen associated with the low pressure fluid delivery system, and a pressure isolation port. The first valve is in a normally open position permitting fluid communication between the first lumen and the second lumen and movable to a closed position when fluid pressure in the first lumen reaches a predetermined pressure level. The first valve isolates the pressure isolation port from the first lumen in the closed position. A second valve is associated with the second lumen and regulates fluid flow through the second lumen. The second valve may be a disk valve defining one or more passageways in the form of slits through the body of the disk valve.

A combined PET and X-Ray CT tomograph for acquiring CT and PET images sequentially in a single device, overcoming alignment problems due to internal organ movement, variations in scanner bed profile, and positioning of the patient for the scan. In order to achieve good signal-to-noise (SNR) for imaging any region of the body, an improvement to both the CT-based attenuation correction procedure and the uniformity of the noise structure in the PET emission scan is provided. The PET/CT scanner includes an X-ray CT and two arrays of PET detectors mounted on a single support within the same gantry, and rotate the support to acquire a full projection data set for both imaging modalities. The tomograph acquires functional and anatomical images which are accurately co-registered, without the use of external markers or internal landmarks.

A method for correcting emission data from Positron Emission Tomography (PET) or SPECT includes generating a plurality of computed tomography (CT) image data, selecting a portion of the CT image data, processing the selected CT data to generate a plurality of attenuation correction (CTAC) factors at the appropriate energy of the emission data, weighting the CTAC factors to generate an emission attenuation correction map wherein the weights are determined based on the axial location and the slice thickness of the CT data and the axial location and the slice thickness of the PET or SPECT data, and utilizing the generated attenuation correction map to generate an attenuation corrected PET image.

Apparatus and methods for three dimensional image reconstruction from data acquired in a positron emission tomograph (PET). This invention uses a parallel/pipelined architecture for processing the acquired data as it is acquired from the scanner. The asynchronously acquired data is synchronously stepped through the stages performing histogramming, normalization, transmission/attenuation, Mu image reconstruction, attenuation correction, rebinning, image reconstruction, scatter correction, and image display.

Image quality deterioration due to a drop in resolution or lowering of S/N ratio while reducing the amount of data stored during a 3D data acquisition process, and shortening the time from the start of an examination to the end of imaging. The method and apparatus of this invention perform, in parallel with the 3D data acquisition process, addition of sinograms, reading of subsets of the sinograms having been added, and image reconstruction. Consequently, the amount of data stored is reduced, and the time from the start of an examination to the end of imaging is shortened. At the same time, since 3D iterative reconstruction is not accompanied by conversion from 3D data to 2D data, a drop in resolution due to errors occurring with the conversion from 3D data to 2D data is avoided. The 3D iterative reconstruction can directly incorporate processes such as an attenuation correction process. It is thus possible to avoid also a lowering of S/N ratio resulting from an indirect incorporation of such processes.

A method for correcting a positron emission tomography (PET) emission image is described. The method includes obtaining a PET emission sinogram of an object, obtaining a computed tomography (CT) image for a scanned portion of the object, the object having a truncated portion outside a field of view (FOV) of a CT image, determining a correction set of CT data based on a measured set of CT data within the CT sinogram, generating modified attenuation correction factors from the measured and correction sets of CT data, and correcting the PET sinogram using the modified attenuation correction factors.

The invention discloses an image attenuation correction method and device and belongs to the technical field of medical imaging. The image attenuation correction method comprises the steps that a first mode image is reconstructed according to first image data and is converted into an attenuation correction image; a second mode image of each gating phase is reconstructed according to second image data; image registration is conducted on the attenuation correction image and the second mode image corresponding to each gating phase to obtain an attenuation correction image of each gating phase; according to the attenuation correction image of each gating phase, the second mode image of each gating phase is reconstructed. The problem is solved that in the relevant art, the matching of PET and CT images is reduced due to the movement in the examination process or the physiological process of a subject, accordingly attenuation correction malposition of the PET images is likely to produce andattenuation artifacts are produced in the PET images, and the advantages of attenuation correction of PET data and quality improvement of PET images are achieved.

The DCC (Data Consistency Condition) algorithm is used in combination with MLAA (Maximum Likelihood reconstruction of Attenuation and Activity) to generate extended attenuation correction maps for nuclear medicine imaging studies. MLAA and DCC are complementary algorithms that can be used to determine the accuracy of the mu-map based on PET data. MLAA helps to estimate the mu-values based on the biodistribution of the tracer while DCC checks if the consistency conditions are met for a given mu-map. These methods are combined to get a better estimation of the mu-values. In gated MR/PET cardiac studies, the PET data is framed into multiple gates and a series of MR based mu-maps corresponding to each gate is generated. The PET data from all gates is combined. Once the extended mu-map is generated the central region is replaced with the MR based mu-map corresponding to that particular gate. On the other hand, in dynamic PET studies the uptake in the patient's arms reaches a steady state only after the tracer distributes throughout the body. Hence, for dynamic scans, the projection data of all frames is summed and used to generate the MLAA based extended mu-map for all frames.

The embodiment of the invention discloses a PET image reconstruction method, device and equipment and a medium. The method comprises the steps that a corresponding CT image and an unattenuated and corrected PET image are obtained based on organism scanning; and the CT image and the PET image which is not subjected to attenuation correction are input into a pre-trained neural network model to obtain an attenuation-corrected PET image. By the adoption of the technical scheme, the reconstruction speed of the PET image can be greatly increased, and therefore real-time preview of the PET image is achieved.

When a user instructs photographing by operating an operating unit, an image captured by an image sensor is stored as a photographed image in a memory. When a mode for performing color fading correction is set, the CPU instructs an image processing device to extract, from the photographed image, an area which is supposed to bring about color fading. The image processing device generates a binary image by detecting edges of the area.

The invention provides an imaging method. The imaging method comprise: CT picture is obtained by scanning with computer chromatography(CT); PET data is obtained by probing with positron emission chromatography(PET);the PET data is divided into a plurality of PTE data of expected phase position; according to the multiple PET data, unattenuated and uncorrected PED(NAC-PET) picture of corresponding expected phase position is respectively reconstructed; a NAC-PET picture in the multiple NAC-PET pictures of expected phase position, which is mostly matched with the CT picture, is confirmed and become a picture of reference expected phase position; other NAC-PET pictures of expected phase position are confirmed, the deformation field of the picture of reference expected phase position is confirmed; and at least according to the deformation field, the PET data is utilized to reconstructed PET pictures. The invention also discloses a imaging system.

In one embodiment, a method includes performing a magnetic resonance (MR) imaging sequence to acquire MR image slices or volumes of a first station representative of a portion of a patient; applying a first phase field algorithm to the first station to determine a body contour of the patient in the first station; identifying a contour of a first anatomy of interest within the body contour of the first station using the first phase field algorithm or a second phase field algorithm; segmenting the first anatomy of interest based on the identified contour of the first anatomy of interest; correlating first attenuation information to the segmented first anatomy of interest; and modifying a positron emission tomography (PET) image based at least on the first correlated attenuation information.

Apparatus for producing attenuation corrected nuclear medicine images of patients, comprising: at least one gamma camera head that acquires nuclear image data suitable to produce a nuclear tomographic image at a first controllable rotation rate about an axis; at least one X-ray CT imager that acquires X-ray data suitable to produce an attenuation image for correction of the nuclear tomographic image at a second controllable rotation rate about the axis; and a controller that controls the data acquisition and first and second rotation rates to selectively provide at least one of the following modes of operation: (i) a movement gated NM imaging mode in which the second rotation rate is substantially higher than the first rotation rate and the data from each view of the X-ray acquisition is associated with one of a plurality of respiration gated time periods; (ii) a cardiac gated NM imaging mode in which the second rotation rate is substantially higher than the first rotation rate and the data from each view of the X-ray acquisition for different rotations is averaged, wherein the X-ray data is not correlated with the cardiac cycle; and (iii) a cardiac gated NM imaging mode in which the second rotation rate is higher than the first rotation rate and the X-ray data is binned in accordance with a same binning as the NM data.

A detector detects gamma-rays emitted from inside an imaging region. An acquisition unit acquires a plurality of first projection data sets associated with a plurality of projection angles via the detector. An attenuation-correction unit attenuation-correct the plurality of first projection data sets based on a first CT image associated with the imaging region to generate a plurality of second projection data sets associated with the plurality of projection angles. An index calculation unit calculates an index based on the plurality of second projection data sets. The index is corresponding to a degree of positional offset between the imaging region at the time of acquisition of a plurality of third projection data sets associated with the first CT image and the imaging region at the time of acquisition of the plurality of first projection data sets.

A multiple modality imaging system 10 for cardiac imaging includes x-ray scanners 24,30 which acquires contrast enhanced CT projection data of coronary arteries with a laterally offset flat panel detector and SPECT imaging scanners 40a,40b, which share the same examination region and gantry as the x-ray scanners, acquires nuclear projection data of the coronary arteries. A CT reconstruction processor 34 generates a 3D coronary artery image representation, at least one planar coronary artery angiogram, and a 3D attenuation correction map from the acquired CT projection data. A SPECT reconstruction processor 44 corrects the acquired nuclear projection data based on the generated attenuation correction map and generates a SPECT image representation of the coronary arteries from the corrected nuclear projection data. A fusion processor 54 combines the nuclear image representation, the 3D vessel image representation, and the at least one planar vessel angiogram into a composite image.

An apparatus and methods for synthesizing a planar image from a three-dimensional emission dataset. The method includes acquiring a three-dimensional (3D) emission dataset of an object of interest, acquiring a three-dimensional (3D) attenuation map of the object of interest, determining a line or response that extends from an emission point in the 3D emission dataset, through the 3D attenuation map, to a pixel to be reconstructed on a planar image, integrating along the line of response to generate an attenuation corrected value for the pixel, and reconstructing the planar image using the attenuation correction value.

The invention relates to a tumor imaging quantitative detection technology, in particular to a method for quantitatively measuring a tumor standard uptake value, a thin body standard uptake value, a metabolic volume and total glucolysis through Coincidence SPECT or SPECT/CT and application of the method in tumor assessment. The implementation steps of the method comprise an image acquisition step, a scatter correction step, a nuclide physical decay correction step, a movement correction step, a tissue attenuation correction step, an image spatial resolution recovery step, a noise removal step, a standard uptake value calculation step and a tumor therapeutic effect assessment step. By means of the technological means of the Coincidence SPECT tumor imaging quantitative analysis technology and the application in tumor assessment, the clinical problem of quantitatively measuring the tumor standard uptake value, the thin body standard uptake value, the metabolic volume and the total glucolysis is solved through the Coincidence SPECT and the SPECT/CT, and the technology can be used in the clinical assessment of tumor.