33 results about "For Attenuation Correction" patented technology

A method of producing a nuclear medicine image of a subject comprising the steps of acquiring nuclear image data suitable to produce a nuclear tomographic image, the data being acquired by at least one gamma camera head (12, 14) rotating about the subject at an average first rate, acquiring x-ray imaging data suitable to produce an x-ray tomographic image for attenuation correction of the gamma camera image, the data being acquired by an array of detectors (20) irradiated by an x-ray source (18) rotating around the subject at an average second rate which is within a factor of 10 of the first rate, and reconstructing an attenuation corrected nuclear medicine image utilizing the nuclear imaging data and x-ray imaging data.

Methods and systems for imaging a patient are provided. The method includes scanning a patient and acquiring a plurality of frames of cine computed tomography (CT) images during one complete respiratory cycle. In one embodiment, a method is provided that includes selecting an organ of interest in the cine CT data and selecting a value for each pixel in the organ of interest that represents the maximum density measurement. An attenuation corrected positron emission tomography (PET) image is constructed based on the maximization of the pixel intensity of the organ of interest in the CT attenuation correction map. Incorrect attenuation correction values for PET images can be avoided by utilizing the CT attenuation correction map.

Emission contamination data are collected in a shifted mock scan simultaneous with the collection of transmission data during a transmission scan of a patient with a collimated gamma point source, the transmission data are corrected with the emission contamination data, and the corrected transmission data are used for attenuation correction of emission data for reconstruction of an emission image of the patient. In a preferred implementation, when the point source is at a particular axial location and illuminates an axial beamwidth of “Fz” over the gamma detector, emission contamination data are collected from the gamma detector over an axial separated region “Fz′” having about the same axial extent but axially displaced by about half of the axial field of view (FOV).

The invention relates to MR scan selection for PET attenuation correction. A method of attenuation correction for a positron emission tomography (PET) system (52) includes: obtaining PET scan data representative of a volume scanned by the PET system (52); obtaining a plurality of magnetic resonance (MR) scan data sets representative of the volume, each MR scan data set being acquired in a respective time period during acquisition of the PET scan data by the PET system; detecting motion of the volume that occurred during the acquisition of the PET scan data based on an assessment of the plurality of MR scan data sets, the PET scan data, or the plurality of MR scan data sets and the PET scan data; determining attenuation correction data from the plurality of MR scan data sets based on the detected motion for alignment of the attenuation correction data and the PET scan data; and correcting the PET scan data with the attenuation correction data.

The invention relates to an acquisition method of a PET image attenuation coefficient and a method and system for attenuation correction. Under the circumstance based on regional CT scanning, the CT value of a first sub region, for example, a tone tissue, can be objectively acquired by means of a mapping relationship between the CT value of the CT scanning region and the pixel value of a PET scanning region, and a first attenuation coefficient of the first sub region is quantificationally acquired according to the CT value of the first sub region. Compared with direct assignment on the attenuation coefficient on the first sub region of the bone tissue after image cutting, the result is more accurate and reliable.

A method for attenuation correction of a phantom image in a PET imaging system includes obtaining raw scan data of a scanned phantom, a non attenuation corrected template image of a stock phantom of like type to the scanned phantom, and an attenuation map of the stock phantom. The method further includes generating a non-attenuation corrected raw image of the scanned phantom based on the raw scan data, registering the template image and attenuation map to the raw image through a rigid image transform, and applying the registered attenuation map to the raw scan data to enable reconstruction of an attenuation corrected final image.

In a method for attenuation correction of emission tomography scan data acquired from an examination object in a combined magnetic resonance emission tomography apparatus, wherein an interference object is situated in the examination region, which causes a magnetic interference field during combined magnetic resonance emission tomography imaging, magnetic resonance scan data of the examination object are acquired by executing a magnetic resonance sequence designed to at least partially compensate inference due to the magnetic interference field. Emission tomography scan data are acquired and an attenuation map is generated using the acquired magnetic resonance scan data. Attenuation correction of the emission tomography scan data is implemented using the generated attenuation map.

A method and apparatus of image reconstruction attenuation correction in PET or SPECT cardiac imaging is provided. A volumetric attenuation imaging scan by an X-ray source may be used to generate a gamma ray attenuation map. The volumetric attenuation imaging scan may be randomized, and may be performed while the imaged subject is breathing.

A method for attenuation correction of a plurality of time-gated PET images of a moving structure includes establishing an ACF matrix, based on a baseline MR image of the structure; developing a plurality of image transforms, each of the image transforms registering the baseline MR image to a respective cine MR image of the moving structure; applying each of the image transforms to the ACF matrix to generate a corresponding cine ACF matrix; time-correlating each of the cine MR images, and its corresponding cine ACF matrix, to one of the plurality of time-gated PET data sets; and producing from each of the time-gated PET data sets an attenuation-corrected time-gated PET image.

A positioning method of a CT image for PET attenuation correction comprises the following steps: (1) acquiring Dicom image data scanned by a CT, and determining a maximum inspection region C1MAX to C2MAX from the Dicom image data; 2) determining that a range of a PET image to be corrected in the Z-axis is P1 to P2, and determining a relative difference delta between positions of the CT and a PET examining table to determine that an initial value range of a target CT image in the Z-axis is P1-delta to P2-delta, (3) traversing the Dicom data of the CT image, determining index values CIndex1 to CIndex2 corresponding to the Z-axis position of the target CT image at the P1-delta to the P2-delta, wherein the CIndex1 is a maximum value index where the Z-axis position of the target CT image is less than a Z-axis minimum value of the PET image, the CIndex2 is a minimum value index where the Z-axis position of the target CT image is greater than the Z-axis minimum value of the PET image, and theCT image between the CIndex1 and the CIndex2 is a value range of the target CT image. The positioning method can effectively determine the number of layers of the target CT image corresponding to thePET image to be corrected, and is used for attenuation correction of the PET image to be corrected.

Systems and methods for attenuation correction are disclosed. The system includes a coil module (430, 600, 800), which includes a flexible coil (510, 610, 810) and a supporter (520, 620, 820). The supporter (520, 620, 820) may be configured to hold the flexible coil (510, 610, 810). The flexible coil (510, 610, 810) may be deformed to form a receiving space.