119 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.

Embodiments of the present invention provide a computer program, method, and system to facilitate hybrid CT attenuation correction. In one embodiment, the method generally includes acquiring data from a scanner, utilizing an ordered subset expectation maximization-bayesian algorithm to reconstruct the acquired data, and forward projecting the reconstructed data. Such a configuration minimizes the computing resources required for reconstruction and improves attenuation correction accuracy.

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 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; anda 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 method for generating a positron emission tomography (PET) attenuation correction map from magnetic resonance (MR) images includes segmenting a 3-dimensional (3D) magnetic resonance (MR) whole-body image of a patient into low-signal regions, fat regions, and soft tissue regions; classifying the low-signal regions as either lungs, bones, or air by identifying lungs, identifying an abdominal station, and identifying a lower body station; and generating an attenuation map from the segmentation result by replacing the segmentation labels with corresponding representative attenuation coefficients.

A method of analyzing an ultrasound image of a target volume having therein at least two types of substances is disclosed. The method comprises: dividing a region-of-interest of the image to a set of mini-segments. The method further comprises, for each mini-segment, calculating at least two representative intensity values, respectively representing the at least two types of substances. The method further comprises applying attenuation corrections to each representative intensity value of at least a subset of the set of mini-segments, so as to map the region-of-interest according to the at least two types of substances.

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.