摘要:
A transmission pre-scan of a patient is used in a nuclear medicine imaging system to determine the duration of a subsequent transmission scan of the patient. The transmission scan is for acquiring an attenuation map of the patient to correct emission data of the patient for non-uniform attenuation. As a result, the patient's exposure to radiation during the transmission scan is not excessive, yet transmission image quality is maintained. A radiation transmission source and a radiation detector are operated to perform the transmission pre-scan of the object, during which the transmission source remains in a fixed position. Downscatter correction is applied to correct the transmission pre-scan data for emission contamination. Count values from the pre-scan data are integrated axially. A water-equivalent cross-section value of the patient is then determined based on data acquired from the transmission pre-scan, and the duration of the transmission scan is computed based on the water-equivalent cross-section value.
摘要:
A physiological parameter monitor (44) monitors a cyclic physiological parameter and generates a cyclic parameter phase indicative signal. A radiation system (8) is disposed adjacent an examination region (18, 28) to generate transmission radiation data and emission radiation data. First and second sorting devices (48, 74) sort corresponding transmission and emission radiation data into transmission radiation data sets (50) and emission radiation data sets (78) corresponding to each of a plurality of the cyclic parameter phases. A data processor (60) reconstructs attenuation maps (62) from the transmission data for each of the plurality of cyclic parameter phases. An image processor (80) corrects the emission radiation data of each cyclic parameter phase with the attenuation map (62) of the same cyclic parameter phase and reconstructs the attenuation corrected emission data sets into an image representation for each cyclic parameter phase.
摘要:
A method for non-rigid registration and fusion of images with physiological modeled organ motions resulting from respiratory motion and cardiac motion that are mathematically modeled with physiological constraints. A method of combining images comprises the steps of obtaining a first image dataset (24) of a region of interest of a subject and obtaining a second image dataset (34) of the region of interest of the subject. Next, a general model of physiological motion for the region of interest is provided (142). The general model of physiological motion is adapted with data derived from the first image data set (140) to provide a subject specific physiological model (154). The subject specific physiological model is applied (172) to the second image dataset (150) to provide a combined image (122).
摘要:
A physiological parameter monitor (44) monitors a cyclic physiological parameter and generates a cyclic parameter phase indicative signal. A radiation system (8) is disposed adjacent an examination region (18, 28) to generate transmission radiation data and emission radiation data. First and second sorting devices (48, 74) sort corresponding transmission and emission radiation data into transmission radiation data sets (50) and emission radiation data sets (78) corresponding to each of a plurality of the cyclic parameter phases. A data processor (60) reconstructs attenuation maps (62) from the transmission data for each of the plurality of cyclic parameter phases. An image processor (80) corrects the emission radiation data of each cyclic parameter phase with the attenuation map (62) of the same cyclic parameter phase and reconstructs the attenuation corrected emission data sets into an image representation for each cyclic parameter phase.
摘要:
In an imaging method, estimated data is iteratively projected and backprojected. The iterative projecting and backprojecting includes projecting or backprojecting the estimated data along parallel paths each employing energy-dependent parameters appropriate for a different energy. During each iteration, the estimated data is adjusted based on comparison of the estimated data with measured data.
摘要:
A medical imaging system (10) includes at least one radiation detection head (16) disposed adjacent a subject receiving aperture (18) to detect radiation from a subject. The detected radiation is reconstructed into at least one initial 2D projection image (μ). Resolution in each initial 2D image (μ) is restored by using the extended iterative constrained deconvolution algorithm by incorporating different estimates of the system response function which estimates correspond to different distances between the detection head and the origins of the detected radiation. Measured response functions are used to restore a series of images. The optimal image is determined by automatic searching with the figure of merit, by user's observation, or by using blind deconvolution for a concurrent estimating of the system response function and updating the original image.
摘要:
An imaging system (10) comprises at least one radiation detector (20) disposed adjacent a subject receiving aperture (18) to detect radiation from a subject, receive the radiation and generate measured data. An image processor (38) iteratively reconstructs the detected radiation into image representations, in each reconstruction iteration the image processor (38) applies noise reduction algorithms to at least a difference between the measured data and a portion of a previous iteration image representation.
摘要:
A gamma camera system and method are described which use multiple point sources to detect inaccuracies in detector translational and rotational alignment. In practice of the method of the preferred embodiment, three capillary tubes, each containing a drop of an isotope, are located in different planes and locations with respect to the axis of rotation of the detectors. A SPECT acquisition is performed and the point source projection data is processed to calculate the point source coordinates, from which center-of-rotation correction factors may be calculated. These correction factors are applied by mechanical and software adjustments to the gantry and acquisition systems of the camera to correct for both translational and rotational inaccuracies.
摘要:
An anatomical image data set and an emission image data set are acquired for a subject. An attenuation map is generated from the anatomical image data set. The emission image data set is reconstructed to generate an emission image. The reconstructing includes correcting for attenuation of emission radiation in the subject using the attenuation map. A value is calculated for a quality assurance (QA) metric quantifying alignment of the attenuation map with the emission image. The emission image is displayed or printed together with the calculated quality assurance metric. In some embodiments, prior to the reconstructing the attenuation map is registered with the emission image data set by performing a global rigid registration followed by a local non-rigid registration of a region of interest.
摘要:
An anatomical image data set and an emission image data set are acquired for a subject. An attenuation map is generated from the anatomical image data set. The emission image data set is reconstructed to generate an emission image. The reconstructing includes correcting for attenuation of emission radiation in the subject using the attenuation map. A value is calculated for a quality assurance (QA) metric quantifying alignment of the attenuation map with the emission image. The emission image is displayed or printed together with the calculated quality assurance metric. In some embodiments, prior to the reconstructing the attenuation map is registered with the emission image data set by performing a global rigid registration followed by a local non-rigid registration of a region of interest.