摘要:
A representative positron emission tomography (PET) calibration system includes a PET scanner having a ring detector, a phantom that is placed at approximately the center of the ring detector, and a time alignment calibration manager that is coupled to the PET scanner. The time alignment calibration manager detects coincidence events from the phantom, calculates position of time of flight events from the ring detector based on the detected coincidence events, and calculates time offsets for the ring detector using a mean value calculation based on the calculated position of the time of flight events.
摘要:
A representative positron emission tomography (PET) calibration system includes a PET scanner having a ring detector, a phantom that is placed at approximately the center of the ring detector, and a time alignment calibration manager that is coupled to the PET scanner. The time alignment calibration manager detects coincidence events from the phantom, calculates position of time of flight events from the ring detector based on the detected coincidence events, and calculates time offsets for the ring detector using a mean value calculation based on the calculated position of the time of flight events.
摘要:
A method for determining quality of sinograms produced by a medical imaging device. The method may include placing a uniform phantom object in the field of view of the medical imaging device; acquiring one or more phantom sinograms of the uniform phantom object; establish a set of parameters for the acquired one or more phantom sinograms; and determine, based on pre-set ranges of the parameters, the quality of sinograms produced by the medical imaging device. The parameters may be one or more parameters of a group of parameters consisting of block uniformity, block efficiency, randoms rate, scanner efficiency, and scatter ratio.
摘要:
A calibration system for a combined Positron Emission Tomography (PET)/Computed Tomography scanner system, may have a support structure carrying a rotation motor driving a phantom, wherein the phantom has at least two phantom rods and the rods are positioned such that they are neither parallel nor connected to each other.
摘要:
The present invention provides a method for estimating crystal efficiency in a PET detector that takes axial compression into account. It does so via an iterative methodology in which a μ-map is first generated and then is used to obtain a solution for the equation L ( ɛ i ) = ∑ n ∈ N y n log ∑ i , j ∈ span g ij ɛ i ɛ j x ij - ∑ i , j ∈ span g ij ɛ i ɛ j x ij , wherein gij is a geometric factor for LOR(i,j), εi and εj are the efficiencies for crystal i and crystal j, and xij is the line integral of the source distribution along LOR(i,j). Once efficiencies are determined, they are used to calibrate the PET detector.
摘要翻译:本发明提供了在考虑轴向压缩的PET检测器中估计晶体效率的方法。 它通过迭代方法来实现,其中首先生成μ映射,然后用于获得等式的解。(∈i)=Σn∈Nn n nΣΣΣ,∈∈∈ 其中gij是LOR(i,j),&egr的几何因子,其中gij是LOR(i,j)的几何因子,eij; i和&egr; j是晶体i和晶体j的效率,xij是沿LOR(i,j)的源分布的线积分。 一旦确定效率,它们被用于校准PET检测器。
摘要:
A normalization apparatus and method for a PET scanner with panel detectors for obtaining an estimate of a normalization array, for correction for count rate effects on the normalization array, and for measurement of the relation between the normalization array and the count rate. The method of the present invention is based on two quasi-independent radial and axial components, which are count rate dependent due to sensitivity changes across the detector blocks. A scatter source is disposed at the center of the FOV and a scatter-free source is disposed at the outer edge of the FOV. The method computes the normalization array through several steps which evaluate the geometric profile, the axial profile, and the correction factor. A count rate correction is introduced to extend the normalization array to any count rate.
摘要:
A method for determining quality of sinograms produced by a medical imaging device. The method may include placing a uniform phantom object in the field of view of the medical imaging device; acquiring one or more phantom sinograms of the uniform phantom object; establish a set of parameters for the acquired one or more phantom sinograms; and determine, based on pre-set ranges of the parameters, the quality of sinograms produced by the medical imaging device. The parameters may be one or more parameters of a group of parameters consisting of block uniformity, block efficiency, randoms rate, scanner efficiency, and scatter ratio.
摘要:
The present invention provides a method for estimating crystal efficiency in a PET detector that takes axial compression into account. It does so via an iterative methodology in which a μ-map is first generated and then is used to obtain a solution for the equation L ( ɛ i ) = ∑ n ∈ N y n log ∑ i , j ∈ span g ij ɛ i ɛ j x ij - ∑ i , j ∈ span g ij ɛ i ɛ j x ij , wherein gij is a geometric factor for LOR(i,j), εi and εj are the efficiencies for crystal i and crystal j, and xij is the line integral of the source distribution along LOR(i,j). Once efficiencies are determined, they are used to calibrate the PET detector.
摘要:
A calibration system for a combined Positron Emission Tomography (PET)/Computed Tomography scanner system, may have a support structure carrying a rotation motor driving a phantom, wherein the phantom has at least two phantom rods and the rods are positioned such that they are neither parallel nor connected to each other.
摘要:
A system and method for reconstructing single photon emission computed tomography data acquired with a pinhole collimator includes sub-dividing each voxel in the imaging target object space into sub-voxels and sub-dividing each of the detector bins in the gamma camera detector into sub-bins, connecting the centers of each of the sub-voxels to each of the detector sub-bins through a pinhole provided in the pinhole collimator by ray tracing and for each ray connecting the centers of each of the sub-voxels to each of the detector sub-bins, the transmission probability is calculated by analytically solving the intersections between the ray and the pinhole surfaces. Then, a geometric-response-function of the pinhole collimator is computed which is then convolved with the intrinsic-response-function of the detector to obtain the PSF.