Siemens Medical Solutions Usa, Inc.

Sharon Xiaorong Wang

James Frank Caruba

Ronald E Malmin

Joseph Y Fang

James T Chapman

John Thomas Pawlak

Ansgar Graw

Douglas Jay Wagenaar

Trudy Dayle Rempel

Fred E Macciocchi

Govind Pai

Anthony P DelMedico

A system and tuning method to collaboratively calibrate high voltage DAC values and Photomultiplier Tube DAC values of photomultiplier tubes of a gamma camera so that the detector produces a valid energy spectrum over the entire detector surface. A method for tuning a gamma camera having a plurality of photosensors, exposes the photosensors to scintillation photons corresponding to nuclear radiation of known energy; measures an energy output corresponding to each specific photosensor; calculates an average enemy output of all photosensors in the camera; collaboratively adjusts a DAC value corresponding to a voltage applied to a specific photosensor and a DACvalue corresponding to a high voltage applied to the camera based on the calculated average energy, energy output of each photosensor, and a target energy value corresponding to said known energy; and repeats the calibration until convergence is achieved between the average energy, energy output, and target energy.

Method for collaborative tuning of gamma camera

A method for optimizing the scanning trajectory of a radiation detector device, e.g., a SPECT scanning device, about an object generally includes: obtaining object image data using a different imaging modality, e.g., a CT scanning device, determining a maximum object boundary based on the image data, calculating an optimal scan trajectory of the SPECT scanning device relative to the object based on the maximum object boundary, scanning the object with the SPECT scanning device along the optimal scan trajectory to detect gamma photons emanating from the object, from which an image can be reconstructed from the detected gamma photons. Preferably, the SPECT device includes at least two detectors arranged at a pre-selected angle relative to one another and the optimal scan trajectory minimizes the distance between the detectors and the object while maximizing the geometric efficiency of the detectors relative to the object.

Method for generation of SPECT trajectory data from CT data

A medical imaging system having a patient support apparatus is provided. The medical imaging system includes a framework portion and a kit of rigid modular patient support panels, constructed of material having a radiation attenuation coefficient less than that of metals. The panels in sub-combination are removably mounted to and supported by the framework portion. The panels are selectively assembled to define varying surface profiles, including selective gaps there between, that are capable of conforming a patient in contact with the surface profile in a range of supported body positions from supine to seated.

System and method for supporting a patient during medical imaging

A multiple point source test phantom is used for calibration of detector positioning of a nuclear medical imaging apparatus. An absolute coordinate system for the detectors is aligned to an image reconstruction space coordinate system by fitting a Gaussian surface to a peak of a center point source of said test phantom, and using displacement parameters as obtained from the fitted Gaussian surface to calculate a displacement correction parameter, which is used to move a patient bed of the imaging apparatus such that the image reconstruction space is aligned with the absolute coordinate system.

Detector head position calibration and correction for SPECT imaging apparatus using virtual CT

A method and apparatus for acquiring total uniformity for a scintillation imaging apparatus are provided. A generic energy (Z) map is first obtained. The generic Zmap is then corrected for linearity by use of a dot pattern. The listmode data is used to construct an energy histogram matrix. A twin Zmap is then obtained by optimizing the lower and upper boundaries of the energy window for each pixel in relation to the average energy over the Center Field of View.

Non-uniformity energy correction method and apparatus

A method and system for calibrating a scintillation camera includes steps of constructing a pair of generic linearity coefficient (LC) matrices from a representative detector based on measurement of non-linearity; and transforming the pair of generic LC matrices according to measured pinhole locations from a lead mask to generate detector specific LC matrices.

Systems and methods for camera calibration

A system and method provide for more accurate SPECT/CT image registration. CT data is utilized to establish a global spatial coordinate system of a common test phantom. The common test phantom is then used to obtain a set of point source nuclear images. Three-dimensional CT point source data is mapped to a two-dimensional image plane of corresponding point source data, to obtain a pair of intersecting projection cones that are used to obtain a set of detector head position correction parameters to correct detector head positioning in the CT coordinate system when obtaining SPECT projection images of the same object.

Detector head position correction for hybrid SPECT/CT imaging apparatus

A method for reducing the scanning time of SPECT broadly includes determining a physical characteristic of an object within a radiation field, calculating an optimal starting angle of at least two detectors based on the physical characteristic of the object and a trajectory of the at least two detectors such that the geometric efficiency of the detectors along the trajectory can be maximized, angularly displacing the detectors based on the calculated optimal starting angle, scanning the object within the field to detect one or more gamma photons emanating from the object, and preparing an image from the one or more detected gamma photons. Preferably, the physical characteristic of the object is its location within the field, but can include properties such as signal to noise ratio, shape of the object, etc.

Method for reducing nuclear medicine scanning time

In some preferred embodiments, an apparatus is provided that facilitates correction, such as, e.g., linearity correction, in imaging devices, such as, e.g., scintillation cameras. In preferred embodiments, a mask is implemented that can produce images for locating the actual position of a nuclear event based on its apparent position with high accuracy and reliability. In the preferred embodiments, the mask includes a non-uniform array of apertures that can achieve this goal.

Imaging devices and methods employing masks with a non-uniform grid of pinhole apertures

Point source responses of pinhole apertures in a non-uniform grid mask used to spatially calibrate a gamma camera can be modeled as a two-dimensional Gaussian model function. Pinhole data from each pinhole location are added together to generate a complete Gaussian model of the flood image from the mask. The Gaussian model then is subjected to global and PMT-based pattern matching with an actual input flood image obtained using the mask, to obtain a transformed Gaussian model that is more accurately aligned with actual pinhole locations of the mask. The transformed Gaussian model then can be used in a peak detection process for calibration images, which are used to develop LC coefficients for the camera.

PMT-based pattern matching calibration for gamma camera using non-uniform pinhole aperture grid mask

Point source responses of pinhole apertures in a non-uniform grid mask used to spatially calibrate a gamma camera can be modeled as a two-dimensional Gaussian function with a set of seven parameters. The Gaussian parameters can be measured using a surface-fitting algorithm that seeks minimum error in the least squares sense. The process is repeated for data from each pinhole location and the data are added together to generate a complete model of the flood image from the mask, which then can be used in a peak detection process for clinical images.

Peak detection calibration for gamma camera using non-uniform pinhole aperture grid mask

According to some embodiments, a multimodality diagnostic imaging system having one or more gamma cameras and a flat panel x-ray detector mounted on a common gantry to perform simultaneous FPCT and SPECT studies. In other embodiments, such systems may included EKG devices to gate said studies.

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Hoffman Estates, IL, United States of America

Sharon Xiaorong Wang