Siemens Medical Solutions Usa, Inc.

Siemens Medical Systems, Inc.

Siemens Gammasonics, Inc.

Ronald E Malmin

James Frank Caruba

Sharon Xiaorong Wang

James T Chapman

Xinhong Ding

Alexander Hans Vija

Miesher Rodrigues

Roger E Arseneau

Francesc dAssis Massanes Basi

Joseph Y Fang

Trudy Dayle Rempel

Manjit Ray

Fred E Macciocchi

William R Guth

Anthony P DelMedico

Amos Yahill

To capture more emitted photons with a Compton camera, the scatter detector is tilted (non-orthogonal angle) relative to a radial from the isocenter of the imaging system. The tilt creates a greater volume for scatter interaction. To capture more scatter photons, the catcher detector is non-planar, such as a multi-faced detector at least partially surrounding a volume behind the scatter detector. The tilted scatter detector alone, the non-planar catcher detector alone, or the tilted scatter detector and the non-planar catcher detector are used in the Compton camera.

Near 2Pi Compton camera for medical imaging

A framework for characterization of a collimator. In accordance with one aspect, first and second sides of the collimator are photographed to generate first and second image data. An optical characterization map (OCM) may be generated based on the first and second image data, wherein the optical characterization map characterizes the individual channels of the collimator. Quality assessment or image reconstruction may then be performed based on the OCM.

Individual channel characterization of collimator

A system and method includes acquisition of a plurality of images depicting a respective scintillator crystal, determination of a plurality of categories based on the plurality of images, determination of a crystal quality value associated with each of the plurality of categories, training of a network to receive an input image and output an indication of one of the plurality of categories based on the input image, the training based on the plurality of images and the at least one category associated with each pf the plurality of images, operation of the trained network to receive a first image of a first scintillator crystal and output a first one of the plurality of categories based on the first image, and determination of a quality of the first scintillator crystal based on the first one of the plurality of categories and a first crystal quality value associated with the first one of the plurality of categories.

Scintillator crystal evaluation system

A system includes reception of an a electrical signal from a light sensor, determination of a first integral over a first number of samples of the electrical signal, determination of an estimated energy of a first pulse based on the first integral, where the electrical signal includes the first pulse and a second pulse, where a portion of the second pulse overlaps a portion of the first pulse, determination of a second integral over a second number of samples of the electrical signal, determination of a second estimated energy of the first pulse over the second number of samples, determination of a residual short integral based on the second integral and the second estimated energy, and determination of an estimated energy of the second pulse based on the residual short integral.

System and method to unpile overlapping pulses

For count loss correction, the capability of the discriminator, measured periodically, to detect an event is identified. Rather than inserting an actual event or a signal emulating an actual event for discrimination, the capability to discriminate is tested by a virtual injection. The count loss may be directly measured without causing extra actual discrimination by the discriminator. Direct measurement with virtual testing may avoid loss of accuracy due to time and use-case variation.

Gamma system count loss correction with virtual pulse injection

Disclosed herein is a method for estimating count loss in a gamma camera comprising injecting a synthetic pulse at a given rate into a data stream emanating from a photo detector; integrating the synthetic pulse into the data stream to form an integrated data stream; determining a number of synthetic pulses from the data stream that pass onto a final image; and determining the count loss from the Equation (2) 

Method for dead time determination in a gamma camera and a system for accomplishing the same

Disclosed herein is a method for removing septal shadows from thick septa collimator images, comprising disposing a line radiation source in a first orientation with respect to an imaging detector; disposing a thick septa collimator between the line radiation source and the imaging detector; where the collimator and the detector move in unison with one another; obtaining a plurality of a line images, where each line image is taken at a different location of the line radiation source with respect to the thick septa collimator; wherein each different location of the line radiation source is along a first linear direction; and relocating the plurality of the line images so obtained to a common location; and summing the images to reduce the septal shadow effects.

Method of reduction of septal shadows for thick septa collimators

A photon collimator, suitable for use in medical imaging equipment, is constructed from a block of photon-attenuating material, such as solid tungsten or molybdenum alloy that defines a plurality of integrally formed septa slats. Each slat has an elongated length dimension greater than thickness and depth dimensions, and is oriented in an opposed pattern array that is laterally spaced relative to its respective thickness dimension. An aperture channel is defined between each pair of opposed slats. Rows of integrally formed slats in one block or separately affixed blocks may be stacked on each other at skewed angles to form two-dimensional grids of apertures having polygonal cross sections. The slats may be formed by electric discharge or laser thermal ablation machining, such as by a sequential passing of an EDM wire cutting head along the pattern array, repeating sequential cutting of respective channel depth and width.

Method for fabricating medical imaging multilayer, multiaperture collimator

Multilayer, multiaperture collimator for medical imaging and fabrication method

A method for performing reconstruction of single photon emission computed tomographic images wherein forward and/or backward projection steps in the reconstruction utilize measured collimator hole orientation angles, whereby the reconstructed tomographic images have improved image resolution and reduced distortion and artifact content.

System and method for measuring hole orientation for SPECT collimators

In an imaging system employing a multifocal collimator, displaying an image. Framing an event stream into a first buffer. Mapping each first buffer bin to a bin of each of a normalization buffer and a count buffer. Normalization buffer and count buffer are the same dimension. First buffer bins correspond to normalization buffer bins and the count buffer bins such that geometric distortion from the multifocal collimator is substantially reduced. The value of each normalization buffer bin corresponds to the quantity of corresponding first buffer bins corresponding to that normalization buffer bin, and a value of each count buffer bin corresponds to total counts of the one or more of the first buffer bins corresponding to the each count buffer bin. Determining an updated image as the ratio of the values of count buffer bins to the normalization buffer bins. Displaying an image as a function of the updated image.

Image production in imaging systems employing a multifocal collimator

A method for measuring a SPECT collimator's hole orientation angles includes (a) providing a plurality of parallel spaced apart line radiation sources at a distance from a detector; (b) positioning a first collimator between the plurality of spaced apart line radiation sources and the detector; (c) obtaining a set of line images of the plurality of line radiation sources by scanning/stepping the plurality of line radiation sources across the first collimator in a first direction; (d) obtaining a second set of line images of the plurality of line radiation sources by scanning/stepping the plurality of line radiation sources across the first collimator in a second direction thai is perpendicular to the first direction; (c) repeating the steps (c) and (d) for a second collimator, wherein one of the two collimators is a reference collimator and the other of the two collimators is a collimator being measured.

A method for measuring a SPECT collimator's hole orientation angles includes obtaining a set of stepped radiation line images of a line radiation source by scanning/stepping the line radiation source across a first collimator in a first direction; obtaining a second set of stepped radiation line images of the line radiation source across the first collimator in a second direction that is perpendicular to the first direction; and obtaining two sets of stepped radiation line images for a second collimator, wherein one of the two collimators is a reference collimator and the other is a collimator being measured. Calculating the collimator hole orientation angles requires determining offset distances along the two directions for each pair of lines between the reference collimator's line images and the measured collimator's line images by identifying and pairing the lines from the reference collimator line images and the measured collimator line images. The method provides an automated way of identifying and pairing the lines.

Automatic line identification and pairing for nuclear imaging collimator vector map characterization

A method of tuning an imaging system can include the steps of receiving photons at photo-multiplier units that are part of an array, determining an energy level for each of the photo-multiplier units based on events over a specific photo-multiplier unit and determining a sum energy level for the array of photo-multiplier units based on the events over the specific photo-multiplier unit. The method can also include the step of comparing the energy level for each of the photo-multiplier units with the sum energy level for the array of photo-multiplier units to assist in determining a contribution matrix for the array of photo-multiplier units. The energy level determination steps and the comparison step can be repeated for each photo-multiplier unit in the array to determine the contribution matrix.

Imaging system and method for tuning same

An improved system and method for tuning individual sensors (e.g., photomultiplier tubes) of a multi-sensor imaging system such as e.g., a gamma camera having an array of photo-multiplier tubes is provided that produces a uniform response over the entire system. Individual sensors of a multi-sensor imaging system are tuned based explicitly or implicitly on gain characteristics of individual sensors of the multi-sensor imaging system so as to produce a uniform response over the system.

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Chicago, IL, United States of America

Ronald E Malmin