University of Arizona

Canon Kabushiki Kaisha

Lars R Furenlid

Xin Li

Harrison H Barrett

Brian Miller

H Bradford Barber

Maria Ruiz-Gonzalez

Akinori Ohkubo

Luca Caucci

The present invention provides a method of calibrating gamma-ray and photon counting detectors, including, but not limited to, monolithic crystal detectors. The method of the present invention is based on the observation that measurement of fan beam datasets allows the synthesis of collimated beam data to derive MDRFs by use of an algorithm that finds the common or intersecting data subsets of two or more orthogonal calibration datasets. This makes the calibration process very efficient while still allowing the full benefits of maximum-likelihood event-parameter estimation that incorporates the statistical nature of the light sensor measurements.

Calibration method and system for photon or particle counting detectors

A scintillation-crystal based gamma-ray detector with photon sensors disposed on edge surface(s) of the crystal to take advantage of total internal reflection of scintillation photons within the thin-slab detector substrate to improve spatial resolution of determination of a scintillation event (including depth-of-interaction resolution) while preserving energy resolution and detection efficiency. The proposed structure benefits from the reduced&#x2014;as compared with related art&#x2014;total number of readout channels elimination of need in complicated and repetitive cutting and polishing operations to form pixelated crystal arrays used in conventional PET detector modules. Detectors systems utilizing stacks of such detectors, and methods of operation of same.

Scintillation detector based systems and methods for using the same

A delta sigma modulator includes a summation circuit, at least one integrator, a multi-bit quantizer and a negative feedback circuit. The summation circuit is configured to produce a difference signal between a unipolar or bipolar analog input signal and an analog feedback signal. The integrator is operatively coupled to the summation circuit to integrate the difference signal. The multi-bit quantizer is operatively coupled to the integrator to digitize the integrated signal to generate an N-bit digital output signal, N being an integer greater than 1. The negative feedback circuit operatively couples the multi-bit quantizer to the summation circuit. The negative feedback circuit includes a digital-to-analog converter arrangement for receiving the N-bit digital output signal and providing the analog feedback signal such that digital values of the N-bit digital output signal and values of the analog feedback encoded by the digital values have a non-linear relationship to one another.

Optimizable analog-to-digital converter for unipolar or bipolar pulse signals based on multi-bit sigma-delta modulation

The invention provides a novel arrangement of photon sensors on a scintillation-crystal based gamma-ray detector that takes advantage of total internal reflection of scintillation light within the scintillation detector substrate. The present invention provides improved spatial resolution including depth-of-interaction (DOI) resolution while preserving energy resolution and detection efficiency, which is especially useful in small-animal or human positron emission tomography (PET) or other techniques that depend on high-energy gamma-ray detection. Moreover, the new geometry helps reduce the total number of readout channels required and eliminates the need to do complicated and repetitive cutting and polishing operations to form pixelated crystal arrays as is the standard in current PET detector modules.

Scintillation detector and associated scintillation detector ring and method

A delta sigma modulator includes a summation circuit, at least one integrator, a multi-bit quantizer and a negative feedback circuit. The summation circuit is configured to produce a difference signal between an analog input signal and an analog feedback signal. The integrator is operatively coupled to the summation circuit to integrate the difference signal. The multi-bit quantizer is operatively coupled to the integrator to digitize the integrated signal to generate an N-bit digital output signal, N being an integer greater than 1. The negative feedback circuit operatively couples the multi-bit quantizer to the summation circuit. The negative feedback circuit includes a digital-to-analog converter arrangement for receiving the N-bit digital output signal and providing the analog feedback signal such that digital values of the N-bit digital output signal and values of the analog feedback encoded by the digital values have a non-linear relationship to one another.

Adaptive analog-to-digital converter for pulsed signals based on multi-bit sigma-delta modulation

A method for forming an optimized image of a subject includes steps of acquiring a plurality of one-dimensional images, generating a measured sinogram from the plurality of one-dimensional images, and determining a plurality of trial images. In the step of acquiring, the method acquires a plurality of one-dimensional images of the subject captured by a rotating-slit imager having (a) a detector, and (b) a slit collimator having a slit oriented at one of a respective plurality of slit-rotation angles, relative to the subject, about a longitudinal axis substantially perpendicular to a front surface of the detector. In the step of determining, the method iteratively determines a plurality of trial images each having a respective trial sinogram. The optimized image is one of the plurality of trial images and its corresponding trial sinogram differs from the measured sinogram by less than a predetermined tolerance.

Rotating-slit gamma-ray imager and associated imaging method

An apparatus for estimating a wavefront parameter includes a light source, a lenslet array, a detector for detecting light generated by the light source and passed through the lenslet array, a wavefront corrective element disposed between the lenslet array and the light source; and a data analyzer configured to estimate at least one wavefront parameter at a plane located on the light source side of the corrective element. The lenslet array and the sensor array are arranged to form a wavefront sensor, and the wavefront corrective element is configured to correct an aberration of the wavefront.

Apparatus and method for estimating wavefront parameters

An X-ray detection device including a scintillator configured to convert gamma rays or X-rays into optical radiation, an optical image intensifier configured to intensify the optical radiation to generate intensified optical radiation, an optical coupling system configured to guide the intensified optical radiation, and a solid state detector configured to detect the intensified optical radiation to generate an interaction image representing an X-ray energy emission and to perform photon counting based on data of the interaction image.

X-ray detector including scintillator, a lens array, and an image intensifier

A gamma-ray or X-ray detection device including a scintillator configured to convert gamma rays or X-rays into optical radiation, an optical image intensifier configured to intensify the optical radiation to generate intensified optical radiation, an optical coupling system configured to guide the intensified optical radiation, and a solid state detector configured to detect the intensified optical radiation to generate an interaction image representing a gamma-ray or X-ray energy emission.

Growing community of inventors

Tucson, AZ, United States of America

Lars R Furenlid