Johns Hopkins University

Katsuyuki Taguchi

Hiroyuki Kudo

Somesh Srivastava

Kenji Amaya

Kento Nakada

Techniques for counting respective photons having energy levels within at least a first energy window and a second energy window, where the first energy window is lower than the second energy window, are presented. The techniques include: receiving a first indication of a first photon detection, the first photon detection being of a photon having an energy of at least a lower end of the first energy window; receiving a second indication of a second photon detection, the second photon detection being of a photon having an energy of at least a lower end of the second energy window; within a predetermined time interval of the receiving the first indication, communicating locally the second indication to counter logic for the first energy window, where a counter for the first energy window is not incremented; and incrementing a counter for an energy window higher than the first energy window.

Direct energy windowing for photon counting detectors

A method, a system, a device, and a computer program produce for photon detection is disclosed. The method includes receiving, by a plurality of anodes, a photon via one or more of the plurality of anodes; measuring respective voltages of the photon at each of the plurality of anodes; counting incidents in which the photon is detected by more than one of the plurality of anodes based on the measuring; and outputting information regarding a counted number of incidents in which the photon is detected by more than one of the plurality of anodes, wherein the information regarding the courted number of incidents in which the photon is detected by more than one of the plurality of anodes is used as part of a production of an image associated with the received photon.

Photon counting detector

The present invention is directed to a new joint estimation framework employing MAP estimation based on pixel-based latent variables for tissue types. The method combines the geometrical information described by latent MRF, statistical relation between tissue types and P-C coefficients, and Poisson noise models of PCD data, and makes possible the continuous Baysian estimation from detected photon counts. The proposed method has better accuracy and RMSE than the method using FBP and thresholding. The joint estimation framework has the potential to further improve the accuracy by introducing more information about tissues in human body, e.g., the location, size, and number of tissues, or limited variation of neighboring tissues, which will be easily formulated by pixel-based latent variables.

Joint estimation of tissue types and linear attenuation coefficients for computed tomography

An embodiment in accordance with the present invention provides a new SR compensation (SRC) method, using a more efficient conjugate gradient method. In this method, the first and second derivatives are directly calculated analytically. The proposed SRC uses a sinogram restoration approach, integrates the SRF as a part of a forward imaging model, and compensates for the effect of the SR by maximizing the Poisson log-likelihood of measurements. The algorithm can be evaluated using as a simulated fan-beam x-ray CT scanner.

Spectral response effects (SRE) compensation method for photon counting detectors (PCDs)

Featured are methods for reconstruction of images acquired from any of a number of scanning devices or apparatuses known to those skilled in the art which methods are established so as to provide a mechanism for compensating for motion of an object being imaged. Such methods of the present invention are such as to allow the clinician to select one or more specific methodologies that is appropriate for the expected motion, severity or complexity of the motion and efficient processing of projection data. Also feature are systems, apparatuses, software code and computer readable media which embody such methodologies.

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Elkridge, MD, United States of America

Katsuyuki Taguchi