Analogic Corporation

Doug Q Abraham

Basak Ulker Karbeyaz

David Rozas

Anton M Deykoon

Olivier Tousignant

Carl DeVincent

Lane Howitt

Mitchell Surowiec

Among other things, one or more techniques and/or systems are described for defining imaging modes and for operating a photon counting radiation imaging system. A set of imaging modes with different counting schemes may be defined such that counting schemes will count detection events of a set of radiation events in different manners. For example, a first counting scheme may count primary detection events in a primary counter and secondary detection events in a secondary counter. A second counting scheme may count primary and secondary detection events in the primary counter. A third counting scheme may merely count detection events occurring within a primary detector cell associated with the primary counter. A fourth counting scheme may combine energy of detection events into merged energy. A selected imaging mode may be applied to the photon counting radiation imaging system in order to achieve desired image scanning characteristics (e.g., spatial resolution, dose savings, spectral ability).

Photon counting imaging modes

One or more techniques and/or systems are described for addressing (e.g., during calibration) pixel-by-pixel variations in an image modality that utilizes photon counting techniques, such as by adjusting a number of photons detected by certain pixels (e.g., redistributing or reallocating detected photons among pixels). Such variations may cause an effective area of one or more pixels of a detector array to be larger than the effective area of other pixels, resulting in more photons being counted by some pixels than others, which can degrade resulting images. Accordingly, photons are redistributed as provided herein so that, when exposed to substantially uniform radiation, photon counts of neighboring pixels are substantially equal, statistical noise among neighboring pixels is substantially equal, and a signal-to-noise ratio among neighboring pixels is substantially equal. By redistributing photons as described herein, a spatial uniformity and/or a modulated transfer function (MTF) associated with a detector array may be improved.

Photon count correction

A resonant power converter. An embodiment with a fullbridge converter is disclosed, controlled with feedback or feedforward technique. Switching schemes are either based on a sort of look up table or on measurement of current or voltage. Dead time may be adjusted. Timing may be such, that in the respective diagonal pairs of the converter, one switch is switched on for a different time (different pulse width) than the other. Use in a relative high power environment for about 20 KW in e.g. an X-Ray or Computer Tompgrapy System.

Wide power range resonant converter

Among other things, one or more techniques and/or systems for counting detection events via a photon counting detector array is provided. A first instance where an amplitude of an electrical signal exceeds an event threshold is detected. The first instance is generated responsive to a first detection event at a detector cell. An event counter is disabled from counting other detection events at the detector cell for a first blocking interval. At a conclusion of the first blocking interval, the amplitude of the electrical signal is determined. Responsive to determining that the amplitude of the electrical signal is below the event threshold, an adjustment is made to an event count based upon the first detection event. Responsive to determining that the amplitude of the electrical signal exceeds the event threshold, the event counter is disabled from counting other detection events at the detector cell for a second blocking interval.

Photon counting system and method

Among other things, one or more systems and/or techniques are described for dynamically adjusting, in a fan-angle direction, attenuation of radiation during an examination of an object such that portions of the object that are not represented in resulting (tilted/targeted) images of the object are exposed to less radiation than portions of the object that are represented in resulting (tilted/targeted) images of the object. As a rotating gantry is rotated, blades of a pre-object collimator are dynamically repositioned to selectively attenuate emitted radiation. A collimator adjustment component may be configured to determine how to reposition the blades based at least in part upon at least one of a desired tilt of the resulting (tilted) image(s), a translational position of the object, and a gantry rotation angle, for example.

Dose reduction via dynamic collimation adjustment for targeted field of view and/or digital tilt CT

The techniques described herein provide for correcting for pulse pile-up and/or charge sharing in a radiation scanner (). It finds particular application with the use of a pixilated radiation detector () (e.g., a photon counting detector). A circuit (), comprising a plurality of comparators (), is configured to determine the energy spectrum of a pulse produced from a photon strike. If the energy spectrum is greater than the energy range for a pulse produced by a single photon strike given an input spectrum and/or if pulses produced from adjacent pixels have temporal coincidence, pulse pile-up and/or charge sharing may be identified and a correction mechanism/correction factors may be applied to determine an actual number of photons that struck the detector ().

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Topsfield, MA, United States of America

Doug Q Abraham