Abstract: The present subject matter relates to systems and methods for temporal multiplexing x-ray imaging of dynamic objects with high temporal resolution and fast imaging speed. A pulsed x-ray beam can irradiate an object undergoing a range of motion such as a cyclic motion. Multiple x-ray images can be acquired at different phases within a single motion cycle or range of the object. The multiple x-ray images can be demultiplexed to produce an individual phase image. Compared to sequential imaging, temporal multiplexing x-ray imaging can achieve high temporal resolution of dynamics object in multiple phases with imaging time comparable to that of a single phase. Temporal multiplexing x-ray imaging can thus be applied to a wide variety of applications, including biomedical imaging and industrial non-destructive testing.

Abstract: The present subject matter relates to systems and methods for temporal multiplexing x-ray imaging of dynamic objects with high temporal resolution and fast imaging speed. A pulsed x-ray beam can irradiate an object undergoing a range of motion such as a cyclic motion. Multiple x-ray images can be acquired at different phases within a single motion cycle or range of the object. The multiple x-ray images can be demultiplexed to produce an individual phase image. Compared to sequential imaging, temporal multiplexing x-ray imaging can achieve high temporal resolution of dynamics object in multiple phases with imaging time comparable to that of a single phase. Temporal multiplexing x-ray imaging can thus be applied to a wide variety of applications, including biomedical imaging and industrial non-destructive testing.

Abstract: Tomography limitations in vivo due to incomplete, inconsistent and intricate measurements require solution of inverse problems. The new strategies disclosed in this application are capable of providing faster data acquisition, higher image quality, lower radiation dose, greater flexibility, and lower system cost. Such benefits can be used to advance research in cardiovascular diseases, regenerative medicine, inflammation, and nanotechnology. The present invention relates to the field of medical imaging. More particularly, embodiments of the invention relate to methods, systems, and devices for imaging, including tomography-based and MRI-based applications. For example, included in embodiments of the invention are compressive sampling based tomosynthesis methods, which have great potential to reduce the overall x-ray radiation dose for a patient.

Abstract: An x-ray imaging system has an x-ray source having an electron field emission source that emits an x-ray beam that strikes an elongated, stationary anode in an evacuated housing. A magnetic deflection system steers the electron beam between the electron field emission source and the anode, so that the electron beam can strike the anode at different locations, thereby causing x-rays to be emitted from those different locations, by controlling the degree of magnetic deflection. A radiation detector detects the x-rays after attenuation by an examination subject, and generates signals dependent on the detected radiation that represent an image of the subject.

Abstract: Methods, systems, and computer program products for binary multiplexing x-ray radiography are disclosed. According to one aspect, the subject matter described herein can include irradiating an object with composite x-ray beams including signals based on a predetermined binary transform. Further, the subject matter described herein can include detecting x-ray intensities associated with the signals of the composite x-ray beams. An inverse binary transform can be applied to the detected x-ray intensities associated with the signals of the composite x-ray beams to recover the signals of the composite x-ray beams.

Abstract: Micro-focus field emission x-ray sources and related methods are provided. A micro-focus field emission x-ray source can include a field emission cathode including a film with a layer of electron field emitting materials patterned on a conducting surface. Further, the x-ray source can include a gate electrode for extracting field emitted electrons from the cathode when a bias electrical field is applied between the gate electrode and the cathode. The x-ray source can also include an anode. Further, the x-ray source can include an electrostatic focusing unit between the gate electrode and anode. The electrostatic focusing unit can include multiple focusing electrodes that are electrically separated from each other. Each of the electrodes can have an independently adjustable electrical potential. A controller can be configured to adjust at least one of the electrical potentials of the focusing electrodes and to adjust a size of the cathode.

Abstract: A method for depositing a coating of a nanostructure material onto a substrate includes: (1) forming a solution or suspension of containing the nanostructure material; (2) selectively adding “chargers” to the solution; (3) immersing electrodes in the solution, the substrate upon which the nanostructure material is to be deposited acting as one of the electrodes; (4) applying a direct and/or alternating current electrical field between the two electrodes for a certain period of time thereby causing the nanostructure materials in the solution to migrate toward and attach themselves to the substrate electrode; and (5) subsequent optional processing of the coated substrate.

Abstract: Systems and methods for x-ray imaging and scanning of objects are disclosed. According to one aspect, the subject matter described herein can include providing an x-ray source configured to generate a plurality of individually-controllable x-ray beams, positioning an object to be imaged in a path for intercepting at least one of the x-ray beams, activating the x-ray source, detecting intensities of the emitted x-ray beams, and generating imaging data based on the intensities for constructing an image of the object.

Abstract: Multi-pixel electron microbeam irradiator systems and methods are provided with particular applicability for selectively irradiating predetermined cells or cell locations. A multi-pixel electron microbeam irradiator system can include a plurality of individually addressable electron field emitters sealed in a vacuum. The multi-pixel electron microbeam irradiator system can include an anode comprising one or more electron permeable portions corresponding to the plurality of electron field emitters. Further, the multi-pixel electron microbeam irradiator system can include a controller operable to individually control electron extraction from each of the electron field emitters for selectively irradiating predetermined locations such as cells or cell locations.

Abstract: X-ray imaging systems and methods are provided that use temporal digital signal processing for reducing noise and for obtaining multiple images simultaneously. An x-ray imaging system can include an x-ray source adapted to generate a pulsed x-ray beam having a predetermined frequency and apply the pulsed x-ray beam to an object to be imaged. An x-ray detector can be adapted to detect x-ray radiation from the object and generate temporal data based on the x-ray radiation. A temporal data analyzer can be adapted to apply a temporal signal process to the temporal data to remove at least a portion of the temporal data having a different frequency than the predetermined frequency.

Abstract: Methods and systems are provided for attaching one or magnetic nanowires to an object and apparatuses formed therefrom. An electrophoresis method for attaching one or more nanowires to a sharp tip of an object can include including providing one or more magnetic nanowires in a liquid medium. The method can also include positioning a sharp tip of an object in the liquid medium. Further, the method can include applying an electrical field to the liquid medium for attaching the one or more magnetic nanowires to the sharp tip.

Abstract: Computed tomography device comprising an x-ray source and an x-ray detecting unit. The x-ray source comprises a cathode with a plurality of individually programmable electron emitting units that each emit an electron upon an application of an electric field, an anode target that emits an x-ray upon impact by the emitted electron, and a collimator. Each electron emitting unit includes an electron field emitting material. The electron field emitting material includes a nanostructured material or a plurality of nanotubes or a plurality of nanowires. Computed tomography methods are also provided.

Abstract: A method for depositing a nanostructure-containing material onto an object or substrate includes one or more of the following: (1) forming a solution or suspension of nanostructure-containing material, (2) selectively adding “chargers” to the solution, (3) immersing electrodes in the solution, the substrate or object upon which the nanostructure material is to be deposited acting as one of the electrodes, (4) applying a direct and/or alternating current electrical field between the two electrodes for a certain period of time thereby causing the nanostructure materials in the solution to migrate toward and attach themselves to the substrate electrode, and (5) subsequent optional processing of the coated substrate. Associated objects and devices are also provided. A method for separating nanostructures based on their properties and/or geometry is also described.

Abstract: An x-ray generating device includes a field emission cathode formed at least partially from a nanostructure-containing material having an emitted electron current density of at least 4 A/cm2. High energy conversion efficiency and compact design are achieved due to easy focusing of cold cathode emitted electrons and dramatic reduction of heating at the anode. In addition, by pulsing the field between the cathode and the gate or anode and focusing the electron beams at different anode materials, pulsed x-ray radiation with varying energy can be generated from a single device. Methods and apparatus for independent control of electron emission current and x-ray energy in x-ray tubes are also provided. The independent control can be accomplished by adjusting the distance between the cathode and anode. The independent control can also be accomplished by adjusting the temperature of the cathode. The independent control can also be accomplished by optical excitation of the cathode.

Abstract: An x-ray generating device includes a field emission cathode formed at least partially from a nanostructure-containing material having an emitted electron current density of at least 4 A/cm2. High energy conversion efficiency and compact design are achieved due to easy focusing of cold cathode emitted electrons and dramatic reduction of heating at the anode. In addition, by pulsing the field between the cathode and the gate or anode and focusing the electron beams at different anode materials, pulsed x-ray radiation with varying energy can be generated from a single device. Methods and apparatus for independent control of electron emission current and x-ray energy in x-ray tubes are also provided. The independent control can be accomplished by adjusting the distance between the cathode and anode. The independent control can also be accomplished by adjusting the temperature of the cathode. The independent control can also be accomplished by optical excitation of the cathode.

Abstract: Carbon nanotube material having an outer diameter less than 10 nm and a number of walls less than ten are disclosed. Also disclosed are an electron field emission device including a substrate, an optionally layer of adhesion-promoting layer, and a layer of electron field emission material. The electron field emission material includes a carbon nanotube having a number of concentric graphene shells per tube of from two to ten, an outer diameter from 2 to 8 nm, and a nanotube length greater than 0.1 microns. One method to fabricate carbon nanotubes includes the steps of (a) producing a catalyst containing Fe and Mo supported on MgO powder, (b) using a mixture of hydrogen and carbon containing gas as precursors, and (c) heating the catalyst to a temperature above 950° C. to produce a carbon nanotube.

Abstract: A structure to generate x-rays has a plurality of stationary and individually electrically addressable field emissive electron sources with a substrate composed of a field emissive material, such as carbon nanotubes. Electrically switching the field emissive electron sources at a predetermined frequency field emits electrons in a programmable sequence toward an incidence point on a target. The generated x-rays correspond in frequency and in position to that of the field emissive electron source. The large-area target and array or matrix of emitters can image objects from different positions and/or angles without moving the object or the structure and can produce a three dimensional image. The x-ray system is suitable for a variety of applications including industrial inspection/quality control, analytical instrumentation, security systems such as airport security inspection systems, and medical imaging, such as computed tomography.

Abstract: Computed tomography device comprising an x-ray source and an x-ray detecting unit. The x-ray source comprises a cathode with a plurality of individually programmable electron emitting units that each emit an electron upon an application of an electric field, an anode target that emits an x-ray upon impact by the emitted electron, and a collimator. Each electron emitting unit includes an electron field emitting material. The electron field emitting material includes a nanostructured material or a plurality of nanotubes or a plurality of nanowires. Computed tomography methods are also provided.

Abstract: An x-ray generating device includes at least one field-emission cold cathode having a substrate and incorporating nanostructure-containing material including carbon nanotubes. The device further includes at least one anode target. Associated methods are also described.

Abstract: A field emission ion source has nanostructure materials on at least an emitting edge of the anode electrode. Metal is transferred from a metal reservoir to the emitting edge of the anode, where the metal is transferred to an emitting end of the nanostructure materials and is ionized under an applied electric field. Plural ion sources can be combined to form a field emission ion source device. The numbers of emitting sources are selectable through electric or mechanical switches and different ion extraction potentials can be applied. Various nanostructure materials include: single wall carbon nanotubes and bundles, few-walled carbon nanotubes and bundles, multi-walled carbon nanotubes and bundles, and carbon fiber. Nanostructure-containing material is integrated into the anode by electrophoresis, dielectrophoresis, CVD, screen printing, and mechanical methods.