Abstract: An apparatus for cone beam computed tomography of an extremity has a digital radiation detector and a first device to move the detector along a circular detector path extending so that the detector moves both at least partially around a first extremity of the patient and between the first extremity and a second, adjacent extremity. The detector path has radius R1 sufficient to position the extremity approximately centered in the detector path. There is a radiation source with a second device to move the source along a concentric circular source path having a radius R2 greater than radius R1, radius R2 sufficiently long to allow adequate radiation exposure of the first extremity for an image capture by the detector. A first circumferential gap in the source path allows the second extremity to be positioned in the first circumferential gap during image capture.

Abstract: A method for providing a diagnostic image as a combination of two or more images executed, at least in part, on a control logic processor. The method includes obtaining at least first and second image data of a subject and analyzing both the first and second image data to identify at least grid orientation and spacing. Grid suppression is applied to the first and second image data and the grid suppressed first and second image data is pre-processed. The method then combines the grid suppressed first and second image data and decomposes the combined data to obtain one or more diagnostic images for display. The one or more diagnostic images are displayed on a display that is associated with the control logic processor.

Abstract: An apparatus for cone beam computed tomography of an extremity has a digital radiation detector and a first device to move the detector along a circular detector path extending so that the detector moves both at least partially around a first extremity of the patient and between the first extremity and a second, adjacent extremity. The detector path has radius R1 sufficient to position the extremity approximately centered in the detector path. There is a radiation source with a second device to move the source along a concentric circular source path having a radius R2 greater than radius R1, radius R2 sufficiently long to allow adequate radiation exposure of the first extremity for an image capture by the detector. A first circumferential gap in the source path allows the second extremity to be positioned in the first circumferential gap during image capture.

Abstract: An apparatus for cone beam computed tomography of an extremity has a digital radiation detector and a first device to move the detector along a circular detector path extending so that the detector moves both at least partially around a first extremity of the patient and between the first extremity and a second, adjacent extremity. The detector path has radius R1 sufficient to position the extremity approximately centered in the detector path. There is a radiation source with a second device to move the source along a concentric circular source path having a radius R2 greater than radius R1, radius R2 sufficiently long to allow adequate radiation exposure of the first extremity for an image capture by the detector. A first circumferential gap in the source path allows the second extremity to be positioned in the first circumferential gap during image capture.

Abstract: An apparatus for cone beam computed tomography of lower leg portions of a patient has a radiation source and a source transport actuable to move the source along an arcuate source path within a housing, from one side of a circumferential gap to the other and has a radius R2 about a center. A housing is provided for placement of the patient's foot. A digital radiation detector has a detector transport actuable to move the detector along an arcuate detector path within the housing, the detector path having a radius R1 about the center and concentric with the source path, wherein R1 is less than R2, and wherein the detector path extends from one side of the pedestal indent to the other. A gap closure apparatus is movable to a position that continues the detector path across the circumferential gap and encloses the detector path.

Abstract: A method is disclosed for generating a composite image from dual-energy projection radiographic image data and renormalizing the composite image such that the pixel values for the composite image have the same relationship to the detected x-ray energy as the original high- and low-energy images. The method disclosed further provides for renormalization of material specific decomposition images formed form dual energy projection radiographic image data such that the decomposition images are on a common scale with either the high-energy, low-energy or composite image.

Abstract: A method for 3-D volume image reconstruction of a subject, executed at least in part on a computer, obtains image data for 2-D projection images over a range of scan angles. For each of the plurality of projection images, a noise-corrected projection image is generated by steps of transforming the image data according to a variance-stabilizing transform to provide transformed image data, applying Gaussian based noise suppression to the transformed image data, and inverting the transformation of the noise-suppressed transformed image data to generate the noise-corrected projection image. The noise-corrected projection image is stored in a computer-accessible memory.

Abstract: An apparatus for cone beam computed tomography of lower leg portions of a patient has a radiation source and a source transport actuable to move the source along an arcuate source path within a housing, from one side of a circumferential gap to the other and has a radius R2 about a center. A housing is provided for placement of the patient's foot. A digital radiation detector has a detector transport actuable to move the detector along an arcuate detector path within the housing, the detector path having a radius R1 about the center and concentric with the source path, wherein R1 is less than R2, and wherein the detector path extends from one side of the pedestal indent to the other. A gap closure apparatus is movable to a position that continues the detector path across the circumferential gap and encloses the detector path.

Abstract: Acquisition techniques for dual energy (DE) chest imaging system. Technique factors include the added x-ray filtration, kVp pair, and the allocation of dose between low- and high-energy projections, with total dose equal to or less than that of a conventional chest radiograph. Factors are described which maximize lung nodule detectability as characterized by the signal difference to noise ratio (SDNR) in DE chest images. kVp pair and dose allocation are described using a chest phantom presenting simulated lung nodules and ribs for thin, average, and thick body habitus. Low- and high-energy techniques ranged from 60-90 kVp and 120-150 kVp, respectively, with peak soft-tissue SDNR achieved at [60/120] kVp for patient thicknesses and levels of imaging dose. A strong dependence on the kVp of the low-energy projection was observed.

Abstract: A method for obtaining a 3-D image. An initial volume image is obtained of a subject wherein the subject is stationary and in a first pose. One or more 2-D images of the subject are obtained as the subject is moving between the first pose and a second pose. An endpoint volume image of the subject with the subject stationary and in the second pose is obtained. At least the initial volume image is modified according to the one or more obtained 2-D images to form at least one intermediate volume image that is representative of the subject's position between the first and second pose. The at least one intermediate volume image can be displayed.

Abstract: A method for providing a diagnostic image as a combination of two or more images executed, at least in part, on a control logic processor. The method includes obtaining at least first and second image data of a subject and analyzing both the first and second image data to identify at least grid orientation and spacing. Grid suppression is applied to the first and second image data and the grid suppressed first and second image data is pre-processed. The method then combines the grid suppressed first and second image data and decomposes the combined data to obtain one or more diagnostic images for display. The one or more diagnostic images are displayed on a display that is associated with the control logic processor.

Abstract: A radiographic imaging apparatus for taking X-ray images of an object includes a front panel and back panel. The panels have substrates, arrays of signal sensing elements and readout devices, and passivation layers. The front and back panels have scintillating phosphor layers responsive to X-rays passing through an object produce light which illuminates the signal sensing elements to provide signals representing X-ray images. The X-ray apparatus has means for combining the signals of the X-ray images to produce a composite X-ray image. Furthermore, the composition and thickness of the scintillating phosphor layers are selected, relative to each other, to improve the diagnostic efficacy of the composite X-ray image. Alternatively, a radiographic imaging apparatus has a single panel having arrays of signal sensing elements and readout devices and scintillating phosphor layers that are disposed on both sides of a single substrate.

Abstract: An apparatus for cone beam computed tomography of an extremity has a digital radiation detector and a first device to move the detector along a circular detector path extending so that the detector moves both at least partially around a first extremity of the patient and between the first extremity and a second, adjacent extremity. The detector path has radius R1 sufficient to position the extremity approximately centered in the detector path. There is a radiation source with a second device to move the source along a concentric circular source path having a radius R2 greater than radius R1, radius R2 sufficiently long to allow adequate radiation exposure of the first extremity for an image capture by the detector. A first circumferential gap in the source path allows the second extremity to be positioned in the first circumferential gap during image capture.

Abstract: A method is disclosed for acquiring a high speed dual-energy image pair using a pixilated digital detector. A single pixilated digital detector acquires and encodes two separate images in effectively one image, eliminating the need to read out a first image prior to acquiring a second image. The encoded information is then utilized to obtain two distinct dual-energy images which may be decomposed to form bone and soft-tissue only images.

Abstract: Methods are provided for cardiac gating of multiple-energy projection radiographic imaging utilizing an apparatus that measures the patient's peripheral blood perfusion. The choice of methods is dependant on the patient's heart rate and the delays inherent in the imaging system. A first method allows for imaging during the diastole period of the current cardiac cycle. A second method provides an implemented delay to acquire the image during the diastole period of a subsequent cardiac cycle. The use of the apparatus that measures the patient's peripheral blood perfusion allows for an efficient and convenient means of cardiac gating while avoiding occlusion of diagnostically important anatomy.

Abstract: Acquisition techniques for dual energy (DE) chest imaging system. Technique factors include the added x-ray filtration, kVp pair, and the allocation of dose between low- and high-energy projections, with total dose equal to or less than that of a conventional chest radiograph. Factors are described which maximize lung nodule detectability as characterized by the signal difference to noise ratio (SDNR) in DE chest images. kVp pair and dose allocation are described using a chest phantom presenting simulated lung nodules and ribs for thin, average, and thick body habitus. Low- and high-energy techniques ranged from 60-90 kVp and 120-150 kVp, respectively, with peak soft-tissue SDNR achieved at [60/120] kVp for patient thicknesses and levels of imaging dose. A strong dependence on the kVp of the low-energy projection was observed.

Abstract: A radiographic imaging device has a first scintillating phosphor screen having a first thickness and a second scintillating phosphor screen having a second thickness. A transparent substrate is disposed between the first and second screens. An imaging array formed on a side of the substrate includes multiple photosensors and an array of readout elements.

Abstract: A radiographic imaging device has a first scintillating phosphor screen having a first thickness and a second scintillating phosphor screen having a second thickness. A transparent substrate is disposed between the first and second screens. An imaging array formed on a side of the substrate includes multiple photosensors and an array of readout elements.

Abstract: Methods are provided for cardiac gating of multiple-energy projection radiographic imaging utilizing an apparatus that measures the patient's peripheral blood perfusion. The choice of methods is dependant on the patient's heart rate and the delays inherent in the imaging system. A first method allows for imaging during the diastole period of the current cardiac cycle. A second method provides an implemented delay to acquire the image during the diastole period of a subsequent cardiac cycle. The use of the apparatus that measures the patient's peripheral blood perfusion allows for an efficient and convenient means of cardiac gating while avoiding occlusion of diagnostically important anatomy.

Abstract: A method is disclosed for generating a composite image from dual-energy projection radiographic image data and renormalizing the composite image such that the pixel values for the composite image have the same relationship to the detected x-ray energy as the original high- and low-energy images. The method disclosed further provides for renormalization of material specific decomposition images formed form dual energy projection radiographic image data such that the decomposition images are on a common scale with either the high-energy, low-energy or composite image.