Abstract: A cone-beam scanning system scans along a half circle. The reconstruction uses a weighting function which decreases for rows farther from the scan plane to take the redundancy of the projection data into account. Another embodiment uses a circle plus sparse helical scan geometry. Image data can be taken in real time.

Abstract: Cone beam volume CT breast imaging is performed with a gantry frame on which a cone-beam radiation source and a digital area detector are mounted. The patient rests on an ergonomically designed table with a hole or two holes to allow one breast or two breasts to extend through the table such that the gantry frame surrounds that breast. The breast hole is surrounded by a bowl so that the entire breast can be exposed to the cone beam. Spectral and compensation filters are used to improve the characteristics of the beam. A materials library is used to provide x-ray linear attenuation coefficients for various breast tissues and lesions.

Abstract: A cone-beam scanning system scans along a half circle. The reconstruction uses a weighting function which decreases for rows farther from the scan plane to take the redundancy of the projection data into account. Another embodiment uses a circle plus sparse helical scan geometry. Image data can be taken in real time.

Abstract: Disclosed are embodiments of methods of and systems for detecting and biopsying lesions with a cone beam computed tomography (CBCT) system. The system comprises, in some embodiments, a CBCT device configured to output a cone beam CT image of at least a portion of a patient's breast and a multi-axis transport module, having at least three degrees of freedom and configured to position a biopsy needle within a 3D frame of reference based on inputs received from the cone beam CT device. The transport module can be configured to place the biopsy needle adjacent to, or within, a target of interest within the breast. Also disclosed are embodiments of methods of and systems for testing CBCT systems with phantoms.

Abstract: Raw cone beam tomography projection image data are taken from an object and are denoised by a wavelet domain denoising technique and at least one other denoising technique such as a digital reconstruction filter. The denoised projection image data are then reconstructed into the final tomography image using a cone beam reconstruction algorithm, such as Feldkamp's algorithm.

Abstract: A cone beam CT imaging system incorporates the phase contrast in-line method, in which the phase coefficient rather than only the attenuation coefficient is used to reconstruct the image. Starting from the interference formula of in-line holography, the terms in the interference formula can be approximately expressed as a line integral that is the requirement for all CBCT algorithms. So, the CBCT reconstruction algorithms, such as the FDK algorithm, can be applied for the in-line holographic projections.

Abstract: A cone-beam scanning system scans along a half circle. The reconstruction uses a weighting function which decreases for rows farther from the scan plane to take the redundancy of the projection data into account. Another embodiment uses a circle plus sparse helical scan geometry. Image data can be taken in real time.

Abstract: Raw cone beam tomography projection image data are taken from an object and are denoised by a wavelet domain denoising technique and at least one other denoising technique such as a digital reconstruction filter. The denoised projection image data are then reconstructed into the final tomography image using a cone beam reconstruction algorithm, such as Feldkamp's algorithm.

Abstract: Cone beam volume CT breast imaging is performed with a gantry frame on which a cone-beam radiation source and a digital area detector are mounted. The patient rests on an ergonomically designed table with a hole or two holes to allow one breast or two breasts to extend through the table such that the gantry frame surrounds that breast. The breast hole is surrounded by a bowl so that the entire breast can be exposed to the cone beam. Spectral and compensation filters are used to improve the characteristics of the beam. A materials library is used to provide x-ray linear attenuation coefficients for various breast tissues and lesions.

Abstract: Cone beam volume CT breast imaging is performed with a gantry frame on which a cone-beam radiation source and a digital area detector are mounted. The patient rests on an ergonomically designed table with a hole or two holes to allow one breast or two breasts to extend through the table such that the gantry frame surrounds that breast. The breast hole is surrounded by a bowl so that the entire breast can be exposed to the cone beam. Spectral and compensation filters are used to improve the characteristics of the beam. A materials library is used to provide x-ray linear attenuation coefficients for various breast tissues and lesions.

Abstract: Cone beam volume CT breast imaging is performed with a gantry frame on which a cone-beam radiation source and a digital area detector are mounted. The patient rests on an ergonomically designed table with a hole or two holes to allow one breast or two breasts to extend through the table such that the gantry frame surrounds that breast. The breast hole is surrounded by a bowl so that the entire breast can be exposed to the cone beam. Spectral and compensation filters are used to improve the characteristics of the beam. A materials library is used to provide x-ray linear attenuation coefficients for various breast tissues and lesions.

Abstract: In cone-beam volume computed tomography or similar imaging techniques, the effects of x-ray scatter are reduced through using a beam compensation filter (a bow tie filter), air gap technique, and an antiscatter grid and corrected through the use of a beam stop array combined with interpolation or convolution operation. Images are taken with the beam stop array, and a larger number of images are taken without the beam stop array. The images taken with the beam stop array are spatially interpolated to derive scatter information, which is then angularly interpolated to provide as many scatter images as there are images taken without the beam stop array. The interpolations are performed through cubic spline interpolation or any other interpolation techniques or low-pass filtering operation (convolution operation with a selected kernel). Each scatter image is subtracted from a corresponding one of the images taken without the beam stop array to provide a sequence of scatter-corrected images.

Abstract: Cone beam volume computed tomography (CBVCT) is carried out by taking signals along an orbit having a circle plus two or more arcs. A reconstruction algorithm is provided to add a correction term to the Feldkamp algorithm and to use the arc data to reconstruct data which cannot be recovered from the circle scan. The part of the reconstruction algorithm for the circle orbit uses filtering functions to simplify digital signal processing. The part of the reconstruction algorithm for the arc orbits uses a window function to resolve data redundancy.

Abstract: Cone beam volume CT mammography is performed with a gantry frame on which a cone-beam radiation source and a digital area detector are mounted. The patient rests on an ergonomically designed table with a hole or two holes to allow one breast or two breasts to extend therethrough such that the gantry frame surrounds that breast. The gantry frame is rotatable so that the radiation source and the detector move in a circular orbit around the breast. In addition, the gantry frame is movable to describe a geometry other than a simple circle orbit, such as a circle plus one or more lines or a spiral.

Abstract: Cone-beam reconstruction is performed within a practically acceptable time on a computer having one or more microprocessors. The calculations involved in the reconstruction are divided into calculations to be performed on the MMX, ALU and SSE units of each of the microprocessors. For pure floating-point data, it is preferred to use the MMX unit to adjust the data address and map data and to use the SSE unit to perform the backprojection. The data are partitioned by z-line so that the data to be processed in each stage of the backprojection fit within the L1 cache.

Abstract: Cone-beam reconstruction is performed within a practically acceptable time on a computer having one or more microprocessors. The calculations involved in the reconstruction are divided into calculations to be performed on the MMX, ALU and SSE units of each of the microprocessors. For pure floating-point data, it is preferred to use the MMX unit to adjust the data address and map data and to use the SSE unit to perform the backprojection. The data are partitioned by z-line so that the data to be processed in each stage of the backprojection fit within the L1 cache.

Abstract: Only a single IV contrast injection with a short breathhold by the patient is needed for use with a volume CT scanner which uses a cone-beam x-ray source and a 2-D detector for fast volume scanning in order to provide true 3-D descriptions of vascular anatomy with more than 0.5 lp/mm isotropic resolution in the x, y and z directions is utilized in which one set of cone-beam projections is acquired while rotating the x-ray tube and detector on the CT gantry and then another set of projections is acquired while tilting the gantry by a small angle. The projection data is preweighted, partial derivatives are calculated and rebinned for both the circular orbit and arc orbit data The second partial derivative is then calculated and then the reconstructed 3-D images are obtained by backprojecting using the inverse Radon transform.

Abstract: A method of and system for performing intravenous tomographic digital angiography imaging which combines the principles of intravenous digital angiography with those of cone-beam volume tomography for generating a direct, unambiguous and accurate 3-D reconstruction of stenosis and other irregularities and malformations from 2-D cone-beam tomography projections is disclosed in which several different data acquisition geometries, such as a circle-plus-arc data acquisition geometry, may be utilized to provide a complete set of data so that an exact 3-D reconstruction is obtained. Only a single IV contrast injection with a short breathhold by the patient is needed for use with a volume CT scanner which uses a cone-beam x-ray source and a 2-D detector for fast volume scanning in order to provide true 3-D descriptions of vascular anatomy with more than 0.

Abstract: A method of and system for the 3-D reconstruction of an image from 2-D cone-beam tomography projections is disclosed in which a circle-plus-arc data acquisition geometry is utilized to provide a complete set of data so that an exact 3-D reconstruction is obtained. A volume CT scanner which uses a cone-beam x-ray source and a 2-D detector is utilized in which one set of cone-beam projections is acquired while rotating the x-ray tube and detector on the CT gantry and then another set of projections is acquired while tilting the gantry by a small angle. The projection data is preweighted and the partial derivatives of the preweighted projection data are calculated. Those calculated partial derivatives are rebinned to the first derivative of the Radon transform, for both the circular orbit data and the arc orbit data. The second partial derivative of the Radon transform is then calculated and then the reconstructed 3-D images are obtained by backprojecting using the inverse Radon transform.