Patent application number | Description | Published |
20090086888 | X-RAY CT APPARATUS AND IMAGE RECONSTRUCTION METHOD - An X-ray CT apparatus is provided for reducing the amount of computation at image reconstruction thereby to shorten an image reconstruction time. The X-ray CT apparatus comprises a cradle which moves in a horizontal direction to convey a subject to a photography space, an X-ray detector comprising a plurality of detecting clement rows, for obtaining projection data by a helical scan when the cradle is moved under acceleration/deceleration and at a constant velocity, and backprojection processing device for performing a backprojection process on the projection data. When image reconstruction is carried out using the projection data acquired when the cradle is moved under acceleration/deceleration, the backprojection processing device assumes a virtual image reconstruction plane P′ where the cradle is assumed to be moved at the constant velocity, with respect to an image reconstruction plane P of each view and backprojects projection data onto the virtual image reconstruction plane P′. | 04-02-2009 |
20090092224 | X-RAY CT APPARATUS - An X-ray CT apparatus enables decreasing the degradation of image quality and reducing futile exposure to X-ray in a helical shuttle scan. The X-ray CT apparatus comprises: a gantry rotating device having an X-ray generator for generating the X-ray and an X-ray detector for detecting the generated X-ray and transmitted through a subject; a gantry controller for performing the helical shuttle scan by reciprocally moving the gantry rotating device and the cradle; a scan condition setting device for setting the scan condition of the helical shuttle scan in a predetermined range in the direction of body axis of the subject; an X-ray projection data acquisition device for acquiring the X-ray projection data; a scan controller for controlling the scan as specified in the scan condition; and a image reconstruction device for performing the image reconstruction processing based on the X-ray projection data. | 04-09-2009 |
20090161822 | X-RAY CT APPARATUS AND IMAGE RECONSTRUCTING DEVICE - An X-ray CT apparatus includes image reconstructing device which specifies a first imaging range, a second imaging range and a third imaging range located between the first imaging range and the second imaging range in association with each position on a body axis of a subject, image-reconstructs a tomographic image included in the first imaging range using a first projection data amount necessary for image reconstruction of the tomographic image, image-reconstructs a tomographic image included in the second imaging range using a second projection data amount less than the first projection data amount, and image-reconstructs a tomographic image included in the third imaging range using a third projection data amount less than the first projection data amount and greater than the second projection data amount. | 06-25-2009 |
20100104313 | POWER SOURCE DEVICE AND IMAGE FORMING APPARATUS - A power source device includes an oscillator generating a clock, a frequency division unit dividing the clock to output a pulse, a sequence generation unit generating sequences “N” with respect to each switching of the pulse, a frequency division ratio setting unit setting frequency division ratio, a switching element driven by the pulse, and a piezoelectric transformer outputting alternating high voltage from a secondary-side when a primary-side is applied with voltage. The generated sequence and the set frequency division ratio are compared to output the pulses of fractional-M, −M+1 frequencies. An average frequency division ratio of the pulses of fractional-M, −M+1 frequencies determined by (M×α)+(M+1)×β/(α+β), where α and β respectively represent the number of pulses of “M” and “M+1” per unit time. The average frequency division ratio and frequency division ratio become equal at a sequence generation cycle and approximated in a period shorter than the sequence generation cycle. | 04-29-2010 |
20100172563 | X-RAY CT APPARATUS - An X-ray CT apparatus reconstructs a CT image (extended CT image) at each slice position lying outside a relative linear movement range at a helical scan or the like at low exposure and with high image quality. Scans each provided with a residence time are executed at relative linear movement start and end points (Zs and Zf). Projection data in a view range (F) corresponding to a predetermined view angle centering on a view (CVp | 07-08-2010 |
20100172564 | IMAGE RECONSTRUCTION METHOD AND X-RAY CT APPARATUS - An image reconstruction method includes a reconstruction algorithm of pixel data, weighting coefficients by which first projection data and second projection data at which a corresponding X-ray beam passes through a pixel lying on a reconstruction plane and which are opposite in view angle direction to each other, are to be multiplied, are calculated by equations each using a term of a distance between an X-ray generator and detector system and the reconstruction plane plus an offset distance at the acquisition of the projection data. | 07-08-2010 |
20100188011 | PIEZOELECTRIC TRANSFORMER DRIVING DEVICE, COLD-CATHODE TUBE INVERTER, COLD-CATHODE TUBE DRIVING DEVICE, AND IMAGE FORMING APPARATUS - A piezoelectric transformer driving device including: an oscillator; a frequency-divider outputting a pulse by dividing a clock signal from the oscillator by a frequency-divide ratio received thereto; a switching element driven by the pulse and intermittently applying a voltage to a primary side of a piezoelectric transformer; a frequency-divide ratio instructing unit holding a frequency-divide ratio instruction value of a real number having an integer part and an fractional part; a binarization unit binarizing the frequency-divide ratio instruction value into two different integer frequency-divide ratios and selectively outputting the frequency-divide ratios. The binarization unit adjusts an appearance ratio of the frequency-divide ratios such that an average of the frequency-divide ratios output from the binarization unit is equal to an average of the frequency-divide ratio instruction value. | 07-29-2010 |
20100202794 | POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS - A power supply device includes: an oscillator configured to output a clock signal; a pulse output unit configured to output a pulse by dividing the frequency of the clock signal; a switching element driven by the pulse; a piezoelectric transformer configured to intermittently receive a voltage from the switching element and to output a high alternating current voltage; a rectifier configured to convert the high alternating current voltage to a high direct current voltage; an output voltage conversion unit configured to convert the high direct current voltage to a low direct current voltage; a target setter configured to output a target value; and a comparison unit configured to compare the low direct current voltage with the target value and to output a comparison result. A frequency division ratio of the pulse is controlled according to the comparison result, and thereby is changed so as to obtain the target value. | 08-12-2010 |
20120219199 | IMAGE PROCESSING APPARATUS, PROGRAM AND IMAGE DIAGNOSTIC APPARATUS - An image processing apparatus is provided. The image processing apparatus includes an acquiring device configured to acquire a typical pixel value corresponding to a noted region in an image, a calculating device configured to calculated index values of variances in pixel values in the noted region or in both the noted region and a region adjacent to the noted region, a first enhancement degree determination device configured to determine an enhancement degree according to the acquired typical pixel value and each of the calculated index values, and an image processing device configured to perform high-frequency enhancement processing on the noted region, based on the enhancement degree determined by the first enhancement degree determination device. | 08-30-2012 |
20130101195 | IMAGE PROCESSING APPARATUS, PROGRAM AND IMAGE DIAGNOSTIC APPARATUS - An image processing apparatus is provided. The image processing apparatus includes an acquiring device configured to acquire a typical pixel value corresponding to a noted region in an image, a calculating device configured to calculated index values of variances in pixel values in the noted region or in both the noted region and a region adjacent to the noted region, a first enhancement degree determination device configured to determine an enhancement degree according to the acquired typical pixel value and each of the calculated index values, and an image processing device configured to perform high-frequency enhancement processing on the noted region, based on the enhancement degree determined by the first enhancement degree determination device. | 04-25-2013 |
20130243152 | IMAGE GENERATING METHOD, IMAGE GENERATING APPARATUS AND RADIATION TOMOGRAPHIC IMAGING APPARATUS, AND PROGRAM THEREFOR - An image generating method is provided. The method includes performing a rearrangement process and an interpolation process on fan beam projection data, the fan beam projection data acquired by a scan that includes rotating a radiation source and a detector having a plurality of detecting elements arranged in a channel direction, wherein the interpolation process generates equally-spaced parallel beam projection data in which channel-direction intervals are equal therebetween, and wherein the interpolation process is performed with respect to a plurality of view directions. The method further includes performing a back-projection process on the equally-spaced parallel beam projection data to thereby reconstruct an image, wherein the channel-direction intervals between the equally-spaced parallel beam projection data are smaller than a reference interval obtained by dividing an interval between the detecting elements in the channel direction by a projection enlargement rate. | 09-19-2013 |
20130343508 | IMAGE PRODUCING METHOD, IMAGE PRODUCING APPARATUS AND RADIATION TOMOGRAPHIC IMAGING APPARATUS, AND PROGRAM - An image producing method is provided. The method includes acquiring regular-interval parallel-beam projection data whose intervals in a channel direction are the same and parallel to each other in a plurality of view directions by applying interpolation processing in a view direction, rearrangement processing, and interpolation processing in the channel direction to fan-beam projection data, and reconstructing an image by applying back projection processing to the acquired regular-interval parallel-beam projection data, wherein the interpolation processing in the view direction includes interpolation processing which is performed along a curve or a first straight line made by deforming or rotating a second straight line parallel to the view direction so as to be proximate to a trajectory drawn by dots corresponding to a desired position in a Scan Field Of View region on a sinogram of the collected fan-beam projection data in the plurality of views. | 12-26-2013 |
20140146938 | IMAGE GENERATING METHOD, IMAGE GENERATING APPARATUS AND RADIATION TOMOGRAPHIC IMAGING APPARATUS, AND PROGRAM THEREFOR - An image generating method is provided. The method includes performing a rearrangement process and an interpolation process on fan beam projection data, the fan beam projection data acquired by a scan that includes rotating a radiation source and a detector having a plurality of detecting elements arranged in a channel direction, wherein the interpolation process generates equally-spaced parallel beam projection data in which channel-direction intervals are equal therebetween, and wherein the interpolation process is performed with respect to a plurality of view directions. The method further includes performing a back-projection process on the equally-spaced parallel beam projection data to thereby reconstruct an image, wherein the channel-direction intervals between the equally-spaced parallel beam projection data are smaller than a reference interval obtained by dividing an interval between the detecting elements in the channel direction by a projection enlargement rate. | 05-29-2014 |