229 results about "X ray dose" patented technology

An imaging system includes an X-ray source adapted to move in an arc shaped path and a stationary electronic X-ray detector. The system also includes a track and a mechanical driving mechanism which is adapted to move the X-ray source in the arc shaped path. A tomosynthesis X-ray imaging method includes mechanically moving an X-ray source in a stepped motion on an arc shaped path around an object using a track and irradiating the object with an X-ray dose from the X-ray source located at a plurality of steps along the arc shaped path. The method also includes detecting the X-rays transmitted through the object with an electronic X-ray detector, and constructing a three dimensional image of the object from a signal output by the electronic X-ray detector.

A method and device for producing visually sensed images of the internal structure of, particularly, a biological object. When used for diagnostic purposes in medicine the x-ray dosage of tissues surrounding the spot that is being examined is decreased.

A method and system for performing fluoroscopic imaging of a subject has high temporal and spatial resolution in a center portion of the captured dynamic images. The system provides for reduced X-ray dose to the patient associated with that part of the X-ray beam associated with a peripheral portion of the captured images although temporal, and in some embodiments spatial, resolution is reduced in the peripheral portion of the image. The system uses a rotating collimator to produce an X-ray beam having narrow wing portions associated with the peripheral portions of the image, and a broader central region associated with the high resolution center portion of the images.

Embodiments of methods and/or apparatus for 3-D volume image reconstruction of a subject, executed at least in part on a computer for use with a digital radiographic apparatus can obtain image data for 2-D projection images over a range of scan angles. For each of the plurality of projection images, an enhanced projection image can be generated. In embodiments of imaging apparatus, CBCT systems, and methods for operating the same can, through a de-noising application based on a different corresponding object, maintain image reconstruction characteristics (e.g., for a prescribed CBCT examination) while reducing exposure dose, reducing noise or increase a SNR while an exposure setting is unchanged.

The present invention relates to an apparatus for aiding operation of an interventional x-ray imager during image acquisition, to a method of aiding operation of an x-ray imager, to an interventional x-ray imager, to a computer program element and to a computer readable medium. The X-ray imager is capable of varying X-ray dosages depending on differences in X-ray attenuation levels across an object of interest to be imaged and is capable of assuming any one of a plurality of imaging geometry positions when acquiring an image. An indication, visual, acoustic or haptic, to the operator of an X-ray imager is provided on the incurred change in X-ray dosage when changing from a current projection view to an updated projection view, provided that a given constant image quality is to be maintained throughout the different views.

A system and method are disclosed for computing a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient. The CT image dataset generated during the scan of the patient, and one or more parameters relating to a x-ray source are used to calculate the radiation dose delivered to the patient as a function of the CT image data set and the one or more parameters of the x-ray source. The radiation dose is generally found by calculating a primary x-ray dose distribution and scattered x-ray dose distribution from the CT image dataset and taking the sum of the primary x-ray dose distribution and scattered x-ray dose distribution.

In a method and device for producing a tomosynthetic 3D x-ray image, a number of 2D projection images of an examination subject are acquired using a fixed x-ray source. The x-ray source has multiple, individually controllable emitters that respectively emit a single x-ray dose from various different directions. The tomosynthetic 3D image is reconstructed from the individual 2D projection images, and at least one 2D projection image is composed of multiple individual images.

In a tomography apparatus and a method for operating a tomography apparatus for generation of multiple energy images, in which high-energy projections and low-energy projections are acquired by alternating adjustment of a voltage and a further control variable (namely the current or the exposure time), given a set first voltage value and a set first control value of the further control variable, and given a set second voltage value and a set second control value of the further control variable, x-rays generated by an x-ray radiator exhibit essentially the same x-ray dose or photon flow.

The invention relates to an on-line dose modulation method of an X-ray CT (Computed Tomography) machine, which comprises the following steps: scanning plain film data, extracting Z-direction attenuation information of a human body, and calculating the attenuation area of the human body in each cut film along the Z direction; according to the attenuation area, calculating the average X-ray dose in each cut film to form a dose distribution curve along the Z direction, and supplying to a user as an initial recommended value, so that the user can adjust the dose distribution in the Z direction as required; scanning a patient, and simultaneously carrying out on-line estimation on the attenuation value of the rotation direction of the patient to obtain an attenuation estimated value; combining the dose distribution in the Z direction with the attenuation estimated value of the human body in the rotation direction to calculate a bulb tube mA value; transmitting the mA value to a high-pressure system, and carrying out high-frequency dose adjustment; and finishing the on-line dose modulation process if the scanning is completed. The invention reduces the overexposure and underexposure possibly caused by assuming sine laws. Besides, the invention does not assume that what passes through the central passage is the maximum attenuation, so that the dose modulation is better matched with the shape of the actual object.

Projection data acquired with an x-ray CT system is filtered using a bilateral filter to reduce image noise and enable the acquisition at lower x-ray dose without the loss of image diagnostic quality. The bilateral filtering is performed before image reconstruction by producing a noise equivalent data set from the acquired projection data and then converting the bilateral filtered values back to a projection data set suitable for image reconstruction.

A spectrometer for detecting and quantifying elements in a sample. An exciter ionizes atoms in the sample, and the atoms thereby produce characteristic x-rays. A detector receives the x-rays and produces signals based on the x-rays. A filter system selectively blocks the x-rays from attaining the detector. The selective blocking of the x-rays is accomplished based on an energy of the x-rays. An analyzer receives the signals from the detector and detects and quantifies the elements in the sample based at least in part on the signals. In this manner, detector receives the light element x-rays, and the medium and heavy element x-rays are filtered out to avoid overwhelming the detector. This invention combines the large solid angle, high efficiency, and ability to measure the continuous background spectrum of the energy dispersive x-ray detector with the selectivity of the wavelength dispersive x-ray detector. It thus enables faster and more accurate measurement of light elements in thin films. This invention enhances the light element performance of a system by enabling higher throughput, lower e-beam and x-ray dose to the sample, and improved accuracy from the capability to measure the background radiation.

X-ray devices for Phase Contrast Imaging (PCI) are often built up with the help of gratings. For large field-of-views (FOV), production cost and complexity of these gratings could increase significantly as they need to have a focused geometry. Instead of a pure PCI with a large FOV, this invention suggests to combine a traditional absorption X-ray-imaging system with large-FOV with an insertable low-cost PCI system with small-FOV, The invention supports the user to direct the PCI system with reduced FOV to a region that he regards as most interesting for performing a PCI scan thus eliminating X-ray dose exposure for scanning regions not interesting for a radiologist. The PCI scan may be generated on the basis of local tomography.

To perform a method for the reconstruction of a patient's body map, a detector has, in addition to the conventional sensors, an antenna placed in the direction of emission of the X-rays. At each position of the parts moving about the patient, electrodes of the antenna and the sensors simultaneously measure a distance between the patient's body and the detector. Means are used to carry out this reconstruction on the basis of the measured distances. The apparatus has means to achieve the following on the basis of this reconstruction: automatic control of the speeds of the moving parts of the apparatus, regulation of the X-ray dose and computation of the time of exposure to the X-rays.

The present invention relates to 3D-originated cardiac roadmapping. In order to improve the accuracy of the information provided to the user as navigation information, without any additional burden to the patient such as additional X-ray dose, a method is described comprising the steps of a) providing 3D+t image data of a vascular structure of an object; b) acquiring two-dimensional image data of the object, which object comprises the vascular structure, the 2D image data comprising at least one 2D image; c) projecting the vascular structure, thereby generating a plurality of mask images on the basis of a 3D+t image data; d) registering the at least one 2D image with one of the plurality of the mask images, wherein the registration comprises finding the maximum of a similarity factor between the mask images and the at least one 2D image; e) generating a combination of the at least one 2D image and a projection of the vascular structure on the basis of the 3D+t image data according to the registration; and f) displaying the combination as a guiding vessel tree projection. Thus improved cardiac roadmapping in form of a topographical roadmapping is provided since the roadmapping is based on three-dimensional data.

[Problems] To provide an X-ray CT apparatus capable of easily comparing image quality supposed to be obtained when not using a X-ray dose optimization function and image quality supposed to be obtained when using the X-ray dose optimization function at the stage of scan planning.

[Means for Solving Problems] A 3-dimensional model of an object to be examined (17) is generated from scanogram projection data (S170). An image noise dispersion value corresponding to an imaging region of the object is predicted from the 3-dimensional model.

The predicted image noise dispersion value is compared to a desired value of the image index value inputted by a user so as to calculate a modulation pattern of the irradiation X-ray amount (S200).

By predicting the image quality supposed to be obtained when using and not using the X-ray dose optimization function, each of the predicted results is displayed so as to be compared on a display device (5) (S230).