Patent classifications
A61B6/4021
LOW-COST ESTIMATION AND/OR TRACKING OF INTRA-SCAN FOCAL-SPOT DISPLACEMENT
Systems/techniques that facilitate low-cost estimation and/or tracking of intra-scan focal-spot displacement are provided. In various embodiments, a system can cause a medical imaging scanner to perform an air scan. In various aspects, the system can access data produced by the medical imaging scanner and relating to the air scan, where the data can include a set of gantry angles swept by an X-ray tube during the air scan, where the data can include a set of intensity value matrices recorded by a multi-channel-multi-row detector during the air scan, and where the set of intensity value matrices respectively correspond to the set of gantry angles. In various instances, the system can compute a set of channel-spanning intensity slopes based on the set of intensity value matrices. In various cases, the system can apply a slope-to-displacement transfer function to the set of channel-spanning intensity slopes, thereby yielding a set of focal-spot displacements.
CORRECTION OF INTRA-SCAN FOCAL-SPOT DISPLACEMENT
Systems/techniques that facilitate correction of intra-scan focal-spot displacement are provided. In various embodiments, a system can access a first gantry angle of a medical scanner. In various aspects, the system can determine a first displacement of a focal-spot of the medical scanner based on the first gantry angle, by referencing a mapping that correlates gantry angles to focal-spot displacements. In various instances, the system can compensate, via one or more focal-spot position adjusters of the medical scanner, for the first displacement.
Computer tomograph
A computer tomograph operates by rigidly arranged x-ray tubes, which are components of emitter-detector elements, which form an emitter-detector ring opened by relocating one emitter-detector element. Each x-ray tube includes a cathode emitting electrons, and an anode arrangement having an anode. Each cathode has an orientation angle relative to the geometrical center axis of the computer tomograph. A tangential plane on the focal spot of the anode has a surface normal, which includes an anode angle with the center axis. X-ray radiation emitted from the focal spot is directed in a center radiation angle to an x-ray detector axially offset relative to the x-ray tubes. The quotient from the sum of the orientation angle, radiation angle and anode angle is between two ninths and two. Each cathode, interacting with an electrode arrangement of the x-ray tubes, produces a focal spot on one of selectable positions on the anode arrangement.
Method for obtaining a CT image of an object with heel effect compensation in image space
A method for obtaining a Computer Tomography (CT) image of an object reduces heel effect artefacts and includes generating x-rays using an x-ray source comprising an angled anode, recording at least one set of 2D projections of the object or a part thereof, and generating at least one 3D CT image of the object. Each 3D CT image is corrected, wherein scaling factors for slices of voxels are determined with at least one 3D CT calibration image that pictures similar or identical object structures of a calibration object placed within the x-ray beam path with respect to a y-direction. A contribution to grey values of voxels belonging to said object structures attributable to the slice position in the y direction is determined at least approximately, and the scaling factor for a respective slice of voxels is chosen such that it compensates for the determined grey value contribution for that slice.
Systems and methods for focal spot motion detection in both x- and y-directions and correction
A method for estimating motion of an X-ray focal spot is provided. The acts of the method include acquiring image data by causing X-rays to be emitted from the X-ray focal spot of an X-ray source toward a radiation detector comprising multiple channels, wherein a subset of the channels each have a collimator blade positioned above the respective channel. The acts of the method also include independently estimating X-ray focal spot motion in an X-direction for the X-ray focal spot relative to an isocenter of the radiation detector and in a Y-direction along a direction of the X-rays for the X-ray focal spot relative to the isocenter based on respective channel gains for a first channel and a second channel of the subset of the channels.
Pixel noise cancellation system
Some embodiments include a system, comprising: a plurality of pixels; a plurality of data lines coupled to the pixels; a plurality of switches coupling the pixels to the data lines; a plurality of readout circuits coupled to the data lines; control logic coupled to the readout circuits, the control logic configured to, for one of the pixels: acquire a first value for the pixel while the corresponding switch is in an off state; reset the corresponding readout circuit corresponding for the pixel; acquire a second value for the pixel after resetting the readout circuit; turn on the corresponding switch; acquire a third value for the pixel after turning on the corresponding switch; and combine the first value, the second value, and the third value into a combined value for the pixel.
Multi-pass computed tomography scans for improved workflow and performance
An x-ray imaging apparatus and associated methods are provided to execute multi-pass imaging scans for improved quality and workflow. An imaging scan can be segmented into multiple passes that are faster than the full imaging scan. Data received by an initial scan pass can be utilized early in the workflow and of sufficient quality for treatment setup, including while the another scan pass is executed to generate data needed for higher quality images, which may be needed for treatment planning. In one embodiment, a data acquisition and reconstruction technique is used when the detector is offset in the channel and/or axial direction for a large FOV during multiple passes.
Method for creating a synthetic mammogram on the basis of a dual energy tomosynthesis recording
A method is for creating a synthetic mammogram based upon a dual energy tomosynthesis recording of an examination region. In an embodiment the method includes making a low energy tomosynthesis recording with a first X-ray energy spectrum; making a high energy tomosynthesis recording with a second X-ray energy spectrum of relatively higher energy compared with the first X-ray energy spectrum, wherein the examination region includes a contrast medium distribution; determining a subtraction volume based upon the high energy tomosynthesis recording and the low energy tomosynthesis recording; generating a three-dimensional probability map with a weighting factor per voxel based upon the subtraction volume; and creating a synthetic mammogram based upon the three-dimensional probability map.
Fast 3D radiography using multiple pulsed X-ray sources in motion with C-arm
A C-Arm X-ray imaging system using multiple pulsed X-ray sources in motion to perform efficient and ultrafast 3D radiography is presented. X-ray sources mounted on a structure in motion to form an array. X-ray sources move simultaneously relative to an object on a pre-defined arc track at a constant speed as a group. Each individual source can also move rapidly around its static position in a small distance. When a source has a speed that is equal to group speed but with opposite moving direction, the source at one C-arm end and X-ray flat panel detector at other C-arm end are activated through an external exposure control unit so that source stay momentarily standstill. The C-arm provides 3D X-ray scan imaging over a wide sweep angle and in different position by rotation. The X-ray image can be analyzed by an artificial intelligence module for real-time diagnosis.
Fast 3D radiography with multiple pulsed X-ray sources by deflecting tube electron beam using electro-magnetic field
An X-ray imaging system using multiple pulsed X-ray sources to perform highly efficient and ultrafast 3D radiography is presented. There are multiple pulsed X-ray sources mounted on a structure in motion to form an array of sources. The multiple X-ray sources move simultaneously relative to an object on a pre-defined arc track at a constant speed as a group. Electron beam inside each individual X-ray tube is deflected by magnetic or electrical field to move focal spot a small distance. When focal spot of an X-ray tube beam has a speed that is equal to group speed but with opposite moving direction, the X-ray source and X-ray flat panel detector are activated through an external exposure control unit so that source tube stay momentarily standstill equivalently. 3D scan can cover much wider sweep angle in much shorter time and image analysis can also be done in real-time.