A method and a system for a two-step calibration method for the polychromatic semiconductor-based PCD forward counting model, to account for various pixel summing readout modes for imaging at different resolutions. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at plural tube voltage settings for each detector pixel. To correct the variation of the detector response due to different PCD sub-pixel summing schemes, the embodiments calibrate forward model parameters based on the various pixel readout modes.

The disclosure herein relates to systems, methods, and devices for medical image analysis, diagnosis, risk stratification, decision making and/or disease tracking. In some embodiments, the systems, devices, and methods described herein are configured to analyze non-invasive medical images of a subject to automatically and/or dynamically identify one or more features, such as plaque and vessels, and/or derive one or more quantified plaque parameters, such as radiodensity, radiodensity composition, volume, radiodensity heterogeneity, geometry, location, and/or the like. In some embodiments, the systems, devices, and methods described herein are further configured to generate one or more assessments of plaque-based diseases from raw medical images using one or more of the identified features and/or quantified parameters.

The disclosure herein relates to systems, methods, and devices for medical image analysis, diagnosis, risk stratification, decision making and/or disease tracking. In some embodiments, the systems, devices, and methods described herein are configured to analyze non-invasive medical images of a subject to automatically and/or dynamically identify one or more features, such as plaque and vessels, and/or derive one or more quantified plaque parameters, such as radiodensity, radiodensity composition, volume, radiodensity heterogeneity, geometry, location, and/or the like. In some embodiments, the systems, devices, and methods described herein are further configured to generate one or more assessments of plaque-based diseases from raw medical images using one or more of the identified features and/or quantified parameters.

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.

A phantom for use in quality control of tomographic images, the phantom including a cylindrical plate made of a uniform material having a density d1, with two cylinders being inserted in the plate, the cylinders being made out of uniform materials having different densities d2, d3, the density of one of the cylinders being greater than the density d1 of the plate, and the density of the other cylinder being less than the density d1 of the plate, and including a first series of pairs of holes of different diameters drilled in the plate, the axes of the holes of the first series being oriented axially relative to an axis of revolution of the plate, and the holes in a given pair being spaced apart from each other by a distance equal to their diameter.

An imaging system generates a first radiograph based on a first pattern of radiation detected by a Linear Diode Array (LDA) radiation detector positioned to detect a radiation beam emitted by a radiation generator. The LDA radiation detector comprises a plurality of modules. Each respective module of the plurality of modules comprises a respective plurality of photodiodes corresponding to pixels. Furthermore, the imaging system may determine, based on the first radiograph, a size of a gap between two of the modules of the LDA radiation detector. After determining the size of the gap, the imaging system may generate a second radiograph based on a second pattern of radiation detected by the LDA radiation detector. The imaging system may generate a third radiograph by modifying, based on the size of the gap, the second radiograph to compensate for the gap.

Systems and methods are described for determining a minimum radiation dose for a computed tomography (CT) scanning device. The method includes receiving a first input indicative of a selected minimum detectable contrast and a second input indicative of an estimate of a size of a subject to be exposed to the radiation dose. A minimum radiation dose to be applied via a radiation source is determined. The minimum radiation dose is determined at least in part by a power law model relating the size of the subject, a lesion size, and a minimum detectable contrast. The power law model is defined as MDC=A(L) d.sup.B(L) Dose.sup.C(L), wherein (i) MDC is the selected minimum detectable contrast, (ii) d is lesion size, (iii) Dose is radiation dose, (iv) A(L), B(L), and C(L) are pre-determined fitted parameters, and (v) L is the estimate of the size of the subject.

An X-ray CT apparatus and a correction method of projection data that are capable of suppressing artifacts generated in the vicinity of an edge portion of a test subject are provided. The X-ray CT apparatus for photographing a test subject is characterized by comprising: a correction data creation unit that creates correction data using difference data between measurement projection data for each X-ray energy obtained by photographing a known phantom having a known composition, a known shape, and a size smaller than a photographing field of view of the X-ray CT apparatus and calculation projection data for each X-ray energy calculated on the basis of X-ray transmission lengths obtained from the shape of the known phantom; and a correction unit that corrects projection data for each X-ray energy of the test subject using the correction data.

The present invention provides a method for calibrating a working plane of a medical detection apparatus, which is used for calibrating the working plane of the medical detection apparatus to be parallel with a first reference plane, wherein the working plane has a first point to be calibrated and a second point to be calibrated thereon, the first point to be calibrated is located on the first reference plane, and the first point to be calibrated and the second point to be calibrated are respectively supporting points of a first foot and a second foot for supporting the working plane on the working plane, the above method comprising: receiving at least one first inclination angle value from an angle measuring tool, wherein each first inclination angle value is an angle between a line connecting the first point to be calibrated and the second point to be calibrated and the first reference plane; computing a vertical distance between the second point to be calibrated and the first reference plane as a first magnitude of adjustment according to a pre-stored distance between the first point to be calibrated and the second point to be calibrated and the first inclination angle value; and adjusting a height of the second foot according to the first magnitude of adjustment to allow the second point to be calibrated to be located on the first reference plane.

The invention relates generally to biopsy needle guidance which employs an x-ray/gamma image spatial co-registration methodology. A gamma camera is configured to mount on a biopsy needle gun platform to obtain a gamma image. More particular, the spatially co-registered x-ray and physiological images may be employed for needle guidance during biopsy. Moreover, functional images may be obtained from a gamma camera at various angles relative to a target site. Further, the invention also generally relates to a breast lesion localization method using opposed gamma camera images or dual opposed images. This dual head methodology may be used to compare the lesion signal in two opposed detector images and to calculate the Z coordinate (distance from one or both of the detectors) of the lesion.