General Electric Company

John M Sandrik

Rowland F Saunders

Norbert Joseph Pelc

Michael F Gard

Paul Richard Granfors

Baojun Li

Xianfeng Ni

Jerry A Thomas

Gordon M Geiger

A method and apparatus for tomosynthesis image quality control for a tomosynthesis imaging system. The method and apparatus including: positioning a phantom having an edge of predetermined sharpness at a predetermined angle relative to an imaging plane of an x-ray detector; performing tomosynthesis acquisition and generating one or more slice images using one or more three-dimensional reconstruction algorithms; selecting a slice image to be measured from the one or more slice images; identifying a sharpest edge in the slice image to be measured, wherein the sharpest edge in the slice image to be measured includes the in-focus portion of the phantom; inputting the slice image to be measured and coordinates of the sharpest edge in the slice image to be measured into a modulation transfer function (MTF) algorithm; and, using the MTF algorithm, calculating the in-plane resolution and slice thickness of the slice image to be measured.

Method and apparatus for tomosynthesis image quality control

Systems, methods and apparatus are provided through which, in some embodiments, an electronic sensor is positioned in the field of projection of an X-ray source, and the electronic sensor measures the deviation between a visible light field and an X-ray field. In some embodiments, the deviation is scaled in reference to the position of the electronic sensor between an X-ray receptor and the X-ray source.

Systems, methods and apparatus for determining deviation of an x-ray field, a light field and a primary receptor

A CT system includes a pair of detectors in its detector array which measure x-ray intensity from a source after passing through a differential x-ray filter. The ratio of the signals produced by these two detector elements are input to a KV calculator which produces a signal indicative of x-ray tube voltage.

On-line measurement of x-ray tube voltage in a CT system

Indirect measurement of voltage applied to diagnostic x-ray tubes

An x-ray beam stop for high energy x-ray devices comprises a laminate structure of multiple layers of different Z materials which may include lead (Pb) and arranged in progressive Z order for a predetermined x-ray detector orientation.

X-ray beam stop

A phantom for simulating a patient during an X-ray exam that involves introducing a high contrast material into the patient. The phantom comprises a base and a first contrast element. The first contrast element is disposed within the base and has an X-ray attenuation greater than that of the base. The contrast ratio of the first contrast element to the base is approximately 50. In one embodiment of the phantom, the first contrast element contains iodine. In another embodiment, the base has a shape which occupies the entire field of view of the X-ray exam and the first contrast element is positioned substantially in the center of the field of view. In yet another embodiment of the phantom, a second contrast element is disposed within the base and has a contrast ratio to the base of approximately 1.5.

Phantom for simulating an X-ray exam patient

A method and apparatus for use in a medical x-ray imaging system of the type including an x-ray source, an image intensifier tube for providing a momentary x-ray image of a patient exposed to x-rays and a video camera having video processing circuits for providing signals representative of a video image of the x-ray image on the intensifier tube to a video monitor provides a flickerless image presentation on the video monitor when the x-ray exposure repetition rate is different from the field scan rate of the video camera. The apparatus enables this result by sensing initiation of a first x-ray exposure and setting the amplification of the video processing circuits to a first value for obtaining a suitable presentation of the image. The apparatus then scans the image on the video camera to provide a first field of image presentation to the video monitor with the amplification set at the first value. The apparatus then directs initiation of a subsequent scan of the image on the video camera prior to a second x-ray exposure and concurrently increases the amplification of the video processing circuits to a second value such that a second field of image presentation is generated having substantially the same intensity as the first field. Since each field is then presented with the same intensity level, the flicker effect associated with a non-synchronized presentation is avoided.

Reduction of flicker during video imaging of cine procedures

X-ray energy-difference images are obtained simultaneously by exposing a body to a broad energy spectrum x-ray beam while a radiographic film package is disposed between front and rear x-ray intensifying screens. The film package has two superimposed films with a light-opaque sheet between them. The front screen, on which the polyenergetic image beam emerging from the body is incident, is excited to luminescence by x-ray photons predominantly in one energy band and the rear screen is excited predominantly by photons in another band. The light opaque sheet preferably contains x-ray filter material for additional filtering of photons to increase the fraction of photons at said other band to which the rear screen is sensitive. A shadowgraph of a marker is formed on the film emulsions during x-ray exposure to aid in matching congruent picture elements on each film when the developed films are being read out to obtain signals corresponding to their intensities. Notches in the edges of the films and sheet serve as a code for indicating the type of screens with which the package can be used.

Film-based dual energy radiography

X-ray energy-difference images are obtained simultaneously by exposing a body to a broad energy spectrum X-ray beam while a radiographic film package is disposed between front and rear X-ray intensifying screens. The film package has two superimposed films with a light-opaque sheet between them. The front screen, on which the polyenergetic image beam emerging from the body is incident, is excited to luminescence by X-ray photons predominantly in one energy band and the rear screen is excited predominantly by photons in another band. The light opaque sheet preferably contains X-ray filter material for additional filtering of photons to increase the fraction of photons at said other band to which the rear screen is sensitive. A shadowgraph of a marker is formed on the film emulsions during X-ray exposure to aid in matching congruent picture elements on each film when the developed films are being read out to obtain signals corresponding to their intensities. Notches in the edges of the films and sheet serve as a code for indicating the type of screens with which the package can be used.

Growing community of inventors

Wauwatosa, WI, United States of America

John M Sandrik