General Electric Company

Erdogan O Gurmen

Robert J Riedner

Charles D Greskovich

Jiang Hsieh

David Michael Hoffman

Dominic A Cusano

Bing A Shen

William Paul Minnear

Gregory Scott Zeman

Matthew Aaron Halsmer

August O Englert

Chester R O'Clair

Matthew R Schedler

Timothy J Sporer

Aziz Ikhlef

Tyler Justin Sprenger

A method for obtaining data includes scanning an object with radiation to collect projection data using an imaging system having a detector array with detector cells and a post-patient collimator, wherein the post-patient collimator has plates having non-uniform thicknesses. The method further includes applying a correction to the projection data to shift an effective center of at least some of the detector cells to compensate for the non-uniform thicknesses of the collimator plates.

Method and apparatus for compensating non-uniform detector collimator plates

Apparatus and methods for fabricating scintillators for use in a CT systems are described. Adjacent scintillator elements are separated by gaps filled with a composition of white diffuse reflective material, a light absorber, and a castable polymer. The composition increases the strength of the signal to the photodiode by minimizing the amount of light that is lost by the scintillator elements. Additionally, the light absorber minimizes the amount of light transferred between adjacent scintillator elements to limit cross-talk. In addition, the outer edges of the scintillator may have a lower amount of light absorber to compensate for the light lost from the periphery.

Scintillator for a multi-slice computed tomograph system

Transparent, polycrystalline garnet bodies having desirable properties for use as laser material, luminescent x-ray scintillator materials and other uses are produced by mixing a chloride source solution of the desired cations with a basic ammonium solution to produce a precipitate having a substantially uniform composition which can be further processed to provide the desired transparent body. This precipitate is separated from the solution, dried, thermally decomposed at a temperature in the range from 700.degree. to 1,000.degree. C., pressed to form a compact, isostatically pressed at up to 60,000 psi to provide a green, unsintered compact having a density in the vicinity of 55% of theoretic density. That green compact is then sintered in oxygen at a temperature between 1,400.degree. and 1,700.degree. C. to produce the desired transparent body. Alternatively, the compact may be sintered in oxygen at temperatures in the range from about 1,400.degree. to about 1,600.degree. C. to a closed pore stage and then hot isostatically pressed at high pressure to provide the desired transparent body.

Transparent polycrystalline garnets

A polycrystalline ceramic scintillator is disclosed for radiographic applications which has received a controlled oxidation anneal to reduce radiation damage otherwise occuring when said scintillator is exposed to X radiation during conversion of said X radiation to the display image. The particular ceramic material treated in said manner comprises a densely sintered rare earth doped gadolinia containing metal oxide having a cubic crystal structure which has been annealed after sintering in a controlled oxygen containing atmosphere. A preferred ceramic composition comprises from about 5 mole percent up to about 50 mole percent Gd.sub.2 O.sub.3, between about 0.5 mole percent and 12 mole percent of a rare earth activator oxide selected from the group consisting of Eu.sub.2 O.sub.3 and Nd.sub.2 O.sub.3, and between about 0.0001 and 0.5 mole percent of at least one afterglow reducer selected from the group consisting of Pr.sub.2 O.sub.3 and Tb.sub.2 O.sub.3, and the remainder of said composition being Y.sub.2 O.sub.3. A treatment to produce said improved x-ray conversion medium is also disclosed along with radiographic imaging systems and methods employing said improved x-ray image conversion medium.

Solid state scintillator and treatment therefor

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Shorewood, WI, United States of America

Erdogan O Gurmen