Neil B Bromberg

US Patent:

6055290, Apr 25, 2000

Filed:

Aug 25, 1998

Appl. No.:

9/139992

Inventors:

Min Xie - Waukesha WI
Guy M. Besson - Wauwatosa WI
Neil B. Bromberg - Milwaukee WI

Assignee:

General Electric Company - Milwaukee WI

International Classification:

A61B 603

US Classification:

378 4

Abstract:

The present invention comprises a system and method for correcting for z-slope variations in detector cell outputs represented by data obtained by a scan in a CT system. According to one aspect of the invention, a final error factor, based upon a combination of a correction factor and an initial error factor, is applied to the data. The correction factor having a computational complexity independent of the order of correction desired. The present invention transfers all of the computational complexity of z-slope correction to a calibration process, thereby improving the computational speed and efficiency of producing an accurate image based on the scan data. In another aspect, the present invention improves image quality by providing a correction factor comprising a plurality of channel correction factors, where each of the plurality of channels is the center channel for a corresponding moving segment used to respectively determine each of the channel correction factors.

US Patent:

6411673, Jun 25, 2002

Filed:

Dec 29, 2000

Appl. No.:

09/751814

Inventors:

Neil B. Bromberg - Milwaukee WI

Assignee:

GE Medical Systems Global Technology Company, LLC - Waukesha WI

International Classification:

A61B 603

US Classification:

378 19, 378 8, 378901

Abstract:

Time consuming calibration of a multi-element x-ray detector for an x-ray computed tomography machine that has multi-sample rate capabilities is reduced by determining through the use of air-scans, a scalar relationship between sensitivity of detector elements as a function of sampling rate. This scalar relationship is in vector form and may be applied to independently obtain calibration vectors at a base scan rate to provide effective calibration vectors at a variety of scan rates without the need for time consuming daily calibration scans at each of those sample rates.

US Patent:

6411677, Jun 25, 2002

Filed:

Sep 10, 2001

Appl. No.:

09/950261

Inventors:

Thomas L. Toth - Brookfield WI
George E. Seidenschnur - Waukesha WI
Neil B. Bromberg - Milwaukee WI

Assignee:

General Electric Company - Schenectady NY

International Classification:

G21K 102

US Classification:

378147, 378 4

Abstract:

The present invention is, in one embodiment, a method for determining tracking control parameters for positioning an x-ray beam of a computed tomography imaging system having a movable collimator positionable in steps and a detector array including a plurality of rows of detector elements. The method includes steps of obtaining detector samples at a series of collimator step positions while determining a position of a focal spot of the x-ray beam; determining a beam position for each detector element at each collimator step utilizing the determined focal spot positions, a nominal focal spot length, and geometric parameters of the x-ray beam, collimator, and detector array; and determining a calibration parameter utilizing information so obtained. For example, in determining a target beam position at which to maintain the x-ray beam, a detector element differential error is determined according to ratios of successive collimator step positions; and a target beam position is selected for an isocenter element in accordance with the determined element differential errors.

US Patent:

7086780, Aug 8, 2006

Filed:

May 20, 2004

Appl. No.:

10/850009

Inventors:

Xiaoye Wu - Rexford NY, US
Neil Barry Bromberg - Milwaukee WI, US
Alexander Kolker - Milwaukee WI, US
Piero Ugo Simoni - Greenfield WI, US
Thomas Louis Toth - Brookfield WI, US

Assignee:

General Electric Company - Schenectady NY

International Classification:

G01D 18/00

US Classification:

378207, 378 5, 378 18, 378 19, 25036309

Abstract:

A method for calibrating a computed tomographic imaging apparatus having a gantry, a radiation source operable at a plurality of kVp's, and a detector array having a plurality of detector elements includes using a system detection function to estimate signals of each detector element that would have been detected through air and through a given thickness of water to determine estimated datasets. The estimated datasets are used to determine data pair sets each comprising a normalized water projection value and an ideal projection value for each detector element. The method further includes determining and storing a representation of a mapping function of the normalized water projections values to the ideal projection values in a memory of the computed tomographic imaging apparatus as a spectral calibration of the computed tomographic imaging apparatus.

US Patent:

7391844, Jun 24, 2008

Filed:

Jan 14, 2005

Appl. No.:

11/036618

Inventors:

Xiaoye Wu - Rexford NY, US
Piero Ugo Simoni - Greenfield WI, US
Thomas Louis Toth - Brookfield WI, US
Neil Barry Bromberg - Milwaukee WI, US

Assignee:

General Electric Company - Schenectady NY

International Classification:

A61B 6/00

US Classification:

378 18, 378207

Abstract:

A method for determining a correction for beam hardening in CT images includes obtaining air scans at a plurality of kVp's, determining detection efficiencies for detector elements of the CT imaging apparatus, and estimating projection values through a combination of at least two different materials of different thicknesses. The method further includes determining a transfer function that translates the estimated projection values into ideal projection values for at least two of the different materials and storing the transfer function as the beam hardening correction for images of the CT imaging apparatus.

US Patent:

63109387, Oct 30, 2001

Filed:

Aug 27, 1999

Appl. No.:

9/384937

Inventors:

Thomas L. Toth - Brookfield WI
George E. Seidenschnur - Waukesha WI
Neil B. Bromberg - Milwaukee WI

Assignee:

General Electric Company - Schenectady NY

International Classification:

G21K 100

US Classification:

378147

Abstract:

The present invention is, in one embodiment, a method for determining tracking control parameters for positioning an x-ray beam of a computed tomography imaging system having a movable collimator positionable in steps and a detector array including a plurality of rows of detector elements. The method includes steps of obtaining detector samples at a series of collimator step positions while determining a position of a focal spot of the x-ray beam; determining a beam position for each detector element at each collimator step utilizing the determined focal spot positions, a nominal focal spot length, and geometric parameters of the x-ray beam, collimator, and detector array; and determining a calibration parameter utilizing information so obtained. For example, in determining a target beam position at which to maintain the x-ray beam, a detector element differential error is determined according to ratios of successive collimator step positions; and a target beam position is selected for an isocenter element in accordance with the determined element differential errors.

US Patent:

63273292, Dec 4, 2001

Filed:

Aug 25, 1998

Appl. No.:

9/140110

Inventors:

Neil B. Bromberg - Milwaukee WI
Hui David He - Waukesha WI
Mary Sue Kulpins - New Berlin WI

Assignee:

General Electric Company - Schenectady NY

International Classification:

A61B 600
H05B 164
G01D 1800

US Classification:

378 19

Abstract:

Methods and apparatus for detecting cell to cell variation to ensure that the maximum allowable channel to channel variation is not exceeded are described. In one embodiment, an algorithm is periodically executed to measure the relative gains in the channels. The gains are measured, for example, by recording the signal from an air scan and normalizing to a common reference. Part of the normalization process includes accounting for the non uniformity of the x-ray beam, for example, the heel effect. It is assumed that the x-ray flux profile in z is slowly changing in the x-direction and is obtained by low pass filtering in x. The normalized values are then compared to a predetermined specification. If any particular cell is not within the specification parameters, then the module in which such cell resides may be replaced. In addition to measuring gain variation and comparing it to a specification, a trending analysis also may be performed.

US Patent:

63255391, Dec 4, 2001

Filed:

Jul 19, 1999

Appl. No.:

9/356535

Inventors:

Neil B. Bromberg - Milwaukee WI

Assignee:

General Electric Company - Schenectady NY

International Classification:

A61B 603

US Classification:

378207

Abstract:

Methods and apparatus for calibration simplification in a computed tomography (CT) system are described. In one embodiment, the CT system utilizes calibration values from a first scan type, or mode of operation, to determine calibration values for at least a second scan type. As a result, the time required to perform calibration of the CT system is reduced.