Method of and system for destreaking the photoelectric image in multi-energy computed tomography

• US 20050271293A1
• Filed: 06/04/2004
• Published: 12/08/2005
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Analogic Corporation
• Original Assignee: Analogic Corporation
• Inventors: Crawford, Carl R., Simanovsky, Sergey, Ying, Zhengrong, Naidu, Ram
• Granted Patent: US 7,415,147 B2
• Time in Patent Office: Days
• US Class Current: 382/254
• CPC Class Codes: G06T 2200/04 involving 3D image data
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/30112 Baggage; Luggage; Suitcase
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/77 Retouching; Inpainting; Scratch removal

Abstract

A method of and a system for destreaking the photoelectric image in multi-energy computed tomography are provided, wherein the photoelectric projections are generated from the projection data acquired using at least two x-ray spectra for scanned objects; wherein a neighboring scheme is provided; the method comprises computing the statistics including mean and standard deviation using the neighboring scheme; calculating an upper limit and a lower limit from the computed statistics; detecting outliers in the photoelectric projections using the upper and lower limits; and replacing values of outliers using the upper or lower limit.

Claims

1. A method of destreaking the photoelectric image in multi-energy X-ray computed tomography, wherein a set of photoelectric projections is provided, wherein a neighboring scheme is also provided, for each photoelectric projection data point, comprising:

A. Computing the mean and the standard deviation of the neighbors defined by the neighboring scheme;

B. Calculating an upper limit and a lower limit from the computed mean and standard deviation;

C. Detecting an outlier using the calculated upper and lower limits; and

D. Replacing the detected outliers with replacements.

2. The method of claim 1, wherein the said neighboring scheme includes a six-surface-neighbor scheme.

3. The method of claim 1, wherein said replacements include the upper or lower limits.

4. A system for destreaking the photoelectric image in multi-energy X-ray computed tomography, wherein a set of photoelectric projections and a neighboring scheme are provided, comprising:

A. A subsystem is constructed and arranged so as to compute the mean and the standard deviation of the neighbors defined by the neighboring scheme;

B. A subsystem is constructed and arranged so as to calculate an upper limit and a lower limit from the computed mean and standard deviation;

C. A subsystem is constructed and arranged so as to detect an outlier using the calculated upper and lower limits; and

D. A subsystem is constructed and arranged so as to replace the detected outlier with replacements.

5. The system of claim 4, wherein the said neighboring scheme includes a six-surface-neighbor scheme.

6. The system of claim 4, wherein said replacements include the upper or lower limits.