System and method for providing normalization correction for image reconstruction in a reduced pitch spiral scan cone beam computed tomography imaging system

US6459756B1 · kind B1 · utility

Assignee

• Siemens Corporate Research, Inc. · US

Inventors

• Kwok C. Tam · Schenectady, US
• Günter Lauritsch · Nuremberg, DE
• Herbert Bruder · Hemhofen, DE

Key dates

• Filing date: Oct 30, 2001
• Grant date: Oct 1, 2002
• Expiry date: Oct 30, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S378/901
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A system and method for 3D image reconstruction in a spiral scan cone beam computed tomography (CT) imaging system that allows the pitch of spiral scan projection to be reduced by a factor of 1/n (where n=3, 5, 7, 9, etc), thereby increasing the x-ray dosage to obtain a higher S/N (signal-to-noise) ratio, while achieving efficient use of a fixed-size detector. In addition, an image reconstruction protocol computes a correction factor for integration planes that intersect the reduced-pitch spiral path (which surrounds a ROI) at only M<n locations within an angular range that is determined, e.g., for M=1 planes, based on mask boundaries applied to the cone beam data. Despite the reduced pitch, the M<n integration planes do not provide increased flux (in contrast to other integration planes that intersect the object and scan path in M&#8707;n locations).