Correction method for differential phase contrast imaging

US8855265B2 · kind B2 · utility

Assignee

• KONINIKLIJKE PHILIPS N.V. · NL

Inventors

• Klaus Juergen Engel · Aachen, DE
• Dieter Geller · Aachen, DE
• Gereon Vogtmeier · Aachen, DE

Key dates

• Filing date: Jun 10, 2010
• Grant date: Oct 7, 2014
• Expiry date: Mar 17, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G21K2207/005
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The present invention generally refers to a correction method for grating-based X-ray differential phase contrast imaging (DPCI) as well as to an apparatus which can advantageously be applied in X-ray radiography and tomography for hard X-ray DPCI of a sample object or an anatomical region of interest to be scanned. More precisely, the proposed invention provides a suitable approach that helps to enhance the image quality of an acquired X-ray image which is affected by phase wrapping, e.g. in the resulting Moiré interference pattern of an emitted X-ray beam in the detector plane of a Talbot-Lau type interferometer after diffracting said X-ray beam at a phase-shifting beam splitter grating. This problem, which is further aggravated by noise in the obtained DPCI images, occurs if the phase between two adjacent pixels in the detected X-ray image varies by more than π radians and is effected by a line integration over the object's local phase gradient, which induces a phase offset error of π radians that leads to prominent line artifacts parallel to the direction of said line integration.