Impact of a single distance phase retrieval algorithm on spatial resolution in X-ray inline phase sensitive imaging
Autor: | Farid H. Omoumi, Aimin Yan, Bradley Gregory, Muhammad U. Ghani, Hong Liu, Xizeng Wu, Bin Zheng |
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Rok vydání: | 2019 |
Předmět: |
Materials science
business.industry 010401 analytical chemistry Phase (waves) 01 natural sciences Article Dot pitch Imaging phantom Flat panel detector 0104 chemical sciences 010309 optics Optics Optical transfer function 0103 physical sciences Radiology Nuclear Medicine and imaging Spatial frequency business Phase retrieval Image resolution |
Zdroj: | Biomed Spectrosc Imaging |
ISSN: | 2212-8808 2212-8794 |
Popis: | A single-projection based phase retrieval method based on the phase attenuation duality principle (PAD) was used to compare the spatial resolution of the acquired phase sensitive and PAD processed phase retrieved images. An inline phase sensitive prototype was used to acquire the phase sensitive images. The prototype incorporates a micro-focus x-ray source and a flat panel detector with a 50 μm pixel pitch. A phantom composed of a 2 cm thick 50-50 adipose-glandular mimicking slab sandwiched with a 0.82 cm thick slanted PMMA sharp edge was used. Phase sensitive image of the phantom was acquired at 120 kV, 3.35 mAs with a 16 μm tube focal spot size under a geometric magnification (M) of 2.5. The PAD based method was applied to the acquired phase sensitive image for the retrieval of phase values. With necessary data processing, modulation transfer function (MTF) curves were determined for the estimation and comparison of the spatial resolution. The PAD processed phase retrieved values of the phantom were in good agreement with the theoretically calculated values. Phase sensitive images showed higher spatial resolution at all spatial frequencies compared to the phase retrieved images. It was noted that the high-frequency signal components in the retrieved image were suppressed that resulted in lower MTF values. When compared to the phase sensitive image, the cutoff resolution (10% MTF) for phase retrieved image dropped 32% from 15.6 lp/mm (32μm) to 10.6 lp/mm (47μm). The resolution offered by this phase sensitive prototype is radiographically enough to detect breast cancer. |
Databáze: | OpenAIRE |
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