Di Wu1, Aimin Yan2, Yuhua Li1, Molly D Wong1, Bin Zheng1, Xizeng Wu2, Hong Liu1. 1. Center of Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019. 2. Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35249.
Abstract
PURPOSE: In this research, a high-energy in-line phase contrast tomosynthesis prototype was developed and characterized through quantitative investigations and phantom studies. METHODS: The prototype system consists of an x-ray source, a motorized rotation stage, and a CMOS detector with a pixel pitch of 0.05 mm. The x-ray source was operated at 120 kVp for this study, and the objects were mounted on the rotation stage 76.2 cm (R1) from the source and 114.3 cm (R2) from the detector. The large air gap between the object and detector guarantees sufficient phase-shift effects. The quantitative evaluation of this prototype included modulation transfer function and noise power spectrum measurements conducted under both projection mode and tomosynthesis mode. Phantom studies were performed including three custom designed phantoms with complex structures: a five-layer bubble wrap phantom, a fishbone phantom, and a chicken breast phantom with embedded fibrils and mass structures extracted from an ACR phantom. In-plane images of the phantoms were acquired to investigate their image qualities through observation, intensity profile plots, edge enhancement evaluations, and/or contrast-to-noise ratio calculations. In addition, the robust phase-attenuation duality (PAD)-based phase retrieval method was applied to tomosynthesis for the first time in this research. It was utilized as a preprocessing method to fully exhibit phase contrast on the angular projection before reconstruction. RESULTS: The resolution and noise characteristics of this high-energy in-line phase contrast tomosynthesis prototype were successfully investigated and demonstrated. The phantom studies demonstrated that this imaging prototype can successfully remove the structure overlapping in phantom projections, obtain delineate interfaces, and achieve better contrast-to-noise ratio after applying phase retrieval to the angular projections. CONCLUSIONS: This research successfully demonstrated a high-energy in-line phase contrast tomosynthesis prototype. In addition, the PAD-based method of phase retrieval was combined with tomosynthesis imaging for the first time, which demonstrated its capability in significantly improving the contrast-to-noise ratios in the images.
PURPOSE: In this research, a high-energy in-line phase contrast tomosynthesis prototype was developed and characterized through quantitative investigations and phantom studies. METHODS: The prototype system consists of an x-ray source, a motorized rotation stage, and a CMOS detector with a pixel pitch of 0.05 mm. The x-ray source was operated at 120 kVp for this study, and the objects were mounted on the rotation stage 76.2 cm (R1) from the source and 114.3 cm (R2) from the detector. The large air gap between the object and detector guarantees sufficient phase-shift effects. The quantitative evaluation of this prototype included modulation transfer function and noise power spectrum measurements conducted under both projection mode and tomosynthesis mode. Phantom studies were performed including three custom designed phantoms with complex structures: a five-layer bubble wrap phantom, a fishbone phantom, and a chicken breast phantom with embedded fibrils and mass structures extracted from an ACR phantom. In-plane images of the phantoms were acquired to investigate their image qualities through observation, intensity profile plots, edge enhancement evaluations, and/or contrast-to-noise ratio calculations. In addition, the robust phase-attenuation duality (PAD)-based phase retrieval method was applied to tomosynthesis for the first time in this research. It was utilized as a preprocessing method to fully exhibit phase contrast on the angular projection before reconstruction. RESULTS: The resolution and noise characteristics of this high-energy in-line phase contrast tomosynthesis prototype were successfully investigated and demonstrated. The phantom studies demonstrated that this imaging prototype can successfully remove the structure overlapping in phantom projections, obtain delineate interfaces, and achieve better contrast-to-noise ratio after applying phase retrieval to the angular projections. CONCLUSIONS: This research successfully demonstrated a high-energy in-line phase contrast tomosynthesis prototype. In addition, the PAD-based method of phase retrieval was combined with tomosynthesis imaging for the first time, which demonstrated its capability in significantly improving the contrast-to-noise ratios in the images.
Authors: Muhammad U Ghani; Molly D Wong; Liqiang Ren; Di Wu; Bin Zheng; John X Rong; Xizeng Wu; Hong Liu Journal: Nucl Instrum Methods Phys Res A Date: 2017-02-16 Impact factor: 1.455
Authors: Di Wu; Molly Donovan Wong; Yuhua Li; Laurie Fajardo; Bin Zheng; Xizeng Wu; Hong Liu Journal: Phys Med Biol Date: 2017-11-21 Impact factor: 3.609
Authors: Di Wu; Molly Donovan Wong; Kai Yang; Aimin Yan; Yuhua Li; Laurie Fajardo; Bin Zheng; Xizeng Wu; Hong Liu Journal: IEEE Trans Biomed Eng Date: 2017-08-21 Impact factor: 4.538
Authors: Muhammad U Ghani; Molly D Wong; Di Wu; Bin Zheng; Laurie L Fajardo; Aimin Yan; Janis Fuh; Xizeng Wu; Hong Liu Journal: Phys Med Biol Date: 2017-04-05 Impact factor: 3.609
Authors: Muhammad U Ghani; Molly D Wong; Farid H Omoumi; Bin Zheng; Laurie L Fajardo; Aimin Yan; Xizeng Wu; Hong Liu Journal: Phys Med Date: 2018-02-23 Impact factor: 2.685