Program Information
In-Vivo Evaluation of Prospective Respiratory Gated Stationary Digital Chest Tomosynthesis Imaging
A Hartman*, E Gunnell , C Inscoe , J Lu , O Zhou , Y Lee , The University of North Carolina at Chapel Hill, Chapel Hill, NC
Presentations
WE-G-601-9 (Wednesday, August 2, 2017) 4:30 PM - 6:00 PM Room: 601
Purpose: To quantify the benefit of prospectively gated stationary digital chest tomosynthesis (Gs-DCT) using a carbon nanotube (CNT) x-ray source array in a free breathing porcine study.
Methods: The Gs-DCT x-ray system consists of a linear x-ray array tube (80kVp, 0.125mAs per projection for 29 projections over a 12° angular span) and a flat panel detector (5 fps). A respiratory trace was acquired through a transducer belt around the thorax. Each gated projection image was acquired at the temporal coincidence of the detector integration time and the peak inhalation of the pig. The projection images were reconstructed using iterative reconstruction with a 2mm slice thickness. Image blur was assessed as the reproduction of the diaphragm in the reconstructed images. Respiratory phase timing quality was assessed through cross-correlation analysis.
Results: The scan time for the gated scan was 86.9s ± 2.9s compared to the un-gated scanning time 6.3s ± .6s. An entrance dose of 0.4mSv was used. The blur in the reproduction of the diaphragm in the reconstructed images for gated study was 3.7 ± .2mm where in the un-gated case the diaphragm was 9.6±0.1mm. The average cross correlation coefficient of the respiratory trace at the time of the x-ray pulse was .91 ± .02 for the gated scan and .11±.01 for the un-gated scan.
Conclusion: Prospective gated imaging significantly reduced motion blur, substantially improving the image quality of the tomosynthesis images. The CNT based x-ray source array enables precise x-ray pulse generation on demand. If enabled clinically, the Gs-DCT system could potentially obtain 3D image stacks in patients that are unable to hold their breath, such as pediatric or intubated patient populations. Prospectively gated human studies are planned.
Funding Support, Disclosures, and Conflict of Interest: Jianping Lu, Otto Zhou, and Yueh Z. Lee of this abstract has equity ownership in, serves as an adviser for, or serves on the board of directors of Xinray and Xintech to which the x-ray source used in this paper has been and will be licensed.
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