Yuncheng Zhong PhD, Presenter: Nothing to Disclose

Chao-Jen Lai PhD, Abstract Co-Author: Nothing to Disclose

Youtao Shen, Abstract Co-Author: Nothing to Disclose

Chris Chorng-Gang Shaw PhD, Abstract Co-Author: Investigator, Stellarray, Inc Editor, Taylor & Francis Group, LLC

Digital tomosynthesis (DTS) is able to crudely separate the overlapping anatomical structures on chest radiography. However, the resolution in the posterior-anterior (PA) view is quite limited due to the nature of DTS. Furthermore, the spillover of high-contrast objects from off-fulcrum planes generates artifacts. We demonstrate that by applying a dual-view DTS on chest imaging, the spatial resolution in PA direction is improved and the artifacts are alleviated.

We proposed a dual-view DTS technique in which projection images are acquired in two orthogonal views and reconstructed using an iterative method. We acquired cone beam CT images of an anthropomorphic chest phantom with 300 projections and an angular step size of 1.2°. The experiment was carried out using 120kVp, 40mA continuous mode x-ray, with source-to-detector distance of 180cm. The flat panel detector had a pixel size of 0.2mm. The dual-view DTS images were extracted from the CBCT images with different angular ranges and step sizes to investigate the effects of these parameters. We extracted the DTS data with the angular ranges of 30° and 60° respectively, each of which was using 1.2° and 2.4° angular step sizes. Single-view DTS images were also extracted and reconstructed for comparison. Visual inspection as well as the quantitative analysis of root-mean-squared-deviation (RMSD) and the thick slice thickness were used for evaluation.

The dual-view DTS images were fairly accurate in depicting the shape and dimensions of the anatomy in the fulcrum, especially for the sagittal views. The RMSD values calculated on different regions demonstrated the improvement of the image quality in dual-view DTS over single-view DTS. The thick slice thickness was greatly reduced for dual-view DTS. Our results also demonstrated that the RMSD and thick slice thickness with 60° angular range was better than with 30° angular range, and the a smaller angular step size with the same angular range resulted better quality images.

With a similar number of projections, dual-view DTS can render more accurate 3D images than single-view DTS does. This work was supported in part by research grants CA124585 and CA138502 from NIH-NCI.

The applying of dual-view DTS technique provides better image quality and spatial resolution in chest imaging.

Zhong, Y, Lai, C, Shen, Y, Shaw, C, Improvement on Chest Digital Tomosynthesis Using Dual-view Geometry.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044495.html