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Dual-resolution image reconstruction for region-of-interest CT scan

Title
Dual-resolution image reconstruction for region-of-interest CT scan
Author
권오경
Keywords
Computerized Tomography (CT) and Computed Radiography (CR); Medical-image reconstruction methods and algorithms; computer-aided diagnosis
Issue Date
2014-07
Publisher
IOP PUBLISHING LTD
Citation
JOURNAL OF INSTRUMENTATION, 2014, 9(7)
Abstract
In ordinary CT scan, so called full field-of-view (FFOV) scan, in which the x-ray beam span covers the whole section of the body, a large number of projections are necessary to reconstruct high resolution images. However, excessive x-ray dose is a great concern in FFOV scan. Region-of-interest (ROI) scan is a method to visualize the ROI in high resolution while reducing the x-ray dose. But, ROI scan suffers from bright-band artifacts which may hamper CT-number accuracy. In this study, we propose an image reconstruction method to eliminate the band artifacts in the ROI scan. In addition to the ROI scan with high sampling rate in the view direction, we get FFOV projection data with much lower sampling rate. Then, we reconstruct images in the compressed sensing (CS) framework with dual resolutions, that is, high resolution in the ROI and low resolution outside the ROI. For the dual-resolution image reconstruction, we implemented the dual-CS reconstruction algorithm in which data fidelity and total variation (TV) terms were enforced twice in the framework of adaptive steepest descent projection onto convex sets (ASD-POCS). The proposed method has remarkably reduced the bright-band artifacts at around the ROI boundary, and it has also effectively suppressed the streak artifacts over the entire image. We expect the proposed method can be greatly used for dual-resolution imaging with reducing the radiation dose, artifacts and scan time.
URI
http://iopscience.iop.org/article/10.1088/1748-0221/9/07/C07008/meta
ISSN
1748-0221
DOI
10.1088/1748-0221/9/07/C07008
Appears in Collections:
COLLEGE OF ENGINEERING[S](공과대학) > ELECTRONIC ENGINEERING(융합전자공학부) > Articles
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