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Proceedings Paper

Dose saving and scatter reduction in volume-of-interest (VOI) cone beam CT: work in progress
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Paper Abstract

In this study, we investigated the magnitude of scattered radiation and beam quality on the low contrast performance in cone beam breast CT imaging with applying volume-of-interest (VOI) imaging technique. For experiments, we used our bench-top cone beam CT (CBCT) system with a flat-panel digital detector. A cylindrical polycarbonate phantom of 11 cm in diameter was used to simulate breasts to measure radiation dose, scatter-to-primary-ratio (SPR), and contrast-to-noise ratio. To implement the VOI scanning technique, a lead filter with a rectangular opening was placed between the x-ray source and the breast phantom. The x-ray tube voltage setting was 80 kVp. The breast phantom was imaged without and with the VOI filter for open filed and VOI field, respectively. Dose measurement was performed using TLD dosimeters. Slot scanning technique with varying slot width was used to measure SPR values. The image quality assessment was performed based on figure of merit (FOM). The results showed that dose can be reduced by a factor of 3 or more outside the VOI and by a factor of 1.6 at the center of the phantom. The SPR value could be reduced by a factor of 9 inside the VOI, and the FOM was improved by a factor of 1.8 at the center of the phantom.

Paper Details

Date Published: 19 March 2008
PDF: 5 pages
Proc. SPIE 6913, Medical Imaging 2008: Physics of Medical Imaging, 69134V (19 March 2008); doi: 10.1117/12.772807
Show Author Affiliations
Chao-Jen Lai, The Univ. of Texas M.D. Anderson Cancer Ctr. (United States)
Chris C. Shaw, The Univ. of Texas M.D. Anderson Cancer Ctr. (United States)
Lingyun Chen, The Univ. of Texas M.D. Anderson Cancer Ctr. (United States)
Xinming Liu, The Univ. of Texas M.D. Anderson Cancer Ctr. (United States)
Tao Han, The Univ. of Texas M.D. Anderson Cancer Ctr. (United States)
Tianpeng Wang, The Univ. of Texas M.D. Anderson Cancer Ctr. (United States)


Published in SPIE Proceedings Vol. 6913:
Medical Imaging 2008: Physics of Medical Imaging
Jiang Hsieh; Ehsan Samei, Editor(s)

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