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| Multi-energy CT |
| Background and Research Goal |
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Two major techniques that are currently discussed for multi-energy CT are a dual-kVp and dual-layer detector. The main limitations include: (1) there is significant overlap between multiple energy spectra; and (2) it is not practical to increase the number of energy information to 3 or more (Ref. 1 and Pub. 1), both of which result in the limited accuracy of material decomposition. Recently, photon counting detectors, which are capable of counting x-ray photons with energy discriminations, have been developed (Refs. 2-4). These detectors seem to have nice properties. There is virtually no spectrum overlap between energy windows; no electrical noise will be added to datum; all photons are equally weighted.
We want to investigate the property of these detectors, develop
methods to compensate for incomplete performance, and develop method
to accomplish our goals—to improve the contras-to-noise or to reduce
the radiation dose, and to improve the accuracy of material
decomposition.
Figure 4.1: Photon counting detector with multiple energy bins (bottom left) provides the best spectrum separation. |
| Methods |
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To be posted soon. |
| Representative Result |
| To be posted soon. |
| Research Team |
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Katsuyuki Taguchi, Ph.D. (P.I.) Zhihui Sun, M.S. Mengxi Zhang, B.S. |
| Supporting Grant |
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We are seeking for an NIH grant for this project.
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| Publication |
1. Taguchi K, Zhang M, Frey EC, Xu J, Segars WP, Tsui BMW, “Image-domain material decomposition using photon-counting CT,” SPIE Medical Imaging 2007, 6510-07, San Diego, CA, U.S.A.
2. Frey EC, Taguchi K, Kapusta M, et al., “Micro-computed tomography with a photon-counting x-ray detector,” SPIE Medical Imaging 2007, 6510-1R, San Diego, CA, U.S.A.
3. Frey EC, Wang X, Du Y, Taguchi K, Xu J, and Tsui BMW, “Investigation of the use of photon-counting detectors with energy discrimination capability for material decomposition in micro-computed tomography,” SPIE Medical Imaging 2007, 6510-0A, San Diego, CA, U.S.A.
4. Xu J, Frey EC,
Taguchi K, Tsui BMW, “A Poisson likelihood iterative reconstruction
algorithm for material decomposition in CT,” SPIE Medical Imaging 2007,
6510-70, San Diego, CA, U.S.A.
References
1. Kelcz F, Joseph PM, Hilal SK. Noise considerations in dual energy CT scanning. Medical Physics. 1979;6(5):418-25.
2. Tomita Y, Shirayanagi Y, Matsui S, Aoki T, Hatanaka Y. X-ray color scanner with multiple energy discrimination capability. Medical Imaging 2005: Physics of Medical Imaging; 2005; San Diego, CA, USA: SPIE; 2005. p. 59220A.
3. Tomita Y, Shirayanagi Y, Matsui S, Misawa M, Takahashi H, Aoki T, et al. X-ray color scanner with multiple energy differentiate capability. IEEE Nuclear Science Symposium and Medical Imaging Conference; 2004; Roma, Italy: IEEE; 2004.
4. Frey EC, Taguchi K, Kapusta M, Xu J, T. Orskaug, Ninive I, et al. Microcomputed tomography with a photon-counting X-ray detector. Medical Imaging 2007: Physics of Medical Imaging; 2007; San Diego, CA, USA: SPIE; 2007. p. 6510-62.
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