Keywords:
Spectral CT allows reconstructing a set of material selective basis images which can be used for material quantification. These basis images can be reconstructed independently of each other or treated as a joint reconstruction problem. In this work, we investigate the effect of two ways of introducing coupling between the basis images: using an anti-correlated noise model and regularizing the basis images with a joint prior. We simulate imaging of a FORBILD Head phantom with an ideal photon-counting detector and reconstruct the resulting basis sinograms with and without these two kinds of coupling. The results show that the anti-correlated noise model gives better spatial resolution than the uncorrelated noise model at the same noise level, but also introduces artifacts. If anti-correlations are introduced also in the prior, these artifacts are reduced and the resolution is improved further.
- Mats Persson
- Departments of Bioengineering and Radiology, Stanford University
- Jonas Adler
- KTH Royal Institute of Technology
- T. R. C. Johnson, B. Krauß, M. Sedlmair, M. Grasruck, H. Bruder, D. Morhard, C. Fink, S. Weckbach, M. Lenhard, B. Schmidt, T. Flohr, M. F. Reiser, and C. R. Becker, “Material differentiation by dual energy CT: initial experience,” Eur. Radiol., vol. 17, no. 6, pp. 1510–1517, 2006.
- J. Hsieh, “Dual-energy CT with fast-kVp switch,” Medical Physics, vol. 36, no. 6, pp. 2749–2749, 2009.
- R.Carmi,G.Naveh,andA.Altman,“Materialseparationwithdual-layer CT,” in Nuclear Science Symposium Conference Record, 2005 IEEE, vol. 4, 2005, p. 3.
- K. Taguchi and J. S. Iwanczyk, “Vision 20/20: Single photon counting x-ray detectors in medical imaging,” Med. Phys., vol. 40, no. 10, p. 100901, 2013.
- J. Giersch, D. Niederl¨ohner, and G. Anton, “The influence of energy weighting on x-ray imaging quality,” Nucl. Instrum. Meth. A, vol. 531, no. 1–2, pp. 68 – 74, 2004, proceedings of the 5th International Workshop on Radiation Imaging Detectors.
- P. M. Shikhaliev, “Energy-resolved computed tomography: first experimental results,” Phys. Med. Biol., vol. 53, no. 20, pp. 5595–5613, Oct. 2008.
- J. P. Schlomka, E. Roessl, R. Dorscheid, S. Dill, G. Martens, T. Istel, C. Bumer, C. Herrmann, R. Steadman, G. Zeitler, A. Livne, and R. Proksa, “Experimental feasibility of multi-energy photon-counting Kedge imaging in pre-clinical computed tomography,” Phys. Med. Biol., vol. 53, no. 15, pp. 4031–4047, Aug. 2008.
- J. P. Ronaldson, R. Zainon, N. J. A. Scott, S. P. Gieseg, A. P. Butler, P. H. Butler, and N. G. Anderson, “Toward quantifying the composition of soft tissues by spectral CT with Medipix3,” Med. Phys., vol. 39, no. 11, pp. 6847–6857, 2012.
- M. Persson, R. Bujila, P. Nowik, H. Andersson, L. Kull, J. Andersson, H. Bornefalk, and M. Danielsson, “Upper limits of the photon fluence rate on ct detectors: Case study on a commercial scanner,” Medical Physics, vol. 43, no. 7, pp. 4398–4411, 2016.
- Z. Yu, S. Leng, S. M. Jorgensen, Z. Li, R. Gutjahr, B. Chen, A. F. Halaweish, S. Kappler, L. Yu, E. L. Ritman, and C. H. McCollough, “Evaluation of conventional imaging performance in a research wholebody CT system with a photon-counting detector array,” Phys. Med. Biol., vol. 61, no. 4, p. 1572, 2016.
- R. E. Alvarez and A. Macovski, “Energy-selective reconstructions in x-ray computerised tomography,” Phys. Med. Biol., vol. 21, no. 5, pp. 733–744, Sept. 1976.
- R. F. Barber, E. Y. Sidky, T. G. Schmidt, and X. Pan, “An algorithm for constrained one-step inversion of spectral CT data,” Physics in Medicine and Biology, vol. 61, no. 10, p. 3784, 2016.
- Y. Long and J. A. Fessler, “Multi-material decomposition using statisticalimagereconstructionforspectralCT,”IEEETransactionsonMedical Imaging, vol. 33, no. 8, pp. 1614–1626, Aug 2014.
- E. Roessl and R. Proksa, “K-edge imaging in x-ray computed tomography using multi-bin photon counting detectors,” Phys. Med. Biol., vol. 52, no. 15, p. 4679, 2007.
- H. Gao, H. Yu, S. Osher, and G. Wang, “Multi-energy CT based on a prior rank, intensity and sparsity model (PRISM),” Inverse Problems, vol. 27, no. 11, p. 115012, 2011.
- D. S. Rigie and P. J. L. Rivi`ere, “Joint reconstruction of multi-channel, spectral CT data via constrained total nuclear variation minimization,” Physics in Medicine and Biology, vol. 60, no. 5, p. 1741, 2015.
- C. Schirra, E. Roessl, T. Koehler, B. Brendel, A. Thran, D. Pan, M. Anastasio, and R. Proksa, “Statistical reconstruction of material decomposed data in spectral CT,” Medical Imaging, IEEE Transactions on, vol. 32, no. 7, pp. 1249–1257, July 2013.
- R. Zhang, J. B. Thibault, C. A. Bouman, K. D. Sauer, and J. Hsieh, “Model-based iterative reconstruction for dual-energy x-ray CT using a joint quadratic likelihood model,” IEEE Transactions on Medical Imaging, vol. 33, no. 1, pp. 117–134, Jan 2014.
- A. Sawatzky, Q. Xu, C. Schirra, and M. Anastasio, “Proximal ADMM for multi-channel image reconstruction in spectral x-ray CT,” Medical Imaging, IEEE Transactions on, vol. 33, no. 8, pp. 1657–1668, Aug 2014.
- K. M. Brown, S. Zabi´c, and G. Shechter, “Impact of spectral separation in dual-energy CT with anti-correlated statistical reconstruction,” Proceedings of The thirteenth International Meeting on Fully ThreeDimensional Image Reconstruction in Radiology and Nuclear Medicine, Newport, RI,USA, 2015.
- M. Persson and F. Gr¨onberg, “Spatial-frequency-domain study of anticorrelated noise reduction in spectral CT,” in Proc. 4th Intl. Mtg. on image formation in X-ray CT, 2016, pp. 283–6.
- D. Zeng, Z. Bian, C. Gong, J. Huang, J. He, H. Zhang, L. Lu, Q. Feng, Z. Liang, and J. Ma, “Iterative image reconstruction for multienergy computed tomography via structure tensor total variation regularization,” pp. 978349–978349–9, 2016.
- W. Huh and J. A. Fessler, “Iterative image reconstruction for dual-energy X-ray CT using regularized material sinogram estimates,” in 2011 IEEE International Symposium on Biomedical Imaging: From Nano to Macro, March 2011, pp. 1512–1515.
- G. Lauritsch and H. Bruder, “FORBILD head phantom.” [Online]. Available: http://www.imp.uni-erlangen.de/forbild/english/results/head/ head.html
- M. J. Berger, J. H. Hubbell, S. M. Seltzer, J. Chang, J. S. Coursey, R. Sukumar, D. S. Zucker, and K. Olsen, “XCOM: Photon Cross Section Database,” http://physics.nist.gov/xcom. National Institute of Standards and Technology, Gaithersburg, MD, 2005.
- Tissue substitutes in Radiation Dosimetry and Measurement (report 44). International Commission on Radiation Units and Measurements, Bethesda, MD, 1989.
- K.Cranley,B.J.Gilmore,G.W.A.Fogarty,L.Desponds,andD.Sutton. (1997) IPEM report 78: Catalogue of diagnostic x-ray spectra and other data, electronic version. York: IPEM.
- E. Roessl and C. Herrmann, “Cram´er-Rao lower bound of basis image noise in multiple-energy x-ray imaging,” Physics in Medicine and Biology, vol. 54, no. 5, p. 1307, 2009.
- J. Duran, M. Moeller, C. Sbert, and D. Cremers, “Collaborative total variation: A general framework for vectorial TV models,” SIAM Journal on Imaging Sciences, vol. 9, no. 1, pp. 116–151, 2016.
- J. A. Fessler, “Grouped coordinate descent algorithms for robust edgepreserving image restoration,” Proc. SPIE, vol. 3170, pp. 184–194, 1997.
- D. C. Liu and J. Nocedal, “On the limited memory BFGS method for large scale optimization.” Math. Program., vol. 45, no. 1-3, pp. 503–528, 1989.