Abstract
In this work, we propose to tackle the problem of magnetic resonance (MR)-based radiotherapy treatment planning in the head & neck area by synthesising computed tomography (CT) from MR images using an iterative multi-atlas approach. The proposed method relies on pre-acquired pairs of non-rigidly aligned T2-weighted MRI and CT images of the neck. To synthesise a pseudo CT, all the MRIs in the database are first registered to the target MRI using a robust affine followed by a deformable registration. An initial pseudo CT is obtained by fusing the mapped atlases according to their morphological similarity to the target. This initial pseudo CT is then combined with the target MR image in order to improve both the registration and fusion stages and refine the synthesis in the bone region.
Results showed that the proposed iterative CT synthesis algorithm is able to generate pseudo CT images in a challenging region for registration algorithms. We demonstrate that the robust affine decreases the overall absolute error compared to a single affine transformation, mainly in images with small axial field-of-view, whilst the bone refinement process further reduces the error in the bone region, increasing image sharpness.
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Keywords
- Compute Tomogra Image
- Planning Target Volume
- Mean Absolute Error
- Magnetic Resonance Imaging Intensity
- Atlas Image
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
References
Jonsson, J., Akhtari, M., Karlsson, M., Johansson, A., Asklund, T., Nyholm, T.: Accuracy of inverse treatment planning on substitute CT images derived from MR data for brain lesions. Radiation Oncology 10(1) (2015)
Korhonen, J., Kapanen, M., Keyriläinen, J., Seppälä, T., Tenhunen, M.: A dual model HU conversion from MRI intensity values within and outside of bone segment for MRI-based radiotherapy treatment planning of prostate cancer. Medical Physics 41(1), 011704 (2014)
Dowling, J.A., Lambert, J., Parker, J., Salvado, O., Fripp, J., Capp, A., Wratten, C., Denham, J.W., Greer, P.B.: An atlas-based electron density mapping method for magnetic resonance imaging (MRI)-alone treatment planning and adaptive MRI-based prostate radiation therapy. International Journal of Radiation Oncology · Biology · Physics 83(1), e5–e11 (2012)
Sjölund, J., Forsberg, D., Andersson, M., Knutsson, H.: Generating patient specific pseudo-CT of the head from MR using atlas-based regression. Physics in Medicine and Biology 60(2), 825 (2015)
Gudur, M.S.R., Hara, W., Le, Q.-T., Wang, L., Xing, L., Li, R.: A unifying probabilistic Bayesian approach to derive electron density from MRI for radiation therapy treatment planning. Physics in Medicine and Biology 59(21), 6595 (2014)
Uh, J., Merchant, T.E., Li, Y., Li, X., Hua, C.: MRI-based treatment planning with pseudo CT generated through atlas registration. Med. Phys. 41(5) (2014)
Burgos, N., Cardoso, M.J., Thielemans, K., Modat, M., Pedemonte, S., Dickson, J., Barnes, A., Ahmed, R., Mahoney, C.J., Schott, J.M., Duncan, J.S., Atkinson, D., Arridge, S.R., Hutton, B.F., Ourselin, S.: Attenuation Correction Synthesis for Hybrid PET-MR Scanners: Application to Brain Studies. IEEE Transactions on Medical Imaging 33(12), 2332–2341 (2014)
Modat, M., Ridgway, G.R., Taylor, Z.A., Lehmann, M., Barnes, J., Hawkes, D.J., Fox, N.C., Ourselin, S.: Fast free-form deformation using graphics processing units. Computer Methods and Programs in Biomedicine 98(3), 278–284 (2010)
Modat, M., Cash, D.M., Daga, P., Winston, G.P., Duncan, J.S., Ourselin, S.: Global image registration using a symmetric block-matching approach. Journal of Medical Imaging 1(2), 024003 (2014)
Cachier, P., Bardinet, E., Dormont, D., Pennec, X., Ayache, N.: Iconic feature based nonrigid registration: the PASHA algorithm. Computer Vision and Image Understanding 89(2-3), 272–298 (2003)
Kristan, M., Pernus, F.: Entropy based measure of camera focus. In: Proc. ERK 2004, pp. 179–182 (2004)
Low, D.A., Harms, W.B., Mutic, S., Purdy, J.A.: A technique for the quantitative evaluation of dose distributions. Medical Physics 25(5), 656–661 (1998)
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Burgos, N. et al. (2015). Robust CT Synthesis for Radiotherapy Planning: Application to the Head and Neck Region. In: Navab, N., Hornegger, J., Wells, W., Frangi, A. (eds) Medical Image Computing and Computer-Assisted Intervention -- MICCAI 2015. MICCAI 2015. Lecture Notes in Computer Science(), vol 9350. Springer, Cham. https://doi.org/10.1007/978-3-319-24571-3_57
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DOI: https://doi.org/10.1007/978-3-319-24571-3_57
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