Simultaneous Reconstruction of Activity and Attenuation in Time-of-Flight PET

In positron emission tomography (PET) and single photon emission tomography (SPECT), attenuation correction is necessary for quantitative reconstruction of the tracer distribution. Previously, several attempts have been undertaken to estimate the attenuation coefficients from emission data only. These attempts had limited success, because the problem does not have a unique solution, and severe and persistent “cross-talk” between the estimated activity and attenuation distributions was observed. In this paper, we show that the availability of TOF-information eliminates the cross-talk problem by destroying symmetries in the associated Fisher information matrix. We propose a maximum-a-posteriori reconstruction algorithm for jointly estimating the attenuation and activity distributions from TOF-PET data. The performance of the algorithm is studied with 2D simulations, and further illustrated with phantom experiments and with a patient scan. The estimated attenuation image is robust to noise, and does not suffer from the cross-talk that was observed in non-TOF PET. However, some constraining is still mandatory, because the TOF-data determine the attenuation sinogram only up to a constant offset.

[1]  Til Aach,et al.  Simultaneous Reconstruction of Activity and Attenuation for PET/MR , 2011, IEEE Transactions on Medical Imaging.

[2]  Jeffrey A. Fessler,et al.  Spatial resolution properties of penalized-likelihood image reconstruction: space-invariant tomographs , 1996, IEEE Trans. Image Process..

[3]  James E. Bowsher,et al.  An EM algorithm for estimating SPECT emission and transmission parameters from emission data only , 2001, IEEE Transactions on Medical Imaging.

[4]  Johan Nuyts,et al.  Completion of a truncated attenuation image from the attenuated PET emission data , 2013, IEEE Nuclear Science Symposuim & Medical Imaging Conference.

[5]  Maurizio Conti,et al.  First experimental results of time-of-flight reconstruction on an LSO PET scanner , 2007, Physics in medicine and biology.

[6]  M. Conti.  Why is TOF PET reconstruction a more robust method in the presence of inconsistent data? , 2011, Physics in medicine and biology.

[7]  Kathleen Vunckx,et al.  Fisher information-based evaluation of image quality for time-of-flight PET , 2010, 2007 IEEE Nuclear Science Symposium Conference Record.

[8]  Grant T. Gullberg,et al.  Toward accurate attenuation correction in SPECT without transmission measurements , 1997, IEEE Transactions on Medical Imaging.

[9]  Patrick Dupont,et al.  Simultaneous maximum a posteriori reconstruction of attenuation and activity distributions from emission sinograms , 1999, IEEE Transactions on Medical Imaging.

[10]  Alvaro R. De Pierro,et al.  Activity and attenuation recovery from activity data only in emission computed tomography , 2006 .

[11]  M. Defrise,et al.  Time-of-flight PET data determine the attenuation sinogram up to a constant , 2012, Physics in medicine and biology.

[12]  D. Townsend,et al.  Physical and clinical performance of the mCT time-of-flight PET/CT scanner , 2011, Physics in medicine and biology.

[13]  Paul Kinahan,et al.  Attenuation correction for a combined 3D PET/CT scanner. , 1998, Medical physics.

[14]  Frank Natterer,et al.  Determination of tissue attenuation in emission tomography of optically dense media , 1993 .

[15]  H. Kudo,et al.  A new approach to SPECT attenuation correction without transmission measurements , 2000, 2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149).

[16]  W. Moses.  Time of flight in PET revisited , 2003 .

[17]  L. Shepp,et al.  Maximum Likelihood Reconstruction for Emission Tomography , 1983, IEEE Transactions on Medical Imaging.

[18]  J. Nuyts,et al.  A concave prior penalizing relative differences for maximum-a-posteriori reconstruction in emission tomography , 2000 .

[19]  Vladimir Y. Panin,et al.  A method of attenuation map and emission activity reconstructions from emission data , 1999 .

[20]  Frederic H Fahey,et al.  Data acquisition in PET imaging. , 2002, Journal of nuclear medicine technology.

[21]  J. Karp,et al.  Performance of Philips Gemini TF PET/CT scanner with special consideration for its time-of-flight imaging capabilities. , 2007, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[22]  M. Defrise,et al.  Iterative reconstruction for helical CT: a simulation study. , 1998, Physics in medicine and biology.

[23]  Jeffrey A. Fessler,et al.  Grouped-coordinate ascent algorithms for penalized-likelihood transmission image reconstruction , 1997, IEEE Transactions on Medical Imaging.

[24]  Y. Censor,et al.  A New Approach to the Emission Computerized Tomography Problem: Simultaneous Calculation of Attenuation and Activity Coefficients , 1979, IEEE Transactions on Nuclear Science.

[25]  Michel Defrise,et al.  Image Reconstruction Algorithms in PET , 2005 .

[26]  B. H. Hasegawa,et al.  Attenuation Correction Strategies in Emission Tomography , 2006 .

[27]  J. Bowsher,et al.  A log likelihood based method for recovery of localized defects in PET attenuation-correction images , 2004, IEEE Symposium Conference Record Nuclear Science 2004..

[28]  S. Vandenberghe,et al.  Experimental evaluation of simultaneous emission and transmission imaging using TOF information , 2011, 2011 IEEE Nuclear Science Symposium Conference Record.

[29]  A. V. Bronnikov,et al.  Reconstruction of attenuation map using discrete consistency conditions , 2000, IEEE Transactions on Medical Imaging.

[30]  J. Karp,et al.  Systematic and Distributed Time-of-Flight List Mode PET Reconstruction , 2006, 2006 IEEE Nuclear Science Symposium Conference Record.

[31]  Richard M. Leahy,et al.  Accurate estimation of the fisher information matrix for the PET image reconstruction problem , 2004, IEEE Transactions on Medical Imaging.