Alfred Hero - Interests in Tomographic Imaging

I am principally interested in tomographic reconstruction for noise limited imaging modalities such as emission computed tomography (ECT), a modality which includes positron emission tomography (PET), single photon emission computed tomography (SPECT), and a new modality Compton SPECT. My activities in this and other tomographic areas have included statistical performance prediction and system optimization using Shannon's mutual information measure and generalizations of the Cramer-Rao bound; parametric shape modeling for object boundaries in ECT and NMR (nuclear magnetic resonance) imaging; image confidence region estimation based on projections; maximum likelihood image reconstruction via the EM algorithm and its variations. Some articles which I have recently co-authored appear below.

Journal Articles

  • S. Ahn, J.A. Fessler, D. Blatt, and A. Hero, "Convergent incremental optimization transfer algorithms: application to tomography", (.pdf) , submitted to IEEE Trans. on Medical Imaging, Oct. 2004.

  • A. C. Sauve, A. O. Hero, W. L. Rogers, S. Wilderman and N. H. Clinthorne, ``3D reconstruction for a Compton SPECT camera model" IEEE Trans. on Nuclear Science, Vol. 46, No. 6, pp. 2075-2084, Nov. 1999. IEEE Explore reprint (.pdf) .

  • A O Hero, R Piramuthu, S R Titus, J A Fessler, Minimax emission computed tomography using high resolution anatomical side information and B-spline models. IEEE Tr. Info. Theory, 45(3):920-38, Apr. 1999. IEEE Explore reprint (.pdf) .

  • A O Hero, M Usman, A C Sauve, J A Fessler, Recursive algorithms for computing the Cramer-Rao bound. IEEE Tr. Sig. Proc., 45(3):803-7, Mar. 1997. (IEEE Explore version)

  • A. O. Hero, J. A. Fessler and M. Usman, "Exploring estimator bias-variance tradeoffs using the uniform CR bound" (Sec. II.C typos corrected) (.ps.Z) , IEEE Transactions on Signal Processing, Vol. 44, No. 8, pp. 2026-2042, Aug. 1996. (received 1998 Best Paper Award, IEEE Signal Processing Society) Errata: The lines 4) Compute the point (delta, B(theta, delta)) via B(theta, delta) = lamda^2 * xbar' * Fy * xbar should read B(theta, delta) = lamda^2 * ybar' * Fy * ybar on p. 2030

  • J A Fessler, A O Hero, Penalized maximum-likelihood image reconstruction using space-alternating generalized EM algorithms. IEEE Tr. Im. Proc., 4(10):1417-29, Oct. 1995. (IEEE Explore version)
    Errata: The powers of 2 in the triangle inequalities on p.\ 1427 should not be there. Condition 2 should also include the requirement that \nabla^{10}\phi be continuous in \emph{both} arguments, i.e. in R_S \times R^p There should not be any 1/2 in the definition of J on p.\ 1426. The plus before the final quadratic form in (38) should be a minus.

  • A O Hero, J A Fessler, A recursive algorithm for computing Cramer-Rao-type bounds on estimator covariance. (IEEE Explore) IEEE Tr. Info. Theory, 40(4):1205-10, Jul. 1994.

  • J A Fessler, A O Hero, Space-alternating generalized expectation-maximization algorithm. IEEE Tr. Sig. Proc., 42(10):2664-77, Oct. 1994. (IEEE Explore version)
    Errata: The equation immediately below eqn. (18) is unnecessary. As written it suggests we foolishly replace some of the pixel estimates with "old" values, when of course we do not. The newer version that appears in our 1995 T-IP paper is correct, and supersedes the T-SP version. The proof of Theorem 2 incorrectly states that the eigenvalues of the Gauss-Siedel matrix are real. They can be complex, so the proof only applies to cases where the maximimum magnitude eigenvalue is real.

  • Ping-Chun Chiao; Rogers, W.L.; Fessler, J.A.; Clinthorne, N.H.; Hero, A.O.,
    "Model-based estimation with boundary side information or boundary regularization [cardiac emission CT]," IEEE Trans. on Medical Imaging , Vol. MI-13, No. 2, pp. 227-234, June 1994. IEEE Explore reprint (.pdf) .

  • Ping-Chun Chiao; Rogers, W.L.; Fessler, J.A.; Clinthorne, N.H.; Hero, A.O.,
    "Model-based estimation for dynamic cardiac studies using ECT," IEEE Trans. on Medical Imaging , Vol. MI-13, No. 2, pp. 217-226, June 1994. IEEE Explore reprint (.pdf) .

  • A.O. Hero and L. Shao
    "Information analysis of single photon computed tomography with count losses," IEEE Trans. on Medical Imaging , Vol. MI-9, No. 3, pp. 117-127, June 1990. IEEE Explore reprint (.pdf) .

  • L. Shao, A.O. Hero, W.L. Rogers, N.H. Clinthorne
    "Information gain from count corrections in SPECT image reconstruction and classification," IEEE Trans. on Nuclear Science, Vol. NS-37, No. 2, pp. 652-657, April 1990. IEEE Explore reprint (.pdf) .

  • L. Shao, A.O. Hero, W.L. Rogers, and N.H. Clinthorne
    "The mutual information criterion for the design and evaluation of SPECT apertures," IEEE Trans. on Medical Imaging, Vol. MI-8, pp. 322-336, Dec. 1989. IEEE Explore reprint (.pdf) .

  • N.H. Clinthorne, W.L. Rogers, L. Shao, A.O. Hero and K.F. Koral
    "Application of the mutual information criterion to assessing gamma cameras," IEEE Trans. on Nuclear Science , Vol. NS-36, pp. 1127-1131, Feb. 1989.
    Conference Proceeedings

  • S. Ahn, J.A. Fessler, D. Blatt, and A. Hero, "Incremental optimization transfer algorithms: application to transmission tomography", (.pdf) , submitted to IEEE Conf on Medical Imaging, 2005.

  • T. Kragh and A. O. Hero "Emission tomography from compressed data", (.pdf) Proc. Asilomar Conf. on Signals, Systems and Computers, Pacific Grove, Nov 2002.

  • A. Hero, A. Sauve amd T. Kragh Image reconstruction for a novel Compton scatter tomograph (.ps) , Proc. of IEEE Asilomar Conference on Sig, Syst., and Comm.,, Pacific Grove CA, Oct. 2000. Oct. 2000.

  • T, Kragh, A. Hero, N. Clinthorne, Bias-resolution-variance tradeoffs for single pixel estimation tasks using the Uniform Cramer Rao Bound UCRB , Proc. of IEEE Nuclear Science Symposium, Lyon France, Oct. 2000.

  • A.O. Hero and R. Piramuthu "A method for ECT image reconstruction with uncertain MRI side information using asymptotic marginalization," Proceedings of IEEE/EURASIP Workshop on Nonlinear Signal and Image Processing , Sept. 1997.

  • A. Sauve, A. O. Hero and W. L. Rogers, ``System modeling and spatial sampling techniques for simplification of transition matrix in 3D Electronically Collimated SPECT,'' 1997 International Meeting on Fully 3-Dimensional Image Reconstruction in Radiology and Nuclear Medicine , Pittsburg, June 1997.

  • S. Titus, A. O. Hero and J. A. Fessler, "Penalized likelihood emission image reconstructon with uncertain boundary information" , Proceedings of 1997 IEEE Int. Conf. on Acoust., Speech, and Sig. Proc., Munich, April 1997.

  • A. O. Hero, Y. Zhang and W.L. Rogers, "Tomographic feature detection and classification using parallelotope bounded error estimation," Proceedings of 1997 IEEE Int. Conf. on Acoust., Speech, and Sig. Proc., Munich, April 1997. .pdf

  • S. Titus, A. O. Hero and J. A. Fessler, "Improved penalized likelihood reconstruction of anatomically correlated emission data" , Proceedings of 1996 IEEE Conf. on Image Processing (ICIP), Laussane, Sept. 1996.

  • M. Usman, A.O. Hero and J. A. Fessler
    "Uniform CR bound: implementation issues and applications to image reconstruction," Proceedings of the IEEE 1994 Nuclear Science Symposium and Medical Imaging Conference , Norfolk, Oct. 1994.

  • M. Usman, A.O. Hero and J. A. Fessler
    "Bias-variance tradeoffs analysis using uniform CR bound for images" Proceedings of the 1994 IEEE Conference on Image Processing , Austin, pp. 835-839, Nov. 1994.

  • Y. Zhang, A.O. Hero, and W.L. Rogers "Simultaneous confidence intervals for image reconstruction problems," Proceedings of the IEEE 1994 International Conference on Acoustics, Speech and Signal Processing, Adelaide, Australia, pp. V.317-320, April 1994. .pdf

  • J.A. Fessler and A.O. Hero
    "New complete-data spaces and faster algorithms for penalized-likelihood emission tomography," Proceedings of the IEEE Nuclear Science Symposium and Medical Imaging Conference, San Francisco, pp. 1897-1901, Nov. 1993.

  • M. Usman, A.O. Hero, J.A. Fessler and W.L. Rogers
    "Bias-variance tradeoffs analysis using uniform CR bound for a SPECT system," Proceedings of the IEEE Nuclear Science Symposium and Medical Imaging Conference, San Francisco, pp. 1463-1467, Nov. 1993.

  • A.O. Hero, Y. Zhang and W.L. Rogers
    "Consistency set estimation for PET image reconstruction," Proceedings of the 1993 International Conference on Information Science and Systems, pp. 605-610, Johns Hopkins, March 1993.

  • A O Hero, J A Fessler, and W L Rogers.
    "A fast recursive algorithm for computing CR-type bounds for image reconstruction problems," Conf. Rec. of the IEEE Nuc. Sci. Symp. Med. Im. Conf., vol. 2, pp. 1188-1190, 1992.


    Prof. Alfred Hero III
    Dept. of Electrical Engineering and Computer Science
    The University of Michigan
    1301 Beal Avenue
    Ann Arbor, MI 48109-2122
    Tel. (313) 763-0564
    FAX: (313) 763-8041
    WWW: http://www.eecs.umich.edu/~hero/hero.html
    email: