title: A hybrid strategy to integrate surface-based and mutual-information-based methods for co-registering brain SPECT and MR images.
abstract: Co-registration of brain SPECT and MR images has been used extensively in clinical applications. The complementary features of two major co-registration methods--surface- and mutual-information-based (MI-based)--motivated us to study a hybrid-based scheme that uses the surface-based method to achieve a quick alignment, followed by the MI-based method for fine tuning. Computer simulations were conducted to evaluate the accuracy and robustness of surface-, MI-, and hybrid-based registration methods by designing different levels of noise and mismatch in the registration experiments. Results demonstrated that the hybrid surface-MI-based scheme outperforms both the surface- and MI-based methods in providing superior accuracy and success rates. Specifically, the translational and rotational errors were no more than 1 mm and 2°, respectively, with consistent success rates over 98%. Besides, the hybrid-based method saved 12-53% of the computation efforts, compared with using the MI-based method alone. We recommend the use of hybrid-based method when the orientational differences between the floating and reference images exceed 10°.
authors.affiliation: Department of Computer Science and Information Engineering, National Cheng Kung University, No 1, Dasyue Rd, East District, Tainan City 70101, Taiwan.
authors.forename: Yuan-Lin
authors.initials: YL
authors.lastname: Liao
authors.forename: Yung-Nien
authors.initials: YN
authors.lastname: Sun
authors.forename: Wan-Yuo
authors.initials: WY
authors.lastname: Guo
authors.forename: Yuan-Hwa
authors.initials: YH
authors.lastname: Chou
authors.forename: Jen-Chuen
authors.initials: JC
authors.lastname: Hsieh
authors.forename: Yu-Te
authors.initials: YT
authors.lastname: Wu
mesh_terms: D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003198:Computer Simulation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*