TY  - JOUR
AU  - Dammers, J.
AU  - Axer, M.
AU  - Gräßel, D.
AU  - Palm, C.
AU  - Zilles, K.
AU  - Amunts, K.
AU  - Pietrzyk, U.
TI  - Signal enhancement in polarized light imaging by means of independent component analysis
JO  - NeuroImage
VL  - 49
SN  - 1053-8119
CY  - Orlando, Fla.
PB  - Academic Press
M1  - PreJuSER-7896
SP  - 1241 - 1248
PY  - 2010
N1  - This work was supported by the Initiative and Networking Fund of the Helmholtz Association within the Helmholtz Alliance on Systems Biology. Moreover, we like to thank Dr. Bernd Sellhaus, MD (Institute of Neuropathology, RWTH Aachen University, Germany). We are grateful to Markus Cremer (Institute of Neuroscience and Medicine, Research Centre Julich, Germany) for excellent technical assistance and the preparation of the histological sections. Mechanical assembly of the polarimeter was done by the workshop of Friedrich-Schiller University of Jena, Germany.
AB  - Polarized light imaging (PLI) enables the evaluation of fiber orientations in histological sections of human postmortem brains, with ultra-high spatial resolution. PLI is based on the birefringent properties of the myelin sheath of nerve fibers. As a result, the polarization state of light propagating through a rotating polarimeter is changed in such a way that the detected signal at each measurement unit of a charged-coupled device (CCD) camera describes a sinusoidal signal. Vectors of the fiber orientation defined by inclination and direction angles can then directly be derived from the optical signals employing PLI analysis. However, noise, light scatter and filter inhomogeneities interfere with the original sinusoidal PLI signals. We here introduce a novel method using independent component analysis (ICA) to decompose the PLI images into statistically independent component maps. After decomposition, gray and white matter structures can clearly be distinguished from noise and other artifacts. The signal enhancement after artifact rejection is quantitatively evaluated in 134 histological whole brain sections. Thus, the primary sinusoidal signals from polarized light imaging can be effectively restored after noise and artifact rejection utilizing ICA. Our method therefore contributes to the analysis of nerve fiber orientation in the human brain within a micrometer scale.
KW  - Artifacts
KW  - Brain: ultrastructure
KW  - Calibration
KW  - Dust
KW  - Humans
KW  - Image Enhancement: methods
KW  - Image Processing, Computer-Assisted: methods
KW  - Light
KW  - Myelin Sheath: ultrastructure
KW  - Nerve Fibers, Myelinated: ultrastructure
KW  - Nerve Fibers, Unmyelinated: ultrastructure
KW  - Optics and Photonics: methods
KW  - Dust (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:19733674
UR  - <Go to ISI:>//WOS:000272808400011
DO  - DOI:10.1016/j.neuroimage.2009.08.059
UR  - https://juser.fz-juelich.de/record/7896
ER  -