ZOUEU T. Jeremie and LOUM Georges Laboratoire d’Instrumentation Image et Spectroscopie ( L2IS ) Institute National Polytechnique Félix Houphouet-Boigny Yamoussoukro address: Cote d’Ivoire Séminaire au LISA, 10 Novembre 2009

 Institut National Polytechnique de Yamoussoukro Séminaire au LISA, 10 Novembre 2009

 TWAS-UNESCO (Third Word Academy of Science), Trieste, Italy  ISP (International Science Programme), Uppsala, Sweden  Atomic Physics Division, Lund University, Sweden Séminaire au LISA, 10 Novembre 2009

 M. Brydegaard, A. Merdosa, S. Svangberg (Atomic Physics Division, Lund University)  Menan Hervé (Laboratory of Parasitology) Séminaire au LISA, 10 Novembre 2009

 Images and Spectroscopy  System Overview  Malaria Parasites  Diagnosis Approach  Principal Component Analysis  K-means clustering method  Conclusion Séminaire au LISA, 10 Novembre 2009

 Using images data for spectroscopy and diagnosis  Selecting specific point or object in images for study  Collecting quantitative spectra from images data  Identification (or detection) of patterns  Grouping points by spectral fingerprint similarities  Etc. Séminaire au LISA, 10 Novembre 2009

Spatial dimension Spectral dimension

 Spatial dimension: P mn is the pixel intensity for m row and n column  Spectral dimension: P mn ( ) is the intensity of pixel of the coordinates m and n, for the wavelength Séminaire au LISA, 10 Novembre 2009

Spatial dimension Spectral dimension Ag21 Séminaire au LISA, 10 Novembre 2009

For each wavelength, we have: Séminaire au LISA, 10 Novembre 2009 Class 1 Class 3 Class 2 Clusterin g

 Achieving spectroscopic images by transforming ordinary images into spectroscopic images data Case of absorbance images : P a =-Log(P t -P b )/(P ref -P b ) P a is an absorption image P t is transmitted image P b is baseline image P ref is reference image Idem for reflection and scattering Séminaire au LISA, 10 Novembre 2009

Light Source Sample Spectrally sensitive detector Séminaire au LISA, 10 Novembre 2009

 Malaria is cause by a intracellular protozoa parasite called plasmodium  When the parasites proliferate into the erythrocytes, the infected RBCs bind to vascular endothelium (cytoadherence) and to the non- infected RBCs (rosetting).  This block the blood flow and leads to high fever, unconsciousness, coma and … Séminaire au LISA, 10 Novembre 2009

There are four types of plasmodium:  Plasmodium falciparum  Plasmodium ovale  Plasmodium vivax  and plasmodium malaria Séminaire au LISA, 10 Novembre 2009

The dangerous and more common (98%) one in Ivory Coast and many African countries is plasmodium falciparum.  The plasmodium falciparum can show about four shapes:  Plasmodium falciparum ring  Plasmodium falciparum trophozoite  Plasmodium falciparum gametocyte  Plasmodium falciparum shizont Séminaire au LISA, 10 Novembre 2009

 Diagnosis: - Cheap equipment - Gain of time and no need of expertise by using not marked RBCs - Make the thin and thick blood smear more sensitive - Automatization of the parasites density and parasite type measurements  Drug-target interaction: - Drug target determination - Parasite survival strategy determination Séminaire au LISA, 10 Novembre 2009

 We choose a voxel V0 of interest  We divide all the voxels of the image by V0  We calculate the standard deviation of each voxels  We build an image of the standard deviation values  We applied a threshold to the standard deviation image (SDI) Séminaire au LISA, 10 Novembre 2009

We consider our type data Séminaire au LISA, 10 Novembre 2009

 9 images taken from 360nm to 1100nm range  Pre-processed images  Quantitative absorption extracted  PCA applied to the images to reduce the dimension  K-means to cluster the pixels of the images Séminaire au LISA, 10 Novembre 2009

 Multispectral Imaging can be used as diagnosis and spectroscopy tool  PCA can be used as correlation tool to add information from each spectral channel for malaria diagnosis and study  K-means can be used to cluster the molecular functions in the image  Quantitative spectra can be used to determine contrast function Séminaire au LISA, 10 Novembre 2009