
		<paper>
			<loc>https://jjcit.org/paper/136</loc>
			<title>A HYPER-SURFACE-BASED MODELING AND CORRECTION OF BIAS FIELD IN MR IMAGES</title>
			<doi>10.5455/jjcit.71-1617051919</doi>
			<authors>Daouia Azzouz,Smaine Mazouzi</authors>
			<keywords>MRI data labeling,Bias field correction,EM clustering,4D hyper-surface,Lagrangian interpolation</keywords>
			<citation>2</citation>
			<views>5671</views>
			<downloads>1345</downloads>
			<received_date>29-Mar.-2021</received_date>
			<revised_date>  16-May-2021</revised_date>
			<accepted_date>  25-May-2021</accepted_date>
			<abstract>Dealing  with  the  different  artifacts  in  medical  images  is  necessary  to  perform  several tasks, including 
segmentation. We introduce in this paper a novel method for bias field correction in Magnetic Resonance Imaging 
(MRI). Using the segmentation results obtained by a modified Expectation Maximization clustering, the bias field 
is fitted as a hyper-surface in a 4D hyper-space. Then, it is corrected based on the fact  that voxels belonging to 
the same tissue should have the same intensity in the whole image. So, after a quick and coarse unsupervised voxel 
labeling  by  clustering  by  parts is  performed,  the  bias field  is  computed for reliably  labeled voxels.  For  the  less 
reliably  labeled  voxels, the  bias field  is  interpolated  using  a hyper-surface,  estimated  by  a  4D Lagrangian 
interpolation. We evaluated the  efficiency  of  the  proposed  method by  comparing  segmentation  results with  and 
without  bias field  correction.  Also, we  used the  coefficient  of variation within  the  MRI  volume.  Segmentation 
results  and  the  coefficient  of  variation results  were  significantly  enhanced  after  bias field  correction  by  the 
proposed method.</abstract>
		</paper>


