Wavelet Based Noise Reduction in CT-Images Using Correlation Analysis

Abstract-- The projection data measured in computed tomography (CT) and, consequently, the slices reconstructed from these data are noisy. We present a new wavelet based structurepreserving method for noise reduction in CT-images that can be used in combination with different reconstruction methods. The approach is based on the assumption that data can be decomposed into information and temporally uncorrelated noise. In CT two spatially identical images can be generated by reconstructions from disjoint subsets of projections: using the latest generation dual source CT-scanners one image can be reconstructed from the projections acquired at the first, the other image from the projections acquired at the second detector. For standard CTscanners the two images can be generated by splitting up the set of projections into even and odd numbered projections. The resulting images show the same information but differ with respect to image noise. The analysis of correlations between the wavelet ...

• Type: Journal
• Year: 2008
• Where: TMI
• Authors: Anja Borsdorf, Rainer Raupach, Thomas Flohr, Joachim Hornegger
• Keywords: Image, Noise Reduction, TMI 2008, Wavelet