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Proceedings Paper

Effect of maximum likelihood-median processing on the contrast-to-noise ratio in digital chest radiography
Author(s): Alan H. Baydush; Carey E. Floyd
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Paper Abstract

Previously, we have shown that Maximum Likelihood Expectation Maximization (MLEM) can be used to effectively estimate a scatter reduced image in digital chest radiography; however, the MLEM technique is known to increase image noise. A MLEM-median (ML- median) technique has been implemented that follows each MLEM iteration with a 3x3 median filter for noise reduction. Subjective image quality of the scatter reduced ML-median processed image was improved over the original measured image with enhanced visualization of the retrocardiac region and the mediastinum. In both the mediastinum and the lung region, contrast was significantly improved, while percent noise (noise) was only slightly increased over that of the measured image. The contrast-to-percent noise ratio (CNF) in these regions was increased 130 percent, on average. ML-median processing was compared to Bayesian Image Estimation that incorporated a Gibb's prior. CNR for the ML-median technique was increased 16.5 percent and 49.7 percent in the lung and mediastinum regions, respectively, over that of the Bayesian technique. The effect of ML-median processing on resolution was also examined.

Paper Details

Date Published: 11 May 1994
PDF: 7 pages
Proc. SPIE 2167, Medical Imaging 1994: Image Processing, (11 May 1994); doi: 10.1117/12.175093
Show Author Affiliations
Alan H. Baydush, Duke Univ. Medical Ctr. (United States)
Carey E. Floyd, Duke Univ. Medical Ctr. (United States)


Published in SPIE Proceedings Vol. 2167:
Medical Imaging 1994: Image Processing
Murray H. Loew, Editor(s)

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