Abstract:
:The x-ray exposure to patients has become a major concern in computed tomography (CT) and minimizing the radiation exposure has been one of the major efforts in the CT field. Due to plenty high-attenuation tissues in the human chest, under low-dose scan protocols, thoracic low-dose CT (LDCT) images tend to be severely degraded by excessive mottled noise and non-stationary streak artifacts. Their removal is rather a challenging task because the streak artifacts with directional prominence are often hard to discriminate from the attenuation information of normal tissues. This paper describes a two-step processing scheme called 'artifact suppressed large-scale nonlocal means' for suppressing both noise and artifacts in thoracic LDCT images. Specific scale and direction properties were exploited to discriminate the noise and artifacts from image structures. Parallel implementation has been introduced to speed up the whole processing by more than 100 times. Phantom and patient CT images were both acquired for evaluation purpose. Comparative qualitative and quantitative analyses were both performed that allows conclusion on the efficacy of our method in improving thoracic LDCT data.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Chen Y,Yang Z,Hu Y,Yang G,Zhu Y,Li Y,Luo L,Chen W,Toumoulin Cdoi
10.1088/0031-9155/57/9/2667subject
Has Abstractpub_date
2012-05-07 00:00:00pages
2667-88issue
9eissn
0031-9155issn
1361-6560journal_volume
57pub_type
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