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Vol.52 No.6 contents | Japanese/English |
 | Full Text of PDF (2555K) Article in Japanese |
- The 25th Lung Cancer Mass Screening Seminar -
Design of Image Reconstruction for Lung Cancer Screening with Low Dose Helical Computed Tomography
Isao Yamaguchi11Department of Radiological Technology, Faculty of Health Sciences, Butsuryo College of Osaka, Japan
Objective. The purpose of this study was to compare the feature of low dose lung CT image with normal dose lung CT image. Moreover, we propose appropriate image reconstruction of low dose lung CT based on the target size of lung cancer CT screening. Methods. The CT test phantom images and the chest phantom images scanned by normal dose and low dose were compared. To reduce the image noise and the artifacts of low dose CT image, reconstruction filters were altered and compared. Modulation transfer functions of each reconstruction filter were measured, and the best reconstruction filter was considered based on the purpose of lung cancer CT screening. Results. Image noises and artifacts were increased in the low dose lung CT images compared to normal dose lung CT image. These image noises and artifacts were present even when the window width is set at 1500. The noise of low dose lung CT image decreased when using a reconstruction filter to obtain about 0.9 responses to 0.5 cycles/mm of spatial frequency in relation to the target size of lung cancer CT screening. Conclusion. In order to generalize low dose scan of lung CT screening, reconstruction filters need to be properly adjusted.
key words: Low dose helical computed tomography (CT), CT screening for lung cancer, Lung CT, Image reconstruction, Reconstruction filter
JJLC 52 (6): 968-976, 2012
