Noise Reduction on Low Tube Voltage CT Images

저관전압 CT영상에서 발생되는 노이즈 제거

  • Received : 2017.02.15
  • Accepted : 2017.02.28
  • Published : 2017.02.28


To reduce the exposure dose in head CT, the use of low tube voltage is required. However, increasing noise may cause errors in the second data processing. In this study, we proposed a method to reduce noise by using low tube voltage. Experimental results show that the noise level is high at 100kVp and lowest at 140 kVp. The dose was lower at 100 kVp and higher at 140 kVp. As a result of applying the wavelet according to the threshold value, the noise value in the wavelet Th30 decreased to 4.51. Using the parameter condition(100 kVp, rotation time 0.5 sec, dose: 40.64 mGy) and the wavelet Th 30, the dose reduction of 65.3% was possible. We believe that applying the proposed method to head CT images will help to patient safety and interpret accurate information.


Brain CT;Threshold;Noise;Dose


  1. M. Y. Kim, H. S. Kim, "The Evaluation of Radiation Dose by Exposure Method in Digital Magnification Mammography", JRST, Vol. 35, No. 4, pp. 293-298, 2012.
  2. S. Obenauer, K. P. Hermann and E Grabbe, "Dose reduction in full-field digital mammography: an anthropomorphic breast phantom study", Br J Radiol, Vol.76, No. 907, pp. 478-82, 2003
  3. I. J. Lee, "Relationship of Compressed Breast Thickness and Average Glandular Dose According to Focus /Filter", JRST, Vol. 32, No. 3, pp. 261-270, 2009
  4. J. Cho, H. Kang, H. Kim, S. Kim. Mulimedia Signal processing, SciTech media, 2006.
  5. R.Gonzale, R. E.Woods . Image processing, Green, Seoul, 2003.
  6. H. S. Cho, H. Lee, "Choise of Wavelet-Thresholds for Denoising images", The KIPS Transactionsty, Vol. 8, No. 2, pp. 693-698, 2001.
  7. M. B. Williams, P. Raghunathan, M. J. More, J. A. Seibert, A. Kwa, J. Y. Lo, E. Samei, N. T.Ranger, and L. L. Fajardo, L.L. "Optimization of exposure parameters in full field digital mammography. Med Phys", Vol. 35, pp. 2414-2423, 2008
  8. D. L. Donoho and J. M. Johnstone, "Ideal spatial adaptation via wavelet Shrinkage", Biometrica, Vol. 81, pp. 425-455, 1994.
  9. S. Choi, S. J. Ko, S. S. Kang, "Denoising of Digital Mammography Images Using Wavelet Transform", J KSR, Vol. 7, No. 3, pp. 181-189, 2013.


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