Optimized scanning conditions of high resolution CT in the follow-up of pulmonary emphysema

J Comput Assist Tomogr. May-Jun 1999;23(3):380-4. doi: 10.1097/00004728-199905000-00011.


Purpose: To address the optimal scanning condition of high resolution computerized tomography from the perspective of minimizing exposed dose.

Method: The influence of the electric current, the slice number, and the slice thickness on precise percent ratio of the low attenuation area to whole lung field (LAA%) of chronic obstructive pulmonary disease patients was examined. The standard conditions were 250 mA, 3 slices, 2 mm slice thickness, and a varied parameter.

Results: In cases showing an LAA% less than 30, LAA% obtained by < or =150 mA were significantly larger than those by 250 mA. The mean LAA% with 3 and 10 slices were well correlated and the correlation with lung function was similar. The correlation of LAA% with lung function was approximately the same between the 2 and 5 mm slice thicknesses.

Conclusion: The electrical current must be > or =200 mA, and 3 slices and 2 mm slice thickness are appropriate.

Publication types

  • Clinical Trial

MeSH terms

  • Electricity
  • Follow-Up Studies
  • Humans
  • Pulmonary Emphysema / diagnostic imaging*
  • Pulmonary Emphysema / pathology
  • Radiation Dosage
  • Tomography, X-Ray Computed / adverse effects*
  • Tomography, X-Ray Computed / instrumentation