Image noise and radiation dose using an automatic tube current modulation technique at 64-detector computed tomography: effect of off-center patient position, bowtie filter type, and scan projection radiograph

J Comput Assist Tomogr. 2009 Nov-Dec;33(6):973-7. doi: 10.1097/RCT.0b013e31819d6f6f.


We describe the effect of the off-center position, the bowtie filter type, and the direction of scan projection radiograph on the radiation dose and image noise of 64-detector computed tomographic scans using the automatic tube current modulation technique. On anteroposterior scan projection radiographs, the tube current ratio increased, with an increase in the off-center position of the phantom irrespective of the filter size. On lateral scan projection radiographs, it remained constant with each bowtie filter type regardless of the off-center phantom position.

MeSH terms

  • Adult
  • Artifacts
  • Filtration / instrumentation
  • Humans
  • Male
  • Phantoms, Imaging
  • Posture
  • Radiation Dosage*
  • Radiation Protection / methods
  • Tomography, X-Ray Computed / instrumentation
  • Tomography, X-Ray Computed / methods*