Fractional scan algorithms for low-dose perfusion CT

Med Phys. 2004 May;31(5):1254-7. doi: 10.1118/1.1708653.


One of the key considerations in CT perfusion is the X-ray dose received by the patient, since cine acquisition mode is typically used in which repeated x-ray exposure occurs at the same anatomical location. In this technical note, we propose a new approach for dose reduction in which the X-ray tube current is maintained and the number of projection views is reduced per gantry rotation. A projection interpolation algorithm and an image prediction algorithm are developed to address the incompleteness of such projection data. Both algorithms utilize a priori knowledge that the contrast-uptake in perfusion images is gradual and predictable. As a result, excellent perfusion images can be reconstructed at a fraction of the nominal radiation dose.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Brain / diagnostic imaging
  • Contrast Media*
  • Humans
  • Radiation Injuries / prevention & control*
  • Radiation Protection / methods*
  • Radiographic Image Enhancement / methods*
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Tomography, X-Ray Computed / adverse effects*
  • Tomography, X-Ray Computed / methods*


  • Contrast Media