Attenuation

  • Attenuation is the reduction of the intensity of a radiation beam as it passes through an object. Attenuation depends on the atomic density, the incident object’s atomic number (the absorber), and the energy of the incident photon.
  • Beam geometry describes the shape of the x-ray beam as it leaves the x-ray tube housing and strikes the detectors. As the number of detector rows increases, the beam becomes wider to cover the detector array.
    •  Modern multidetector CT scanners (MDCT) utilize a cone beam during image acquisition. The cone beam is utilized in order to expose the entire row of detectors evenly to radiation.

 

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