Technology#

  • CT Machine: The radiation from this machine is a Fan Beam, and images are stored layer by layer (slices).
  • CBCT Machine: The radiation is emitted as a Cone Beam, and the entire target area is imaged in a single 360-degree rotation.

Quality of Different Tissues#

  • Soft Tissues: CT images have very high accuracy for soft tissues (such as internal organs and tumors), whereas CBCT quality in soft tissue is poor.
  • Hard Tissues: CBCT provides highly detailed accuracy for hard tissues (such as bone and teeth).
  • Radiation Dose: The radiation dose in a CBCT machine is significantly lower than that of a CT scan.

Image Output Format#

  • Common Format: Both machines output images in the standard medical format DICOM (.dcm), which stands for Digital Imaging and Communications in Medicine.

File Structure:#

  • CT image outputs can consist of hundreds of separate, high-volume slices.
  • CBCT images usually consist of a single, integrated 3D file with a smaller file size.

Density Measurement:#

  • CT images use the Hounsfield Unit (HU) to store data for the accurate measurement of tissue density.
  • In CBCT, we only have a relative Grayscale scale available.