Medical Physics · 1992 · 181 citations · 0 references
MedicineRadiation OncologyRadiologyDiagnostic ImagingDiagnostic RadiologyTreatment PlanningAttenuation CorrectionComputed TomographyComputed Tomography PhysicsDiagnostic Imaging SystemsMedical ImagingRadiation Treatment PlanningComputed Tomography CalibrationComputed Tomography PhantomsCt Number To Electron Density CalibrationCt Number To Electron Density ConversionHounsfield UnitsImaging-based Treatment PlanningTissue Inhomogeneity CorrectionTissue Inhomogeneity Modeling
In order to correct for tissue heterogeneities on a voxel-by-voxel basis during CT-based treatment planning, the relationship between the correction factor (CF) and the CT number in Hounsfield units (HU) for the scanner in use must be established. Since the relationship between CF and electron density (rho e) of various materials is well documented, the rho e vs HU is required for direct computation of the correction factors by treatment planning computers. A CT phantom with 18 different tissue substitutes has been used to establish the rho e vs HU relationship. A description of the phantom and its contents is given and the calibration of the CT function of the planning computer is discussed.