This value set includes codes based on the following rules:

• Include these codes as defined in http://dicom.nema.org/resources/ontology/DCM

  Code	Display	Definition
  121206	Distance	A one dimensional, or linear, numeric measurement.
  112031	Attenuation Coefficient	A quantitative numerical statement of the relative attenuation of the X-Ray beam at a specified point. Coefficient that describes the fraction of a beam of X-Rays or gamma rays that is absorbed or scattered per unit thickness of the absorber. This value basically accounts for the number of atoms in a cubic cm volume of material and the probability of a photon being scattered or absorbed from the nucleus or an electron of one of these atoms. Usually expressed in Hounsfield units [referred to as CT Number in Fraser and Pare].
  113981	Water Equivalent Diameter Representative Value	The Water Equivalent Diameter is a value at a single location sufficiently representative of the body region.
  113983	Water Equivalent Diameter From Raw Data	The Water Equivalent Diameter value is derived from Raw Data rather than reconstructed slices.See .
  113982	Water Equivalent Diameter Integrated Across Scan Range	The Water Equivalent Diameter integrates values for a sample of reconstructed slices across the entire scan range.
  111046	Percent Fibroglandular Tissue	Percent of breast area that is mammographically dense, excluding pectoralis muscle.
  128527	Distance Correction	A correction factor for a measurement of distance or location.
  128405	Breast Thickness	Thickness of the breast.
  128526	Tissue Fraction	The amount of a specific tissue content, either mass or volume, in a material.
  128408	Patient AP Dimension	The size of a patient in the anterior-posterior dimension.
  128407	DgN	Normalized Mean Glandular Dose (DgN) is the conversion value used to calculate the absorbed dose from radiation to the fibroglandular tissue component of the breast from the exposure in air.
  128409	Patient Lateral Dimension	The size of a patient in the lateral dimension.
  128453	Curve Fit Parameter	A value used in a mathematical function to create a curve or a function that approximates a set of data.
  128452	Correction Factor	A factor used to make an adjustment to a calculation to account for deviations.
  128411	Backscatter	Scattering of radiation in a direction opposite to that of the incident radiation.
  128433	Tissue Air Ratio	Ratio of the absorbed dose at a given depth in tissue to the absorbed dose at the same point in air.
  128455	Homogeneity Factor	A value used to describe the uniformity or composition of data or a material that relates to the same degree of variability.
  128410	SSDE Conversion Factor	Conversion factor for Size Specific Dose Estimate (SSDE) calculations from CTDIvol.
  128523	Offset Factor	A factor that is used to make an adjustment to a calculation to translate or move the data in a defined manner.
  128522	Normalization Factor	A factor that is used to make an adjustment to a calculation to normalize the data.
  113984	Water Equivalent Diameter From Localizer	The Water Equivalent Diameter value is derived from a Localizer image.See .
  111634	Half Value Layer	Thickness of Aluminum required to reduce the X-Ray output at the patient entrance surface by a factor of two.

• Include these codes as defined in http://ncit.nci.nih.gov

  Code	Display
  C70774	Unit Conversion Factor