{
  "package" : "hl7.fhir.r4.examples@4.0.1",
  "definition" : "The TG18-GVN Pattern used to assess display veiling. This pattern is identical to AAPM TG18-GV Pattern except that the large-diameter white circle is replaced with a black circle, creating a completely black pattern except for the presence of low-contrast targets. See [AAPM OR 03]",
  "system" : "http://dicom.nema.org/resources/ontology/DCM",
  "property" : [ ],
  "codesystem" : "5f336dd4-db81-5653-939a-25648922f08e",
  "concept_id" : "df59f156-dbd8-580e-8c08-98b3768e3ff2",
  "ancestors" : {
    "109866" : 0
  },
  "id" : "4052014b-f9b7-4816-b979-5811612e1e2d",
  "code" : "109866",
  "display" : "TG18-GVN Pattern",
  "version" : "01"
}