{
  "resourceType": "CodeSystem",
  "id": "npcr-mri-observation-types",
  "url": "https://npcr.se/fhir/CodeSystem/npcr-mri-observation-types",
  "name": "NPCRMRIObservationTypes",
  "title": "NPCR MRI Observation Component Types Code System",
  "status": "draft",
  "experimental": false,
  "description": "NPCR-internal code system identifying the four observation types that together form an MRI findings observation in NPCR Anmälan: prostate volume measured by MRI, highest PI-RADS category, extraprostatic extension likelihood, and seminal vesicle invasion likelihood.\n\nThis CodeSystem is used as the code binding for Observation.component.code in NPCRMRIFindingsObservation, enabling FHIR component slicing discrimination across the four findings collected from a single MRI examination.\n\nRationale: NPCR Informationsspecifikation §7 does not provide terminology bindings for MR findings (contrast with §7.2.2 Prostatavolym where SNOMED CT-SE 249606000 is specified for TRUL measurements). International terminologies such as SNOMED CT and LOINC do contain concepts for PI-RADS, EPE, and SVI, but NPCR documentation does not specify which to use. This NPCR-internal CodeSystem preserves documentation fidelity by mirroring NPCR's Variabelbeskrivning variable structure, avoiding researcher-introduced terminology choices.\n\nThesis Discussion note: Component slicing in FHIR requires a discriminating code value for each component; unlike the main Observation.code (which can be left unbound as resource identification falls back to meta.profile), component.code cannot be left empty because the FHIR validator needs it to distinguish slices. This pragmatic requirement necessitates a code value even when NPCR documentation provides none—a tradeoff between documentation fidelity and FHIR structural constraints.",
  "content": "complete",
  "caseSensitive": true,
  "count": 4,
  "concept": [
    {
      "code": "prostateVolumeMR",
      "display": "Prostate volume measured by MRI",
      "definition": "Volume of the prostate gland determined from MRI (corresponds to NPCR Variabelbeskrivning variable D_VolMR). Unit: ml or cm3."
    },
    {
      "code": "piRads",
      "display": "PI-RADS category (highest)",
      "definition": "Highest Prostate Imaging Reporting and Data System (PI-RADS) assessment category reported in the MRI examination (corresponds to NPCR Variabelbeskrivning variable D_Pirads). Value is bound to NPCRPIRADSCategory."
    },
    {
      "code": "epe",
      "display": "Extraprostatic extension likelihood",
      "definition": "Likelihood that extraprostatic extension is present, on a 5-point scale (corresponds to NPCR Variabelbeskrivning variable D_EPE). Reported only when PI-RADS = 4 or 5. Value is bound to NPCRMRILikelihoodScale."
    },
    {
      "code": "svi",
      "display": "Seminal vesicle invasion likelihood",
      "definition": "Likelihood that seminal vesicle invasion is present, on a 5-point scale (corresponds to NPCR Variabelbeskrivning variable D_SVI). Reported only when PI-RADS = 4 or 5. Value is bound to NPCRMRILikelihoodScale."
    }
  ]
}