DICOM/HL7/FHIR Interoperability MCP Server

Instructions

Implementation Reference

• src/dicom_hl7_mcp/tools/dicom_tags.py:63-121 (handler)

  The `lookup_dicom_tag` function implementation, which takes a tag string (number or keyword), parses it, and returns a formatted description of the DICOM tag.

  def lookup_dicom_tag(tag: str) -> str:
      """Look up a DICOM tag by group/element number or keyword.
  
      Args:
          tag: Tag identifier. Accepts:
              - Tag number: "0010,0010", "(0010,0010)", "00100010"
              - Keyword: "PatientName", "patient name", "Patient's Name"
  
      Returns:
          Formatted string with tag information.
      """
      # Try parsing as a numeric tag
      parsed = _parse_tag_input(tag)
      if parsed is not None:
          info = DICOM_TAGS.get(parsed)
          if info:
              return _format_tag_result(parsed, info)
  
          # Check if it's in a private tag range
          group, element = parsed
          if group % 2 == 1:  # Odd group = private
              return _format_private_tag_info(group, element)
  
          return (
              f"Tag {format_dicom_tag(*parsed)} not found in the dictionary.\n\n"
              f"This could be:\n"
              f"- A less common standard tag not in our database\n"
              f"- A private tag (odd group numbers are private)\n"
              f"- An incorrect tag number\n\n"
              f"Try searching by keyword instead, or check the DICOM PS3.6 Data Dictionary."
          )
  
      # Try keyword search
      results = _find_by_keyword(tag)
      if not results:
          return (
              f"No DICOM tags found matching '{tag}'.\n\n"
              f"Tips:\n"
              f"- Try a different keyword (e.g., 'patient' instead of 'pt')\n"
              f"- Use the tag number format: '0010,0010'\n"
              f"- Keywords are searched case-insensitively"
          )
  
      if len(results) == 1:
          return _format_tag_result(results[0][0], results[0][1])
  
      # Multiple results
      output_parts = [f"Found {len(results)} tags matching '{tag}':\n"]
      for tag_key, tag_info in results[:15]:  # Limit to 15 results
          retired = " [RETIRED]" if tag_info.get("retired") else ""
          output_parts.append(
              f"  {format_dicom_tag(*tag_key)}  {tag_info['keyword']}  "
              f"VR: {tag_info['vr']}  — {tag_info['name']}{retired}"
          )
  
      if len(results) > 15:
          output_parts.append(f"\n  ... and {len(results) - 15} more. Try a more specific keyword.")
  
      return "\n".join(output_parts)