README.md

Node.js DICOM

The package provides the following:

• Data dictionary according to the 2014a standard.
• Streaming DICOM Decoder that reads a DICOM stream and emits DicomEvent instances.
• Streaming JSON Encoder that turns a DicomEvent stream into a DICOM JSON Model
• JSON Sink that consumes the JSON Model stream and produces an in-memory JSON Object.

Limitations:

• ISO 2022 character sets are not in iconv-lite, this means the decoder does not currently support ISO 2022 encodings, multi-valued (0008,0005) Specific Character Set and DICOM characterset extensions.
• Dicom Elements with a value length above a configurable threshold are not constructed in-memory, but emitted as start_element, a sequence of raw events with the encoded value and an end_element event. The JSON Encoder emits these as bulkdata URLs, but currently there is no way to use these urls (except parsing the url and extracting the bulkdata using offset and length from the url).
• Other DICOM VRs (OB, OW, OF, OD, UN) do not provide a way to interpret the data, i.e. it's just passed on as a byte array, unchanged.

Documentation:

There is documentation for the various pieces in the doc directory. Most notably:

• DICOM Decoder
• DICOM JSON Model Utilities

Examples:

Read a DICOM file, produce JSON Model, and print some data:

dicom = require "dicom"

decoder = dicom.decoder {guess_header: true}
encoder = new dicom.json.JsonEncoder()
sink = new dicom.json.JsonSink (err, json) ->
  if err
    console.log "Error:", err
    process.exit 10
  print_element json, dicom.tags.PatientID
  print_element json, dicom.tags.IssuerOfPatientID
  print_element json, dicom.tags.StudyInstanceUID
  print_element json, dicom.tags.AccessionNumber

print_element = (json, path...) ->
  console.log dicom.json.get_value(json, path...)

require("fs").createReadStream(process.argv[2]).pipe decoder
  .pipe encoder
  .pipe sink

And the same thing in Javascript:

"use strict";

var dicom = require("dicom");

var decoder = dicom.decoder({
    guess_header: true
});

var encoder = new dicom.json.JsonEncoder();

var print_element = function(json, elem) {
    console.log(dicom.json.get_value(json, elem));
};

var sink = new dicom.json.JsonSink(function(err, json) {
    if (err) {
      console.log("Error:", err);
      process.exit(10);
    }
    print_element(json, dicom.tags.PatientID);
    print_element(json, dicom.tags.IssuerOfPatientID);
    print_element(json, dicom.tags.StudyInstanceUID);
    print_element(json, dicom.tags.AccessionNumber);
});

require("fs").createReadStream(process.argv[2]).pipe(decoder).pipe(encoder).pipe(sink);