---
tags: ohif
---
# wadoImageLoad
# getTransferSyntaxForContentType

export function getTransferSyntaxForContentType(contentType) {
  const defaultTransferSyntax = '1.2.840.10008.1.2'; // Default is Implicit Little Endian.

  if (!contentType) {
    return defaultTransferSyntax;
  }

  // Browse through the content type parameters
  const parameters = contentType.split(';');
  const params = {};

  parameters.forEach(parameter => {
    // Look for a transfer-syntax=XXXX pair
    const parameterValues = parameter.split('=');

    if (parameterValues.length !== 2) {
      return;
    }

    const value = parameterValues[1].trim().replace(/"/g, '');

    params[parameterValues[0].trim()] = value;
  });

  // This is useful if the PACS doesn't respond with a syntax
  // in the content type.
  // http://dicom.nema.org/medical/dicom/current/output/chtml/part18/chapter_6.html#table_6.1.1.8-3b
  const defaultTransferSyntaxByType = {
    'image/jpeg': '1.2.840.10008.1.2.4.70',
    'image/x-dicom-rle': '1.2.840.10008.1.2.5',
    'image/x-jls': '1.2.840.10008.1.2.4.80',
    'image/jp2': '1.2.840.10008.1.2.4.90',
    'image/jpx': '1.2.840.10008.1.2.4.92',
  };

  if (params['transfer-syntax']) {
    return params['transfer-syntax'];
  } else if (
    contentType &&
    !Object.keys(params).length &&
    defaultTransferSyntaxByType[contentType]
  ) {
    // dcm4che seems to be reporting the content type as just 'image/jp2'?
    return defaultTransferSyntaxByType[contentType];
  } else if (params.type && defaultTransferSyntaxByType[params.type]) {
    return defaultTransferSyntaxByType[params.type];
  }

  return defaultTransferSyntax;
}