AWS HealthImaging pixel data verification - AWS HealthImaging

AWS HealthImaging pixel data verification

AWS HealthImaging provides built-in pixel data verification by checking the lossless encoding and decoding state of every image.

  • The image onboarding process begins when an import job captures the original pixel quality state of the images before they are imported. A unique immutable Image Frame Resolution Checksum (IFRC) is generated for each image using the CRC32 algorithm.

  • The IFRC is calculated per resolution level for each image frame. The checksum values are present in the metadata document in a list sorted from base to full resolution.

  • After the images are imported, they are immediately decoded and new IFRCs are calculated. HealthImaging compares the full resolution IFRCs of the original images against the new IFRCs of the imported images to verify accuracy.

  • A corresponding per-image descriptive error condition is captured in the import job output log for you to review and verify.

To verify pixel data
  1. After importing your medical imaging data, view the per-image set descriptive success (or error condition) captured in the import job output log, job-output-manifest.json. For more information about job-output-manifest.json, see Understanding import jobs.

  2. Fetch the relevant metadata for the image set using the GetImageSetMetadata action. For more information, see Getting image set metadata.

    The metadata for the image set contains information about the image frame (pixel data). The PixelDataChecksumFromBaseToFullResolution contains the IFRC (checksum) per resolution level. Following is example metadata output for the IFRC that is generated as part of the import job process.

    "ImageFrames": [{ "ID": "67890678906789012345123451234512", "PixelDataChecksumFromBaseToFullResolution": [ { "Width": 128, "Height": 128, "Checksum": 2928338830 }, { "Width": 256, "Height": 256, "Checksum": 1362274918 }, { "Width": 512, "Height": 512, "Checksum": 2510355201 } ]
  3. To verify pixel data, access the Pixel data verification procedure on GitHub and follow the instructions in the README.md file to independently verify lossless image processing by the various HTJ2K decoding libraries that are utilized by HealthImaging. As data is progressively loaded per resolution level, you can compute the IFRC for raw input data on your end and compare it with the IFRC value provided in the HealthImaging metadata for that same resolution to verify the pixel data.