Issues with DICOM image quality after burnt-in text redaction

[Ezequiel Gioia]

Hi everyone,

I'm working on a project using the Cloud Healthcare API and am running into some challenges with the de-identification functionality for DICOM data. Specifically, I'm trying to de-identify a DICOM burnt-in text redaction, but I'm finding that the quality of the de-identified images decreases significantly.

The configuration I'm using for the de-identify job is to DEIDENTIFY_TAG_CONTENTS and REDACT_SENSITIVE_TEXT.

Has anyone encountered a similar problem or can offer some insight into what might be misconfigured in my request? Any advice on how to improve the quality of the de-identified image would also be greatly appreciated.

Thank you, 
Ezequiel

[Truc Le]

Hello Ezequiel,

Could you please provide the transfer syntax of the source DICOM instance?

If you have a sample file without PHI, you can open a support ticket and attach it here: https://cloud.google.com/support/docs/issue-trackers

Thanks,
Truc

[Ezequiel Gioia]

This is what I found on the original image. Thanks. 

>dcmdump IMG00002.dcm

# Dicom-File-Format

# Dicom-Meta-Information-Header

# Used TransferSyntax: Little Endian Explicit

...

(0002,0010) UI =JPEG2000LosslessOnly                    #  22, 1 TransferSyntaxUID

...

[Truc Le]

Thanks for the details.

You've correctly identified the issue: we have limited support for JPEG Lossless encoding, which is causing the quality degradation.

We are working a fix to enhance our transfer syntax capabilities, which is targeted for release by the end of this year.

Thanks,

Truc

[Ezequiel Gioia]

Thank you, Truc, for your prompt response. I had some bad luck too—the first image I tested happened to be JPEG Lossless encoded. It works well with the other encodings. Also, I found the following  in the documentation that looks related to what you mentioned:

     " Warning: The default transfer-syntax for image/jpeg (JPEG Lossless, 1.2.840.10008.1.2.4.70) is not supported, so if image/jpeg is requested without specifying a transfer syntax, an error will be returned."

https://cloud.google.com/healthcare-api/docs/dicom#dicom_frames