Private tags after anonymization

[bobred]

I have a DICOM dataset that I wish to anonymize which I do using the anonymization queue. I have a possible problem with the DICOM RT REG files where a private tag is changed (remove private tags settings false). The original is (3275,1000), VR=LO and value 'Online3D' but when passed through the anonymization queue (3275,1000), VR=unknown and value appears to be Online3d as an ascii array.

I am using the current version.

Any Ideas

[rexcardan]

It has nothing to do with anonymization. It has to do with the format used for writing the DICOM file to bytes. If you use EXPLICIT VR in your DICOM settings, it will write the VR. Otherwise, it just writes the tag, and on reading back, if the tag is not in the Evil DICOM dictionary, it won't know which kind of VR it is. Here is a test that shows you what I mean:

           var dcm = new DICOMObject();
            dcm.Add(new LongString(new Tag("32751000"), "Online3D"));

            var dcmBytes = new byte[0]; //Start empty
            using (var ms = new MemoryStream())
            {
                using (var dw = new DICOMBinaryWriter(ms))
                {
                    //Explicity
                    DICOMObjectWriter.Write(dw, DICOMIOSettings.DefaultExplicit(), dcm);
                }
                dcmBytes = ms.ToArray(); //Store to read back
            }

            var dcmBack = DICOMObject.Read(dcmBytes);
            //This passes
            Assert.IsTrue(dcmBack.FindFirst("32751000").VR == EvilDICOM.Core.Enums.VR.LongString);

            using (var ms = new MemoryStream())
            {
                using (var dw = new DICOMBinaryWriter(ms))
                {
                    //Implicit
                    DICOMObjectWriter.Write(dw, DICOMIOSettings.Default(), dcm);
                }
                dcmBytes = ms.ToArray(); //Store to read back
            }

            dcmBack = DICOMObject.Read(dcmBytes);
            //This fails
            Assert.IsTrue(dcmBack.FindFirst("32751000").VR == EvilDICOM.Core.Enums.VR.LongString);

[bobred]

HiMany thanks, I thought it was something l had missed.Thank you for your time.James

On Thursday, 1 February 2018, 23:04, Rex Cardan <notifications@github.com> wrote:

It has nothing to do with anonymization. It has to do with the format used for writing the DICOM file to bytes. If you use EXPLICIT VR in your DICOM settings, it will write the VR. Otherwise, it just writes the tag, and on reading back, if the tag is not in the Evil DICOM dictionary, it won't know which kind of VR it is. Here is a test that shows you what I mean:` var dcm = new DICOMObject(); dcm.Add(new LongString(new Tag("32751000"), "Online3D")); var dcmBytes = new byte[0]; //Start empty using (var ms = new MemoryStream()) { using (var dw = new DICOMBinaryWriter(ms)) { //Explicity DICOMObjectWriter.Write(dw, DICOMIOSettings.DefaultExplicit(), dcm); } dcmBytes = ms.ToArray(); //Store to read back }

    var dcmBack = DICOMObject.Read(dcmBytes);
    //This passes
    Assert.IsTrue(dcmBack.FindFirst("32751000").VR == EvilDICOM.Core.Enums.VR.LongString);

    using (var ms = new MemoryStream())
    {
        using (var dw = new DICOMBinaryWriter(ms))
        {
            //Implicit
            DICOMObjectWriter.Write(dw, DICOMIOSettings.Default(), dcm);
        }
        dcmBytes = ms.ToArray(); //Store to read back
    }

    dcmBack = DICOMObject.Read(dcmBytes);
    //This fails
    Assert.IsTrue(dcmBack.FindFirst("32751000").VR == EvilDICOM.Core.Enums.VR.LongString);`

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