Hi,

I want to modify a single value of a DICOM tag on about 600 GB of DICOM files which are located on a slow network drive. Reading a single DicomAttribute is not touching the PixelData and therefor it is relatively fast but it does not seem to be done the same way when it comes to saving a DICOM file.

I took a look at the source and it looks like the DicomStreamWriter is writing every values not just the values that got modified.

Is this right and if so is there anything I can do to speed up the saving process?

 

kind regards, Martin

Unfortunately, no - DICOM Files pretty much have to be re-written back out. The only way you could possibly get around it is if you knew for sure that the value you were modifying was:

a) already present (e.g. not being added)
b) longer than the value replacing it
c) is ok to pad with spaces

Then, and only then, you could surgically modify the file ...

but I wouldn't recommend it :)