Ffmpeg signed/unsigned pixel formats

In my project, I’m using ffmpeg (cli) to decompress buffers extracted from compressed DICOM images to raw rgb or grayscale or yuv with success.

Dicom is also capable to handle signed pixel values, but I’m wondering how to check if the compressed stream is signed/unsigned and also how to convert unsigned to signed and viceversa.

Is it possible?

I cannot find any documentation about this issue.