I am using the Pillow fork of PIL and keep receiving the error
OSError: cannot identify image file <_io.BytesIO object at 0x103a47468>
While reading Dicom files the problem might be caused due to Dicom compression. Make sure both gdcm and pydicom are installed.
GDCM is usually the one that's more difficult to install. The latest way to easily install the same is
conda install -U conda-forge gdcm