Most Dicom Readers breaker image
(Philips MR intera, comming from an ViewForum-burned CDROM)
Within an 'Explicit VR' private DICOM Sequence (the length or which is *not
0xffffffff), the Endianness switches from Little Endian to Big Endian, and then
back to Little Endian.
We have to guess the endianness looking at the 'delimitors'
(whether they start with 0xfffe or 0xfeff)