10-15% of MTS is bilateral, if comparison and primary findings of atrophy are used alone the diagnosis may be missed
Secondary findings will help diagnose more cases. They are:
- mamillary body atrophy,
- temporal horn dilation,
- reduced digitations,
- reduced parahippocampal grey-white matter differentiation and
- decreased thickness of collateral white matter
Secondary findings also help to decide the side to be operated for maximal patient benefit.
if all MRI findings and EEG are equivocal, FDG-PET is used.