I’ve been told I have a Chiari malformation. Do I actually need surgery?

The decision whether Chiari malformation needs surgery belongs with a neurosurgeon who knows your full clinical picture, not with a radiology report. What a second-opinion radiology report can do is give your neurosurgeon precise measurements and a structured description of the imaging features — tonsillar descent in millimetres, syrinx status, surrounding anatomy — that inform the discussion. Many Chiari I findings are incidental and not progressive; some are clinically significant and benefit from surgery. The imaging is an important input into that conversation but not the decision itself.