Do you really know how to diagnose a partial agenesis of the septi pellucidi? In this case, Elisenda Eixarch walks us through it step by step and shows how a subtle finding completely changes the prognosis. We clearly see: ✅ Communicating anterior horns ✅ Cavum septi pellucidi with partial agenesis of the septi ✅ Normal corpus callosum ✅ Normal orientation of the anterior horns ➡️ When we identify a partial agenesis of the septi pellucidi, the key is to differentiate between: • Isolated form — b