Can I bring my spouse and children?

Short answer: Not on your student visa. Italian law allows some holders of a residence permit of at least one year, including study permits, to apply later for family reunification if they meet income and housing requirements. The process starts in Italy.

Talk to a patronato or your university's international office about current income and housing thresholds before you plan.
Prepare apostilled marriage and birth certificates in advance (P16).
Budget honestly: a PhD scholarship for a family in a big city is tight.

This page explains official rules in plain language. I am not an immigration adviser and I do not give visa advice. For that, always use official government sources. Rules change: confirm with your university, the embassy and VFS before you act.