Ternary operators don’t work with nullable value types?

I’ve got the following situation:

DateTime? myDt = (DateTime) row["Column"];

This fails when retrieving a DBNull value, so we check for that:

DateTime? myDT = (row["Column"] == DBNull.Value) ? null : (DateTime) row["Column"];

This won’t compile, however doing:

DateTime? myDT;
if(row["Column"] == DBNull.Value)
myDT = null;
myDT = row["Column"];

works fine, now, I realise I can simplify that statement, but, for the purposes of this post, it is a closer match to the ternary operator.

Why won’t the ternary op work with the value type? It works perfectly with a string…