Area of a Quadrilateral from Square Midpoints

Square $ABCD$ has side length 12. $P$, $Q$, $R$, and $S$ are the midpoints of $AB$, $BC$, $CD$, and $DA$, respectively. $PS$ and $AQ$ intersect at $T$, and $RS$ and $DQ$ intersect at $U$. What is the area of quadrilateral $QTSU$?