• 2 sets of descriptors describe kinetic enhancement on breast MR imaging: initial rise and delayed phase generated from multiple time points following injection of contrast

(1) Initial phase (first 2 min; 1st postcon compared to noncon as a % signal increase)

• • Slow (<50% increase in SI; least suspicious)

  • Medium (50-100% increase in SI)

  • Fast (>100% increase in SI; most suspicious)

(2) Delayed phase (after 2 min)

• • Type 1 / Persistent (>10% increase in SI over time): continuous increase in SI over time.

  • Type 2 / Plateau (no change in signal - flat curve): flat curve after initial increase.

  • Type 3 / Washout (>10% decrease in SI over time): initial increase then decrease.