On breast MRI, a 15 mm lesion in the left breast shows rapid initial enhancement followed by washout kinetics (type III curve). Which characteristic best indicates malignancy on dynamic contrast-enhanced MRI (DCE-MRI)?

• A Type I (persistent) enhancement kinetics
• B Type II (plateau) enhancement kinetics
• C Slow initial enhancement with persistent late phase
• D Type III (washout) enhancement kinetics ✓

Explanation

On DCE-MRI, enhancement kinetics are described by initial phase (rate of uptake in first 2 minutes) and delayed phase pattern. Type III (washout) — rapid initial enhancement >100% followed by signal decrease in delayed phase — has the highest association with malignancy (sensitivity ~90%). Type I (persistent) is most often benign. Type II (plateau) is indeterminate. Morphological features (irregular shape, spiculated margins, rim enhancement) combined with type III kinetics increase specificity significantly. BI-RADS MRI 5 warrants biopsy.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.