What are the next steps after characterizing abnormal enhancement on breast MRI?
Indeterminate enhancement requires follow-up (BI-RADS 3) or tissue diagnosis (BI-RADS 4). The criteria for follow-up are beyond the scope of this chapter. If tissue diagnosis is needed, careful attention should be paid to any concurrent imaging study such as a mammogram to see if the biopsy can be performed with another modality to reduce costs to the patient and also eliminate the need for a contrast injection. Masses often warrant MRI-directed US to see if the biopsy can be performed under ultrasound guidance. If neither of these other approaches is possible, then MRI-guided percutaneous core biopsy or wire localization for surgical excision is indicated.