Breast Biopsies Under Magnetic Resonance Imaging Guidance: Challenges of an Essential but Imperfect Technique.

Magnetic resonance imaging (MRI)-guided breast biopsy is an essential tool of a breast imager; yet, a decade after its introduction, this technique remains challenging and imperfect. This article presents the technique of MRI-guided biopsy, with an emphasis on challenges particular to the technique: technical considerations related to adequate lesion sampling and difficulties in confirming radiologic-pathologic correlation for enhancing lesions. Through clinical vignettes, challenges unique to MRI-guided biopsy are discussed and practical tips are offered. Prebiopsy planning including second-look targeted studies, patient preparation, and equipment is covered. Challenging situations pertaining to breast size, lesion location, or type of enhancement are illustrated, as well as the topic of performing multiple MRI-guided breast biopsies in a single session and biopsies of women with implants. Postbiopsy management is discussed. Success of MRI-guided biopsies requires careful prebiopsy planning, as well as appropriate choice of biopsy device, optimized for the specifics of breast shape and lesion size and location. Special features of biopsy systems (smaller apertures and blunt tips) facilitate the sampling of lesions in challenging locations. Vanishing lesions should undergo short-term follow-up, because malignancy cannot be excluded, as should lesions diagnosed as benign after pathologic analysis when the result is felt to be concordant with imaging features. To this end, radiologic-pathologic correlation is essential. Underestimation rates after MRI-guided breast biopsy are superior to those for vacuum-assisted stereotactic biopsy and ultrasound-guided biopsy. Close follow-up and rebiopsy should be considered when there is imaging-discordant histology. For benign and concordant histology, a first follow-up can be offered at 6 months.