MRI-guided biopsy is used whenan abnormality is not clear with mammography or ultrasound scanning. The radiologist may collect a tissue sample using either fine-needle aspiration (FNA), core needle (CN), vacuum-assisted (VABB) or wire localization.
The fine needle aspiration, rarely used, as it normally cannot distinguish between invasive breast cancer and in situ disease,is performed using a small needle to collect samples.
The core needle biopsy, using a somewhat larger needle, can withdraw small cores of tissue from the abnormal area in the breast. The needle is inserted three to five times to obtain samples, making it more beneficial in determining treatment options if the pathology indicates cancer cells.
In a vacuum-assisted breast biopsy (VABB), pressure is used to pull tissue into the needle without having to withdraw the probe after each sampling. Using this method results in larger samples for pathology.
MRI can also be used during a surgical biopsy through using a wire localization. In this procedure, a surgical biopsy involves removing part or all of the abnormal tissue for examination. The radiologist uses MR imaging to help insert the wire through a hollow needle into the suspicious area of the breast and the wire is used as a guide to the area for biopsy.