Locations & Hours | Radiology Services & Procedures | Insurance Info | Policies & Payments Imaging-Guided Biopsy by Stuart H. Caplan, M.D. Radiologists can now use imaging methods such as computerized tomography, ultrasound, and fluoroscopy to biopsy masses and drain fluid collections in your body, procedures, which once required surgery. The radiologist will use one of these image methods to find the mass or fluid collection. The radiologist will then clean your skin with a soap, alcohol, or iodine solution. He or she may then inject a local anesthetic (similar to Novocain, which is used by many dentists) to decrease pain and then make a very small cut in your skin. Again using images for guidance, he or she will then insert a needle into the mass or fluid collection in your body, avoiding other organs and vital structures. If you are having a biopsy, the radiologist will place the needle into the mass several times to obtain pieces of tissue, which can be sent for tests. If you are having drainage of a fluid collection, the radiologist can sometimes remove all of the fluid through the needle. For larger collections, the radiologist will insert a wire through the needle into the fluid collection, remove the needle, and then guide a thin plastic tube called a catheter over the wire into the fluid collection. The radiologist may send some of the fluid for tests. Sometimes the catheter must remain in place for several days to continue draining fluid. Drainages can often be performed without the need for hospital stay. Before your biopsy or drainage your physician may send you to have blood drawn to help make sure that your blood clots properly and that you will not loose too much blood due to the biopsy or drainage.