Sentinel node analysis represents a significant advance in the diagnosis and treatment of invasive breast cancer. The traditional crude method of full axillary dissection for assessing the status of the axillary nodes can now be discarded in favor of the much more elegant and modern approach of minimally invasive sentinel node analysis and its attendant elimination of the morbidity of traditional axillary node dissection. The many impediments to and pitfalls in the technique of sentinel node analysis, however, must be recognized and overcome for the procedure to be reliable and consistently successful. The use of ultrasound and a smaller particle size can help overcome many of these pitfalls. Because ultrasound identification of the axillary sentinel node in patients with invasive breast cancer is possible, it may allow for percutaneous excision of these nodes in the future (Fig. 8). Combining percutaneous excision and ablation of the primary breast carcinoma with percutaneous excision of the sentinel node allows for the nonsurgical treatment of small breast cancers in the future. The modern breast radiologist should be at the forefront of these advances.