Professional society for physicians who specialize in interventional or minimally invasive procedures. SIR is a nonprofit, national scientific organization deeply committed to its mission to improve health and the quality of life through the practice of cardiovascular and interventional radiology. The society promotes education, research, and communication in the field while providing strong leadership in the development of health care policy. Formerly known as the Society of Cardiovascular and Interventional Radiology (SCVIR) .