A medical sub-specialty which utilizes minimally-invasive image-guided procedures to diagnose and treat diseases in nearly every organ system. The concept behind interventional radiology is to diagnose and treat patients using the least invasive techniques currently available. As the inventors of angioplasty and the catheter-delivered stent, interventional radiologists pioneered modern minimally-invasive medicine. Using X-rays, CT, ultrasound, MRI, and other imaging modalities, interventional radiologists are able to obtain images which are then used to direct instruments throughout the body. These procedures are usually performed using needles and narrow tubes called catheters through blood vessels or natural lumens (urethra, colon, oro-pharnynx, trachea), rather than by making large incisions into the body as in traditional surgery. Many conditions that once required surgery can now be treated non-surgically by interventional radiologists. By minimizing the physical trauma to the patient, these interventions can reduce infection rates and recovery time, as well as shorten hospital stays. Interventional radiologists are minimally invasive specialists. The landscape of human and veterinary medicine is constantly changing, and for the past 30 years, interventional radiologists have been responsible for much of the medical innovation and development of the minimally invasive procedures that are commonplace today. Today many conditions, in human and veterinary medicine that once required surgery can be treated non-surgically by interventional radiologists. While no treatment is risk free, the risks of interventional procedures are far lower than the risks of open surgery, and are a major advance in medicine for patients.