Interventional radiology is a sub-specialty of radiology in which minimally invasive procedures are performed using image guidance. Some of these procedures are done for purely diagnostic purposes, such as myelograms and arthrograms, while others are done for treatment purposes, such as kyphoplasty. The images are used to direct these procedures, which are usually done with needles or other tiny instruments such as catheters. The images provide road maps that allow the Interventional Radiologist to guide these instruments through the body to the areas of interest.