Radiology is a medical specialty that uses imaging to diagnose and treat diseases seen within the body. Radiologists use a variety of imaging techniques such as X-ray, ultrasound, computed tomography (CT), nuclear medicine including positron emission tomography (PET), and magnetic resonance imaging (MRI) to diagnose and/or treat diseases. A radiologist is a specially trained doctor who interprets diagnostic imaging to guide the management of disease. If you have an interventional procedure (such as an angiogram or biopsy) a specially trained radiologist called an interventional radiologist will perform the procedure. Radiologists provide a scan report which is then sent to your doctor.