Radiology is the medical specialty directing medical imaging technologies to diagnose and treat diseases.

Originally, radiology was one component of medical sciences dealing with the medical use of electromagnetic energy emitted through X-ray machines or other such radiation devices for the purpose of obtaining visual information as part of medical imaging.

Radiology involving use of x-ray is called roentgenology. Today, following extensive training, radiologists direct an array of imaging technologies (such as ultrasound, computed tomography(CT) and magneticresonance imaging) to diagnose or treat disease. Interventional radiology is the performance of (usually minimally invasive) medical procedures with the guidance of imaging technologies.

The acquisition of medical imaging is usually carried out by the radiographer or radiologic technologist.

Outside of the medical field, radiology also encompasses the examination of the inner structure of objects using X-rays or other penetrating radiation.