Radiology is the branch or specialty of medicine that deals with the study and application of imaging technology like x-ray and radiation to diagnosing and treating disease.
Radiologists direct an array of imaging technologies (such as ultrasound, Computed Tomography (CT) Computed Axial Tomography, Nuclear Medicine, Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI)) 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 radio logic technologist.
Outside of the medical field, Radiology also encompasses the examination of the inner structure of objects using X-rays or other penetrating radiation.
Magnetic Resonance Imaging (MRI), or nuclear magnetic resonance imaging (NMRI), is primarily a medical imaging technique most commonly used in radiology to visualize the internal structure and function of the body. MRI provides much greater contrast between the different soft tissues of the body than computed tomography (CT) does, making it especially useful in neurological (brain), musculoskeletal, cardiovascular, and oncological (cancer) imaging. Unlike CT, it uses no ionizing radiation, but uses a powerful magnetic field to align the nuclear magnetization of (usually) hydrogen atoms in water in the body. Radio frequency (RF) fields are used to systematically alter the alignment of this magnetization, causing the hydrogen nuclei to produce a rotating magnetic field detectable by the scanner. This signal can be manipulated by additional magnetic fields to build up enough information to construct an image of the body.