Learning about Medical Imaging

Medical imaging is defined as a process used to create images of the human body or parts of it for clinical procedures or medical science. The former pertains to procedures seeking to reveal, diagnose, or examine disease. The latter includes the study of anatomy and physiology, among others. However, it is important to note that when imaging is done on removed organs and tissues, this method is considered a part of pathology.

Known as a discipline under biological imaging, it incorporates radiology, nuclear medicine, investigative radiological sciences, endoscopy, medical thermography, photography, and microscopy. Some of the technologies used to conduct the aforementioned technique are discussed below.

Medical radiography refers to the use of ionizing electromagnetic radiation such as X-rays to view objects. Medical imaging utilises two forms of radiographic images. Fluoroscopy creates real-time images of internal body structures in a similar fashion to radiography. However, it employs a constant input of low dose X-rays. Projectional radiographs determine the type and extent of a fracture as well as detect the pathological changes in the lungs. Using a radio-opaque contrast medium like barium, X-rays can also be employed to visualise the stomach and intestines' make up.

Magnetic resonance imaging (MRI) instruments, meanwhile, use powerful magnets to polarise and excite hydrogen nuclei in water molecules found in human tissue. This action produces a detectable signal that is spatially encoded to get images of the body. MRI makes use of three distinct types of electromagnetic fields. First is a very strong one on the order of units of tesla. Second, is the static magnetic field to polarise the hydrogen nuclei spatial encoding; and another weak radio-frequency field for the manipulation of the nuclei.