Introduction
Radiology is a branch of medicine that uses electromagnetic and mechanical radiation for scientific purposes or in everyday clinical practice for diagnostic and therapeutic purposes. Radiology is a rapidly developing and growing field that began with Wilhelm Conrad Röntgen in 1895 in Würzburg. Initially, only X-rays were used.
In the course of time, other so-called “ionizing rays” were also used. Magnetic resonance imaging is another aspect of radiology. It does not use ionizing radiation, but electromagnetic fields.
Radiotherapy in therapeutic medicine is also a sub-area of radiology. It is used, for example, in cancer treatment. Diagnostic radiology takes up the largest share of radiology in everyday clinical practice.
Ultrasound is also a sub-area of radiology and is the most frequently used radiological imaging procedure. The simplest imaging with ionizing radiation is conventional radiography. An X-ray beam is generated by means of two electrodes.
A filament, the “cathode”, releases small electrons and accelerates them strongly. The electrons hit the opposite second electrode, the “anode”, and collide with it so strongly that a so-called “braking radiation” is produced. The braking radiation is the X-ray beam, which is now directed at the patient.
The rays pass through the patient and are captured and recorded on the other side. In the past, this happened on X-ray film; today there are digital detectors for recording. With the help of the radiation, one makes use of the fact that structures in the body have different densities and are made of different materials.
When rays hit them, they absorb parts of the radiation. Depending on which areas of the body the rays pass through, the stronger or weaker they are perceived and recorded on the other side of the body. These shadows then overlap to form a two-dimensional image and you get a snapshot of the inside of the body.
A computed tomography (CT) works according to a very similar mechanism. However, it provides more images from different planes and thus more information about the inside of the body. Magnetic resonance imaging (MRT) is also frequently used in the clinic.
MRI works with a different, healthier mechanism and provides detailed information about the human soft tissue. Ultrasound, X-rays, CT and MRI have become indispensable as imaging diagnostic procedures in modern medicine. In some cases, they can be supplemented by contrast agents to enable more contrasted examination of organ areas and structures.
