Radiograph

Terminology

The radiography indicates the technique. The radiology is science referring itself to it, as well as the medical Spécialité associated. The latter includes/understands other nonradiographic techniques of Medical imagery like the echography or the Imagerie by magnetic resonance.

Radiology is dealt with by Manipulateur in medical electroradiology for the technical part and ancillary medical gestures, and by a radiologist or radiologist , but also by any Médecin (in particular the urgentists and surgeon S) estimating itself qualified, for the part interpretation and realization of medical gestures.

The radioscopy , shortened sometimes under the term of radioscopy when there is no ambiguity, is a technique of radiography with visualization in real-time on a screen of an image which can be mobile, as within the framework of a Coronarographie, for example.

The radio is a current abbreviation indicating either the end result (the stereotype), or the place where it is made (service of radio).

History

Wilhelm Röntgen (1845-1923) is a German scientist having lived in the Netherlands, appointed professor at the University of Strasbourg in 1872 then with that of Giessen in 1879. During its work, it at the time of working with a cathode tube. It is by occulting it to avoid receiving from it the light which he discovers the existence a fluorescence of a barium platinocyanide screen. It has just discovered a type of radiation ignored hitherto. These rays are stopped neither by paper nor by glass, but are it on the other hand by lead and platinum. Moreover, they impress the photographic plates. Röntgen decides to name this radiation by the letter of the mathematical unknown factor: x-rays. With the end of the year 1895, it carries out the very first radiography of the history, that with the hand of his wife, Berta Röntgen.

It is an almost instantaneous revolution since the first services of medical imagery open with the beginning of the year 1896. Röntgen receives very first the Nobel Prize of physics in 1901. In the interest of medicine, it does not deposit a patent on its discovery.

Thereafter, it is the use of the radiography which involves its own improvement. The power of the tubes to x-rays increases, thus extending the use of this technology of the examination of the ostéo-articular apparatus towards that of the mobile bodies.

It is in years 1970 that x-rays start to be used for Tomodensitométrie (scanner X).

Technique

Radiography, generally, is still carried out on Film, the film being laid out in a protective cassette behind or under the exposed body. Nevertheless, the exclusiveness in radiography on film is generally reserved for the " tables of os" , only dedicated to the examination osseous or arthroscopic. The majority of the systems of medical imagery propose from now on a digitalization of the image carried out by a transformation of x-rays into electrons via a layer of cesium iodide (CsI), that is to say by using an image amplifier (vacuum tube condensing on a secondary screen the electronic image thus made up, this secondary screen being coupled with an optics and a camera); maybe by using a flat panel (diodes ensuring direct conversion readable by electronic circuit), very last thing of the direct medical imagery.

The image is created by the difference in opacity of fabrics to x-rays. the body is composed of fabrics known as " mous" , not very opaque with x-rays (like the skin, grease, the muscles), and of more opaque fabrics (bones, primarily). To obtain a fabric image or bodies not having a specific opacity, one brings in situ a Produit of contrast. It is the case for the imagery of the vessels (carbon dioxide or iodine injection); for the imagery of the digestive system (baryta ingestion or injection, containing barium); for the imagery of the articulations, or arthroscopy (iodine injection); for the imagery of the system of reproduction of the woman, or hysteroscopy (iodine injection).

With the development of the computerization of the hospitals, radiography is allied with data processing to create new systems:

computerized Radiography, or CR: the film is replaced in the cassette by a ERLM, i.e. a screen with phosphorus. The latent image obtained then is activated by a laser scanning and is digitized using a special scanner.
direct numerical Radiography, or DR.: the film is replaced by a sensor connected directly to the computer. See higher " amplifier of luminance" and " sensor plat".

The use of films is reduced in many hospitals, the access to the images on faster, more economic and more ecological screen being.

Standards were established for the information systems of radiology (SIR) and the hospital information systems (SIH). The standard DICOM is a model directed object for the exchange of information of Medical imagery.

The limits of the technique are on two plans. The restored image being a projection in two dimensions, it is necessary to know to interpret the image obtained (except use of rebuilding 3D). In addition, the impact on the organization exists, that it is about the quantity of iodine injected if necessary (limitation function of the renal capacities of elimination of the individual, variable function of the age, the health condition of the patient), or that it is about the exposure to the X-rays in the event of procedure heavy or repeated (possibility of Alopécie or local burn), although medical staffs near the patient are the first concerned with this last risk (exposure whole body, and essentially, repeated).

Numerical radiology allows applications of teleradiology where the doctor who interprets the examination is remote (sometimes even in another country) of the place where this last is carried out. Applications of this technology are effective in certain hospitals of the United States where radiologists, located in India make a first analysis of the stereotypes.

New methods

Radiographie biplane low amount (EOS) uses very low dose of x-rays simultaneously to obtain two images of face and profile of a quality higher than conventional radiography. These images can then be used for the rebuilding 3D of the osseous structures using specialized software.

Famous radiologists

Wilhem Conrad Roentgen, inventor of the first radiographies in 1895. After long work, it gives the first radio operator stereotype of the hand of his wife on December 22nd, 1895.
Godfrey Newbold Hounsfield, inventor in the years 1970 of the first scanner. It received the Nobel Prize of medicine in 1979 for its work.

Scanner

See too

Coronarographie
Angiographie
Cavographie

Notes and reference

Random links:

Dagbladet Information | Roadmender | John Redpath | Manolo Hugué | Jews for Jesus