Fluoroscopy (synonym transillumination) is one of the main methods of radiological research, which consists in receiving transmission (fluorescense) the screen plane positive image of the object. Under fluoroscopy is investigated between translucent screen and the x-ray tube. Modern x-ray translucent screens, the image appears at the moment of inclusion of x-ray tube and disappears immediately after the power is turned off. X-rays usually made well in a darkened room of the x-ray Cabinet (see) or, in rare cases, at the patient's bed in the bright room with CryptoAPI (see). Tripods modern x-ray machines allow to inspect both in horizontal and vertical direction rays and vertical (Fig. 1) or horizontal (Fig. 2) position the analyzed. An x in a horizontal position investigated and horizontal rays is called literackiej. An x in a horizontal position investigated and vertical rays is called trojskaya(see). Because of the small image brightness x-ray requires preliminary adaptation eyes to the darkness. To avoid loss of adaptation should not be in between prosvechivaniya to include in the office bright lighting.
Fig. 1. Fluoroscopy in vertical position investigated.
Fig. 2. Fluoroscopy in a horizontal position investigated.
X-rays are produced mainly in the diagnostics of diseases of internal organs located in the abdominal and chest cavities, according to the plan, which is a radiologist is before fluoroscopy. Sometimes the so-called review x-rays used in the recognition of traumatic injuries of the bones to clarify choreograph radiography. Transillumination can produce a doctor. Roentgenologist is obliged to monitor the observance of technical conditions of x-ray and to be prepared at the request of the doctor to switch between the mode of scanning mode images.
X-rays usually done with an electric current through the x-ray tube is within 2 to 5 mA and voltage on the tube from 45 to 85 sq In order antiradiation protection , observe the following conditions: to fluoroscopy necessarily with a filter made of aluminium with a minimum thickness of 1 mm; apply skin-focal length (distance from the tube focus to the patient's skin) not less than 35 cm; full use of available means antiradiation protection (leaded glass on the screen, protective covers, aprons, gloves); take into account the time of scanning and report the results to the doctor through every 2 minutes; when writing patients with an x to find out from them before fluoroscopy prescription terms of the previous prosvechivanie and images to account for a total dose of radiation in order not to exceed the maximum permissible dose (see). In order to preserve the fluorescent properties of the screen, you must protect it opaque curtain (the best of black material) from the action of visible light, and exposure to moisture and heat. At decrease of fluorescent properties screen, you should replace it with a new one.
Cm. also x-Ray, x-ray Screens.
Fluoroscopy (synonym transillumination) is one of the main methods of radiological research, which fluorescense the screen during the power-on x-ray tube occurs plane positive image of the object. Fluoroscopy is carried out in the x-ray Cabinet (see) or another darkened room, much less often - in a light room with CryptoAPI or electronic-optical amplifier (see). Studied fits between handset and translucent x-ray screen (Fig. 1). The scanning is performed when the voltage on the tube 45-85 kV and current 2-5 mA depending on the density of the object and the examined organ.
The intensity of the shadow of a particular organ, tissue, abnormal formation under fluoroscopy depends on the extent of absorption of x-ray radiation. The higher the share of the fabric, the more expressed its ability to absorb x-rays and the more intense the shade it provides on the screen. Shadow intensity depends also on the volume of the object. Two objects with the same specific gravity greater volume gives a more intense shade.
On the basis of a positive image of the investigated object, obtained on fluorescense screen, less intense shade compared to the more dense referred to as enlightenment. Such enlightenment can be a result of both changes in the structure of the object, and projection mapping on the examined organ or tissue substrates, to a lesser extent delaying x-ray.
In contrast to the chest, representing favourable object for x-ray, abdominal cavity with its contents and retroperitoneum because of topographic anatomy and rentgenometricheskikh features are not differentiated in normal x-ray.
If shadow hearts is well seen on the background of clear lung fields, and elements of a skeleton is clearly stand out on the background of soft tissues, to identify the liver, biliary tract, spleen, gastrointestinal tract, urinary tract on the background of the surrounding soft tissues and organs usually resort to the contrasting methods of research. Artificial contrasting extremely extends the use of x-rays in the diagnosis of diseases of various organs and systems. Spatial representation, based on the study of Scialoia, rentgenoterapii, along with x-ray and clinical semiotics and mastering the methods and techniques of x-rays help in the interpretation of the received x-ray images. Direct image of the investigated object through the use of divergent beam on the screen is always increased.
Projection increase can be significantly reduced by teleroentgenography, i.e., with increasing distance object - tube.
Fluoroscopy is a constituent element of the numerous special methods of x-ray studies. However, in some cases, the data of x-ray sufficient for the diagnosis of disease. Along with the main advantage of fluoroscopy - simplicity and possibility to study the functional state of the examined organs - it is not without some drawbacks. Because of physiological peculiarities of our sight low brightness of the image on translucent screen, even with a good adaptation of view (for 20 minutes) does not allow to consider it fine detail, determined with x-ray (see).
In addition, when x-ray radiation dose of the investigational significantly higher than in radiography. To reduce the dose of ionizing radiation received by patients and staff, should seek to limit the duration of x-raying.
Fluoroscopy and radiography not compete with each other, but complement each other. An important additional data can be obtained with prepositional R., which applies not only rotoscope, waterscape (Fig. 2), tracheascopy (Fig. 3), but is the rotation of the patient around three main axes. R. allows you to easily differentiate calcification in the extension of the mucous bag shoulder joint with compact island spongy bone tissue in the head of the humerus (Fig. 4), etc., currently a number of special methods for x-ray examinations under the supervision of R. (sounding of the heart and major vessels, bronhografiya, swelling of hollow organs gas and so on). Significantly improve the results fistulografii, electroencephalography, pneumomediastinum, holegrafii, etc. if they are advantages and merits R.
Essential help in the diagnosis of a number of organs and systems is the so-called x-ray palpation, i.e. palpation of the investigated organ during fluoroscopy. Skillful palpation allows you to explore the subtle details of the structure of the mucous membrane of the stomach (Fig. 5)to identify the source of pain sensitivity, and establish relations palpable tumors to adjacent tissues and organs. "X-ray palpation helps to specify the localization of metallic foreign bodies and smexiest normal and pathological formations.
X-ray proved to be very effective not only in x-rays (see) when establishing topography, anatomic-morphological features of the pathological process, the identification of functional-dynamic shifts, but in radiotherapy (see), in which R. helps to precisely direct the Central beam on deeply located tumor. R. contributes to fixing aligned images of several significant items in the optimal provisions of the patient at the most critical moments of the study. But especially effective R. in the study of respiratory excursions aperture results in the Valsalva index and Muller, when monitoring heart rate and pulsation of vessels, peristaltic contractions of the walls of the esophagus and gastrointestinal tract, etc., Fluoroscopy, are also used to detect the horizontal level of the liquid and gas in the organs of chest and abdominal cavity, sinuses, radiography in atypical projections, especially when performing tangential pictures.
In order to reduce radiation exposure to the patient and staff R. must be conducted according to a plan, methodologically consistent, rational irised that reducing secondary radiation, improves the visibility of the image, reduces radiation exposure. The decrease of the latter is achieved as well as the distance of the focus-tube - object, the application of aluminum filters thickness of 3-4 mm, at the x-raying tougher rays and small amperage (1-3 mA). Means of individual protection of personnel are protective aprons, screens, gloves, lead-impregnated glass on the translucent screen, and other
Currently, in connection with the use of electron-optical Converter and x-ray television role fluoroscopy increases.
The use of modern achievements of electronics in radiology allows to increase the brightness of the image, significantly reduce radiation exposure and to make the study of light or malosemeynom room, so there is no need to adapt to the darkness.
Under normal conditions, the transmission is significantly reduced visual acuity, distinguishing the eye's sensitivity to the contrast, quickness of perception.
The use of electron-optical Converter and x-ray television creates the conditions under which a person's eyes when scanning a Discerner of the same amount of detail, what he sees in the picture, but with the introduction of rentgenonegativee there were conditions created for the most complete documentation fluoroscopic images. Cm. also x-Ray examination.
Fig. 1. Fluoroscopy in a vertical position investigated.
Fig. 2. Fluoroscopy in a horizontal position studied (using luteriska).
Fig. 3. Fluoroscopy in a horizontal position studied (using trachoma).
Fig. 4. Differential diagnosis between compact island (1) and lime bursitis (2).
Fig. 5. X-rays of the stomach, obtained by x-ray palpation".