This document discusses various methods of X-ray examination including direct analogue techniques using radiographic film or fluorescent screens, indirect analogue techniques using image intensifiers, and digital techniques. It also describes the components and functioning of X-ray machines, generation of X-rays, computed tomography which uses thin slices and rotation of the tube and detectors, and the use of contrast media to enhance visualization of organs and tissues.

1. X-Ray methods ofX-Ray methods of
examination.examination.
Bases of X-Ray semioticsBases of X-Ray semiotics
of pathology of differentof pathology of different
organs and systems.organs and systems.

2. 4 modalities (or 4 groups of methods) of modern4 modalities (or 4 groups of methods) of modern
Diagnostic imaging (Radiology):Diagnostic imaging (Radiology):
-- X-ray examinationX-ray examination;;
-- Nuclear medicine imagingNuclear medicine imaging;;
- Di- Diagnosticagnostic ultrasoundultrasound;;
- Magnetic resonance imaging- Magnetic resonance imaging ((MRI)MRI)..
X-ray and radionuclide examinations useX-ray and radionuclide examinations use ionizing radiationionizing radiation
Biological effect isBiological effect is tissue ionization.tissue ionization.

3. X-ray examination methods:X-ray examination methods:
- radiography,- radiography,
- fluoroscopy,- fluoroscopy,
- fluorography,- fluorography,
- tomography,- tomography,
- computed tomography.- computed tomography.
AllAll X-ray examinations are based on the detection ofX-ray examinations are based on the detection of
radiation passed through the patient (transmittedradiation passed through the patient (transmitted
radiation).radiation).

4. Technology of forming of x-ray images
Includes three components:
1 - radiant ( X-ray tube)
2 - object research
3 - perceiving device (detector) on which we get the visual
shadow image of the area that inspects
1
2
3

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6. X-RAY MACHINE
1 - X-ray tube on a stand. 2 - High-voltage transformer, rectifiers
to change the AC current to DC, and a filament supply to control
the temperature of the filament (100-150 Kv applied across the
tube). 3 - Table for patient. 4 - control stand (in other room). 5 -
perceiving device :
- X-ray film.
- Quasi-conductor selenium plates
- Fluorescent screen.
-Electronically-optical
representation amplifier.
- Dosimeter detector.
1
5
3
2, 4
AC- alternate current
DC- direct current

7. X-rays are generated byX-rays are generated by X-ray tubeX-ray tube (( generatorgenerator of radiation).of radiation).

8. X-ray tube has a cathode, which emits electrons intoX-ray tube has a cathode, which emits electrons into
the vacuum and an anode to collect the electrons, thusthe vacuum and an anode to collect the electrons, thus
establishing a flow of electrical current, known as theestablishing a flow of electrical current, known as the
beam, through the tube.beam, through the tube.
A high voltage power source, for example 30 to 150A high voltage power source, for example 30 to 150
kilovolts (kV), is connected across cathode and anodekilovolts (kV), is connected across cathode and anode
to accelerate the electrons.to accelerate the electrons.
The X-ray spectrum depends on the anode materialThe X-ray spectrum depends on the anode material
and the accelerating voltage.and the accelerating voltage.

9. Electrons from the cathode collide with the anodeElectrons from the cathode collide with the anode
material, usually tungsten, molybdenum or copper,material, usually tungsten, molybdenum or copper,
and accelerate other electrons, ions and nuclei withinand accelerate other electrons, ions and nuclei within
the anode material.the anode material.
About 1% of the energy generated is emitted/radiated,About 1% of the energy generated is emitted/radiated,
usually perpendicular to the path of the electronusually perpendicular to the path of the electron
beam, as X-rays. The rest of the energy is released asbeam, as X-rays. The rest of the energy is released as
heat.heat.

10. Over time, tungsten will be deposited from the targetOver time, tungsten will be deposited from the target
onto the interior surface of the tube, including theonto the interior surface of the tube, including the
glass surface.glass surface.
This will slowly darken the tube and was thought toThis will slowly darken the tube and was thought to
degrade the quality of the X-ray beam.degrade the quality of the X-ray beam.
As time goes on, the tube becomes unstable even atAs time goes on, the tube becomes unstable even at
lower voltages, and must be replaced.lower voltages, and must be replaced.

11. research room
( manipulation
room)
Protective
wall
Corridor
Photographic
Laboratory
room of operator
(assistent of doctor)
Doctor’s
room
Typical plan of roentgenologic department

12.  NB!NB! Different tissues provide different degrees ofDifferent tissues provide different degrees of X-X-
ray attenuation.ray attenuation. Attenuation is aAttenuation is a loss of X-ray energyloss of X-ray energy..
Different tissues allow the transmission of differentDifferent tissues allow the transmission of different
amounts of X-ray. X-ray imaging is theamounts of X-ray. X-ray imaging is the imaging ofimaging of
shadows.shadows. X-rays penetrate tissues and are detected onX-rays penetrate tissues and are detected on
the other side of the patient by different detectors.the other side of the patient by different detectors.
Main groups of X-ray techniques:Main groups of X-ray techniques:
 I)I) direct analogue techniques,direct analogue techniques,
 2)2) indirect analogue techniques,indirect analogue techniques,
 3)3) digital techniques.digital techniques.

13. Direct analogue techniques:
The final X-ray image is created directly on detector.
Detector: radiographic film or fluorescent screen.
The radiographic film responds with
blackening, the fluorescent screen
by fluorescence.
Two main direct of analogue techniques:
direct radiography and direct fluoroscopy.

14. DDirect radiography:irect radiography: the X-rays, after having passed through thethe X-rays, after having passed through the
patient, create an image directly on a radiographicpatient, create an image directly on a radiographic filmfilm. A 3-. A 3-
dimensional object is projected into a 2-dimensional image.dimensional object is projected into a 2-dimensional image.
ShadowsShadows of different organs areof different organs are summatedsummated on film. The imageson film. The images
only become visible after treatment with a developer. The image isonly become visible after treatment with a developer. The image is
negativenegative: the shadows of heart and bones are visualized as white or: the shadows of heart and bones are visualized as white or
light (so-calledlight (so-called opacityopacity), because they efficiently stops), because they efficiently stops
X-rays. Soft tissues are seen in grey tones andX-rays. Soft tissues are seen in grey tones and
gas is seen as black (so-calledgas is seen as black (so-called lucencylucency).).

15. DDirect fluoroscopyirect fluoroscopy (screening): the transmitted X-ray beam fall on(screening): the transmitted X-ray beam fall on
a fluorescent screena fluorescent screen, resulting in a, resulting in a dynamicdynamic projection light image.projection light image.
The image isThe image is positivepositive. The shadows of bones and heart are black. The shadows of bones and heart are black
((real opacityreal opacity), and gas is seen as white or light (), and gas is seen as white or light (real lucencyreal lucency).).
NB!NB! The image can be observed directly by the radiologist onThe image can be observed directly by the radiologist on
screen!screen!
Indirect fluoroscopyIndirect fluoroscopy employs X-ray image intensifier and TV-employs X-ray image intensifier and TV-
technique. Primary projection image is created on a fluorescenttechnique. Primary projection image is created on a fluorescent
screen, but screen image is not observed directly. The screen isscreen, but screen image is not observed directly. The screen is
part of anpart of an X-ray image intensifierX-ray image intensifier that enhances the brightness ofthat enhances the brightness of
the primary image. The intensified image may be recorded viathe primary image. The intensified image may be recorded via
lenses by a TV camera and shown on a monitor. The image islenses by a TV camera and shown on a monitor. The image is
positivepositive..

16. The image on fluorescent screen may also be reflected byThe image on fluorescent screen may also be reflected by
a mirror to a small-film still camera. Filming with this cameraa mirror to a small-film still camera. Filming with this camera
isis fluorographyfluorography (spot filming).(spot filming).
NB!NB! Sizes of fluorograms areSizes of fluorograms are
7x7 or 10x10 sm.7x7 or 10x10 sm.

17. TomographyTomography (conventional tomography):(conventional tomography):
- provides "- provides "sectionalsectional" images;" images;
- is based on- is based on movementmovement of X-ray tube andof X-ray tube and
film in such a way thatfilm in such a way that only a thin planeonly a thin plane throughthrough
the patient, parallel to the film, isthe patient, parallel to the film, is imaged sharplyimaged sharply..
Structures located in other planes (closer or more distant toStructures located in other planes (closer or more distant to
the film) are blurred due to dynamic unsharpness.the film) are blurred due to dynamic unsharpness.

18. Digital X-Ray techniques:Digital X-Ray techniques:
1.1. Digital radiography:Digital radiography:
exposure to X-rays special imaging plates retain a latentexposure to X-rays special imaging plates retain a latent
image of stored energy scanning the imaging plate with aimage of stored energy scanning the imaging plate with a
laser beam releasing energy as light or luminescencelaser beam releasing energy as light or luminescence
(the light intensity is proportional to the absorbed dose of X-(the light intensity is proportional to the absorbed dose of X-
ray photons) recording the emitted light by a photoray photons) recording the emitted light by a photo
detector as analogue signals digitizing the signalsdetector as analogue signals digitizing the signals
image in a grey scale format on a monitor (may beimage in a grey scale format on a monitor (may be
hardcopied by a laser printer).hardcopied by a laser printer).
2.2. Digital fluoroscopy/ digital fluorographyDigital fluoroscopy/ digital fluorography ::
digitizing the analogue video signal from the TV camera indigitizing the analogue video signal from the TV camera in
an X-ray image-intensifier-television system image onan X-ray image-intensifier-television system image on
TV monitor (TV monitor (digital fluoroscopy)digital fluoroscopy) image photographedimage photographed
by a small-film camera (by a small-film camera (digital fluorographydigital fluorography).).
The primary image at digital techniques isThe primary image at digital techniques is positive!positive!

19. Computed Tomography:Computed Tomography:
onlyonly thin tissue slicesthin tissue slices are exposed to X-rays!are exposed to X-rays!
The tube and detectorsThe tube and detectors rotate togetherrotate together around thearound the
patient.patient.
Thin beam of X-rays, perpendicular to the long axis ofThin beam of X-rays, perpendicular to the long axis of
the body, emitted from the tube transmitted thethe body, emitted from the tube transmitted the
beam of X-rays through the patient detection bybeam of X-rays through the patient detection by
scintillationscintillation oror ionization detectorsionization detectors..
CT detectors are at least 100 timesCT detectors are at least 100 times more sensitivemore sensitive thanthan
radiographic film!radiographic film!

20. Computed Tomography:Computed Tomography:
Advantages of CT:Advantages of CT:
- good contrast resolution;- good contrast resolution;
- sectional images of any part of the body;- sectional images of any part of the body;

21. Computed Tomography:Computed Tomography:
Advantages of CT:Advantages of CT:
-- measurementmeasurement of tissue attenuation:of tissue attenuation:
linear scale ranges from -1,000 to 3,000 of Hounsfield unit (HU).linear scale ranges from -1,000 to 3,000 of Hounsfield unit (HU).

22. Computed Tomography:Computed Tomography:
Advantages of CT:Advantages of CT:
NB!NB! A recently introduced spiral and multislice CT haveA recently introduced spiral and multislice CT have
increased the efficiency of CT scanningincreased the efficiency of CT scanning
very high quality three-dimensional reconstructions.very high quality three-dimensional reconstructions.

23. CContrast mediaontrast media for X-Ray examinationfor X-Ray examination
Purpose:Purpose: visualization of empty and somevisualization of empty and some
parenchymal organs in conventional radiologyparenchymal organs in conventional radiology
and CT.and CT.
Negative contrast mediaNegative contrast media (air and other gases):(air and other gases):
attenuate X-rays less than the soft tissuesattenuate X-rays less than the soft tissues
and are seen asand are seen as lucencylucency..
Positive contrast media:Positive contrast media:
attenuate X-rays more than the soft tissuesattenuate X-rays more than the soft tissues
and are seen asand are seen as opacityopacity..
Positive contrast media:Positive contrast media:
-- water solublewater soluble (water solutions of organic(water solutions of organic
compounds with iodine),compounds with iodine),
-- water insolublewater insoluble (barium sulphate).(barium sulphate).

24. Water soluble contrast mediaWater soluble contrast media are used for:are used for:
- urography,urography,
- cholangiography,cholangiography,
- angiography and angiocardiography;angiography and angiocardiography;
- bronchography;bronchography;
- hysterosalpingography;hysterosalpingography;
- enhancing attenuation differences at CT.enhancing attenuation differences at CT.

25. Water insoluble contrast mediaWater insoluble contrast media are used for :are used for :
- conventional X-ray examination ofconventional X-ray examination of esophagus,esophagus,
stomach and duodenumstomach and duodenum (performed with single-(performed with single-
or double-contrast barium meal; for the double-or double-contrast barium meal; for the double-
contrast study combination barium-gas is used);contrast study combination barium-gas is used);
- conventional X-ray examination ofconventional X-ray examination of large bowellarge bowel
(performed with the single- or double-contrast(performed with the single- or double-contrast
barium enema –barium enema – irrigographyirrigography).).
NB!NB! As a rule, so-called barium studiesAs a rule, so-called barium studies
are fluoroscopy, during it radiographyare fluoroscopy, during it radiography
usually is performed.usually is performed.