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بسم الله الرحمن الرحيم رب إشرح لى صدرى و يسر لى أمرى وأحلل عقدة من لسانى يفقهوا قولى

بسم الله الرحمن الرحيم رب إشرح لى صدرى و يسر لى أمرى وأحلل عقدة من لسانى يفقهوا قولى. صدق الله العظيم. SPESCIAL X-RAY Equipments. Under supervision of Prof. Dr. Nadher A. Al sherbeny.

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بسم الله الرحمن الرحيم رب إشرح لى صدرى و يسر لى أمرى وأحلل عقدة من لسانى يفقهوا قولى

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  1. بسم الله الرحمن الرحيم رب إشرح لى صدرى و يسر لى أمرى وأحلل عقدة من لسانى يفقهوا قولى صدق الله العظيم

  2. SPESCIAL X-RAY Equipments Under supervision of Prof. Dr. Nadher A. Al sherbeny

  3. *Special X ray equipments are equipments designed for more clear visualization of the radio graphed organs. *It is helping in obtaining more diagnostic information's. *TYPES of Special x ray equipments are : 1- Fluoroscopy 2- Tomography 3- Mammography 4- Stereo radiography 5-Cine fluorography

  4. FLUOROSCOPY

  5. 1- FLOUROSCOPY * In 1896 Thomas Edison invent fluoroscopy . * It enable the examiner to visualizing the radio graphed organ “ life “ visualizing of movements of internal structures & fluids .

  6. * Generally the idea of fluoroscopy is : direct visualization of X ray emerging from the patient. * This visualization occur by many types , according to it fluoroscopy is classified into :

  7. Types of Fluoroscopy :

  8. * 1- Conventional Fluoroscopy : *Image is received on fluoroscopic screen . * Screens are composed of a board of zinc cadmium sulfide * The image formed is a dim image , received in the retina by rods i.e. straining to eye to be detected ( its illumination 0.01 milliLamberts ) N.B. Lamberts & millilamberts : are units for measuring illumination .

  9. *2- Image Intensified Fluoroscopy: * Image is image is intensified by intensifier tube & monitored from it by many ways . * this lead to : - It give more bright image . - Less dose of radiation is used .

  10. Structure & mechanism of Action : * Electric current passing in the tube is less than 5 mA ( While in ordinary apparatuses it is a hundreds of mA ) * This current in every type is :  In Conventional Fluoroscopy = 3 : 5 mA  In Image intensifiedFluoroscopy = 1 : 3 mA

  11. In modern types the examiner can change the brightness of image ( i.e. change in screen contrast  change in KV & mA automatically ) , this called automatic brightness control

  12. * Image Intensification : is the main difference between types of fluoroscopy . # It improve the illumination of image making it at level of cones vision field ( i.e. eye detect this image by cones not rods ) better image . # This is acquired by image intensifier tube .

  13. IMAGE INTENSIFIER TUBE * It is a complex electronic device . * It receive the remnant X ray beam  convert it to light & increase intensity of this light . * STRUCTURE : - 1- Glass envelop : mainly to keep it vacuum & for structural support. 2- Metal shield : surrounding it externally for protection from breakage .

  14. * 3-Input phosphor layer : - receiving the emerging -x ray from the patient & converting it into light photons. -It is a crystals of “zinc cadmium sulfide” - It is the same material used in screens of conventional fluoroscopy .

  15. *4- Photocathode :(Photoemissive surface) -A negative electrode , - Thin , transparent , adherent to input phosphor - Usually composed of Cesium - It is acting by Photoemission phenomenon . Photoemission: is electron emission following light stimulation .

  16. *5- Electrostatic lenses : Focusing electrons emerging from cathode on output phosphor . *6- Anode : Positive electrode , attracting the electrons emerging from cathode & directing it toward output Phosphorus . *7- Output phosphor : Same as input phosphor in structure It is the receiver of the resulted electrons .

  17. How Intensifier tube work? *As intensification of light & increase of illumination level is the main role of this tube , this can occur as following : * X ray exiting from patient pass through glass envelope  input phosphor  visible light photons photoemission of photocathode .

  18. Photoemission  magnified number of electrons  Focused by electrostatic lenses  Attracted by anode  received by output phosphor converting electrons into light but in the form of minified , bright imagewhichmonitored by many ways

  19. An Image of intensifier tube

  20. Illumination of image is increased because , every photon emerged from input phosphor  50 : 75 times on output phosphor . Minification of image also has a big role in increasing brightness . * Brightness gain : is the ability of the image intensifier tube to increase illumination level . * Flux gain : Ratio between number of light photons at output phosphor to those at input phosphor .

  21. Brightness gain = Minification gain X Flux gain * Brightness gain of most tube = 1000 : 5000 * It decrease with tube age & use .

  22. Methods of image monitoring : 1- Mirror optics system 2- Television monitoring system 3- Image orthicon 4- Cine fluorography

  23. 1-Mirror optics system : Magnifying the image formed on output phosphor by a system of optical lenses & mirrors & view it onto a viewing glass . * Disadvantages : 1- Small field , only one person can see image at time . 2- Losing of significant amount of light photons in the optical system.

  24. 2- Television monitoring system : * The intensifier tube is coupled with TV pickup tube * This TV pickup tube is called VIDICON or PLUMBICON . * It convert light from intensifier tube into electric signal , this signals give the image on the TV monitor . * Advantages : 1- Electronic control of contrast & brightness . 2- Image is more bright than mirror optics system . 3- Several observer can see image at same time .

  25. 3-Image orthicon * It is not commonly used . * It is expensive & highly sensitive .

  26. 4- Cine fluorography *MECHANISM: In this type TV pickup tube is replaced by a movie camera . * This camera is taking photos in different speeds ( Framing frequency : 7.5 , 15 ,30 , 60 frame \ sec ) * Cine camera & tube are working together i.e. tube can’t be energized except when camera is working .

  27. *Higher framing frequency  higher radiation dose . * 16 & 35 mm films are used , it played back again for diagnosis . * USE : Mainly in certain angiographic procedures ( esp. cardiac catheterization ) - Low framing frequency ( 7.5 frame/sec) is enough for GIT studies . - Higher frequency is needed for cardiac studies .

  28. * ADVANTAGES : - Higher image quality . - Ability to see the technique life frequently by viewing the movie film . * DISADVANTAGES : - Higher dose of radiation .

  29. FLUOROGRAPHY & SPOT FILM * With fluorography , spot films also could be taken I.e. fluoroscopy  life image & conventional film . * METHOD : * X ray tube is operating in two manners : - Low mA for fluoroscopic imaging (<5mA) - High mA  as used in conventional X ray apparatuses , for spot filming .

  30. * KV operating is different according to the imaged part . * Film loaded in a conventional cassette , it positioned in between patient & image intensifier . * When spot filming is needed , a special button for higher mA exposure is used  radio graphing of the film .

  31. * Recently , SPOT FILM CAMERA is developed. * This camera is take one frame / each exposure . * The camera is taking its image from image intensifier tube . *Advantages of spot film camera : - It need less dose of exposure than in spot film . - It doesn’t interrupt fluoroscopic examination.

  32. TOMOGRAPHY

  33. * TOMOGRAPHY : * It is a procedure designed to focusing certain objects lying in plane of interest & blurring other structures . • *Tomography Vs Plain film : Tomography is focusing certain structure , not as plain film which showing all structures in the same clarity & overlapping each others .

  34. * Other names of tomography : - Body section radiography - Laminography - Planigraphy * Types of topographic movements : - Linear - Circular - Elliptical - Hypocycloidal

  35. LINEAR TOMOGRAPHY * It is simplest type of tomography . * Mechanism of Action : - Tube & film are moving . - Both aremoving in circular manner , i.e. in arcs have the same center . - This center ( Fulcrum ) is present in the plane of interest (i.e. plane of structures to be focused ) - Angle of movement is TOMOGRAPHIC ANGLE , which determine thickness of the plane .

  36. A I I

  37. * The more topographic angle  less plane thickness . * The examination take the following steps: 1- Patient in position , tube present at one side & film facing it in the opposite site . 2- Just when both begin to move , exposure begin . 3- Objects present in plane of interest ( focus ) have the same position on the film in each exposures .

  38. 4- Other objects out side this plane  have different places in each exposure  blurred images of them . 5- Thus a high quality focused image is acquired to the focused . While objects out side this plane are blurred by MOTION UNSHARPNESS

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