mobile image intensifier units.ppt
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The document discusses mobile image intensifier units, detailing their components, functionality, and technical capabilities. It explains the role of the C-arm in fluoroscopy, the types of imaging and cameras used, and radiation protection measures. Future developments suggest a shift towards flat panel detectors, which promise improved image quality and reduced patient radiation exposure.
mobile image intensifier units.ppt
- 1. MOBILE IMAGE INTENSIFIER UNITS Mr.SAMEERAHMADGANIAE ASSISTANTPROFESSORCOPMSADESHUNIVERSITY, BATHINDAPUNAJB
- 2. TOPICS FOR DISCUSSION • INTRODUCTION • COMPONENTS OF AN IMAGE INTENSIFIER • MOBILE IMAGE INTENSIFIER UNITS X- RAY TUBE MOVEMENTS CONTROL CONSOLE TECHNICAL & ELECTRONIC CAPABILITIES TYPE OF TV CAMERA GENERATOR & RANGE OF EXPOSURES RISKS & REMEDIES FUTURE DEVELOPMENTS.
- 3. INTRODUCTION FLUOROSCOPY • IMAGE INTENSIFIERS • IMAGE INTENSIFICATION • USES OF IMAGE INTENSIFIERS • PRINCIPLE OF IMAGE INTENSIFIERS.
- 4. COMPONENTS OF AN IMAGE INTENSIFIER An input screen- (input phosphor): Na activated CsI. 12.5-35cm diameter Photocathode- antimony, potassium Output phosphor : Silver activated Zinc-Cadmium Sulphite, 1.3cm diameter Introduced by Philips in 1955.
- 5. MOBILE IMAGE INTENSIFIER UNIT - THE C-ARM Produces a “live “ image which can be displayed on a TV Screen. • Two monitors are used which is possible to compare an image from the memory circuit with the another one in real time. • TV monitors are separate from the c-arm • Wheel base is made up of special conducting rubber. This prevents the built up of static electric charge.
- 6. THE C-ARM
- 7. • Micro focus x-ray tube (0.02- 0.10mA) • Tube potential (40-75 kV & uses a narrow field 10-15cm in diameter), • Less ionization radiation than the usual instruments.
- 8. X-RAY TUBE • FIXED ANODE Anode heat capacity- 30,000- 50,000 HU • Single/ dual focused anode: • (0.6mm x 0.6mm – fluoroscopic applications • 1.8 x1.8mm- radiographic applications). • ROTATING ANODE Anode heat capacity: 30 lacs HU Focal spot : 0.3mm (better image)
- 9. MOVEMENTS Helps rapid and easy positioning of the X-ray tube & the intensifier tube. Horizontal travel : about 200mm Orbital travel : about 115o Motorized vertical travel :460mm Wig-Wag about +/-12cm
- 10. CONTROL CONSOLE a) Various handles for movement and positioning b) power switch and exposure switch. c) cable hanger d) Brake pedal e) controls for radiographic and fluoroscopic settings. f) Hard disc and optical disc writer. g) Ability to save and swap images between monitors. h) Advanced image quality enhancement software such as noise reduction, zoom control I ) Contrast and brightness controls.
- 11. ELECTRONIC CAPABILITIES The images can be manipulated in many ways on the computer screen. a) Cine loop replay- allows review of a dynamic scene without extra dose. b) Cine loop editing- shorter loops can be made over review of a dynamic scene. c) Zoom –fast magnification d) Relative stenosis measurement - Can measure the distance of vessels for vascular procedures. e) Test annotation- To label all images.
- 12. TECHNICAL CAPABLITIES 1) Plain fluoroscopy or 2) DSA (Digital subtraction angiography) (fluoroscopic technique to clearly visualize blood vessels in the bony/ dense environment. Pre contrast image - Post contrast image). • All image intensifiers are set up with the s/w capable of adjusting settings to suit different user requirements, depending on the procedure and body area being imaged.
- 13. TYPE OF TV CAMERA Older machines= Vidicon type pick up tube with direct fiber- optic coupling to the image intensifier. Modern machines= CCD cameras operates at lower voltages than vidicon more durable than vidicon tubes. emits electrons in proportion to light striking photo cathode. fast discharge eliminates lag.
- 14. GENERATOR & RANGE OF EXPOSURES X-ray tube & high frequency generator placed in the tube head as a tank construction. multi cord low tension cable connects the generator to the controls. • KVp settings = 40 KV-110KV • Tube current= 0.1mA – 6mA(fluroscopic ) = 20mA- 60mA (radiographic) • Electronic Timer= 0.1 sec to 3.0 sec
- 16. RADIATION PROTECTION • Minimum source to skin distance = 12” • distance from tube and patient • ↓ distance from intensifier tube to the patient • 5 min Audible Alarm • At least .25mm lead apron to be worn • Never place your hand or other body part in primary beam • Provide gonadal protection for the patient if possible Achieve maximum distance from the patient and tube (stand 90° from the patient- SEE Merrills – pg 212) • Minimum of 6 feet exposure cord for radiography
- 17. RISKS & REMEDIES RISKS • RADIATION Increased radiation dose & radiation to every one in the theatre INFECTION taking infection into the theatre. EXPLOSION : equipment may produce spark & produce explosion , because of the anesthetic gas. REMEDIES • Use cone / internal diaphragms, wear aprons. • use shielding covers, should not use in other wards. • Wheels made of special conducting rubber avoid spark.
- 18. FUTURE DEVELOPMENTS • FLAT PANEL DETECTORS-(Image Intensifier Replacement). ADVANTAGES • offers increased sensitivity to X-rays hence low patient dose. • Increase image quality. Flat panel detectors are currently offered by Philips Healthcare under the product name Veradius.
- 19. THANK YOU