1 / 112

Computed Radiography and Digital Radiography

Computed Radiography and Digital Radiography. filmless’ radiology departments. Diagnostic radiographers have traded their ______ and _________ for a __________ and __________ advance for Rad Sci Prof, 8/9/99. Digital imaging is the acquisition of images to a computer rather than

nhampton
Download Presentation

Computed Radiography and Digital Radiography

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Computed Radiography and Digital Radiography

  2. filmless’ radiology departments Diagnostic radiographers have traded their ______ and _________ for a __________ and __________ advance for Rad Sci Prof, 8/9/99

  3. Digital imaging is the acquisition of images to a computer rather than directly to film. What Is Digital Imaging?

  4. New Technology • Has impacted everyone: • Practicing radiologic technologist • Educators • Administrators • Students in the radiologic sciences.

  5. Computed Radiography Fundamentals of Computerized Radiography

  6. Radiology 1895Radiology 2001

  7. CR SYSTEM COMPONENTS • CASSETTES (phosphor plates) • ID STATION • IMAGE PREVIEW (QC) STATION • DIGITIZER • VIEWING STATION

  8. History of CR INDUSTRY • Theory of “filmless radiography” first introduced in 1970 • 1981 Fugi introduced special cassettes with PSP plates (replaces film) • Technology could not support system • First clinical use in Japan - 1983

  9. Predictions • 1980 – Bell Labs believed that Unix would be the worlds dominant operating system • 1982 – Bill Gates thought 640K of main memory would suffice for workplace operating systems ( This presentation is 80,000 kb) • 1984 – IBM predicted that personal computers would not amount to anything

  10. History of CR • By 1998 – over 5,000 CR systems in use nationwide • 1998 – Local area hospitals begin to incorporate CR systems in their departments • (Riverside Co. Hosp builds new hospital in Moreno Valley) – completely CR system – 1st generation equipment

  11. TERMINOLOGY • F/S - ______________________ • CR - _____________________ • DR - _____________________ • DDR - _____________________

  12. IMAGE CREATION • SAME RADIOGRAPHY EQUIPMENT USED • THE DIFFERENCE IS HOW IT IS • ___________ • ___________ • ___________ • ___________

  13. Conventional vs. Digital Imaging • Conventional X-ray imaging systems • Produce an analog image (radiographs, & fluoroscopy). • Using x-ray tube with films & cassettes

  14. Conventional vs. Digital Imaging • Digital radiography systems require that the electronic signal be converted to a digital signal – • Using x-ray tube – • CR cassettes with phosphor plate (PSP) • DR systems with transistors (TFT)

  15. COMPUTED RADIOGRAPHY & DIRECT RADIOGRAPHY& FILM SCREENIMAGE CAPTURE FS - Film inside of cassette CR – Photostimuable Phosphor Plate (PSP) DR(DDR) - Thin Film Transitor (TFT)

  16. Cassette with film CR with PSP

  17. Directed Digital Radiography(DDR) Directed digital radiography, a term used to describe total electronic imaging capturing. Eliminates the need for an image plate altogether.

  18. Amorphous Selenium detector technology for DR Direct Radiography

  19. IMAGE CAPTURE • _____________ • PSP – photostimulable phosphor plate • Replaces film in the cassette • _____________ – No cassette- • Photons captured directly onto TFT • Sent directly to a monitor

  20. CR PSP in cassette Digital image Scanned & read- CR reader COMPUTER Image stored on computer Viewed on a Monitor Hard copy (film) can be made with laser printer FILM Film in cassette loaded in a darkroom Processed in a processor FILM Hard copy image – stores the image Viewboxes – view the images CR vs. FS

  21. CR BASICS • Eliminates the need for film as a recording, storage & viewing medium. • PSP Plate – receiver • Archive Manager – storage • Monitor - Viewing

  22. General Overview CR • PSP cassette exposed by conventional X-ray equipment. • Latent image generated as a matrix of trapped electrons in the plate.

  23. CR – PSP plate • Photostimulable phosphor (PSP) plate • Captures photons • Stored in traps on plate (latent image) • PLATE scanned in CR READER

  24. CR Phosphor Plates ABSORPTION EMISSION LASER STIMULATION ELECTRON TRAP ELECTRON TRAP X-RAY LIGHT

  25. CR – PSP plate • Stimulated by a ________________ LIGHT • Energy is ________ in a form of _____ light • LIGHT captured by photomultiplier tube (PMT) • Changed to a __________________ signal

  26. How CR works • Blue released light is captured by a PMT (photo multiplier tube) • This light is sent as a digital signal to the computer • The intensity _________ of the light – correlates to the ______ on the image

  27. CR “PROCESSORS”

  28. Densities of the IMAGE • The light is proportional to amount of light received • Digital values are then equivalent (not exactly the same) to a value of optical density (OD) from a film, at that location of the image

  29. ERASING PLATE • After image is recorded • Plate is erased with high intensity _______________________ light • Cassettes are reused

  30. CR VS. DR • CR -______________ where the image is first captured on plate and stored = then converted to digital signal • DDR -____________ where the image is acquired immediately as a matrix of pixels – sent to a monitor

  31. Digital Radiography Direct Capture Indirect Capture Computed Radiography (CR) Direct-to-Digital Radiography (DDR)

  32. DIRECT RADIOGRAPHY • Uses a transistor receiver (like bucky) • Captures and converts x-ray energy directly into digital signal • Images seen immediately on monitor • Sent to PACS/ printer/ other workstations FOR VIEWING

  33. CR Imaging plate Processed in a Digital Reader Signal sent to computer Viewed on a monitor DR Transistor receiver (like bucky) Directly into digital signal Seen immediately on monitor CR vs DR

  34. CR 4000 x 4000 Image only as good a monitor* 525 vs 1000 line More pixels = more memory needed to store CR 2 -5 lp/mm RAD 3-6 lp/mm DR ? IMAGE APPEARS SHARPER BECAUSE CONTRAST CAN BE ADJUSTED BY THE COMPUTER – (DIFFERENCES IN DENSITY) Image Resolution –(how sharply is the image seen)

  35. ADVANTAGE OF CR/DR • Can optimize image quality • Can manipulate digital data • Improves visualization of anatomy and pathology • AFTER EXPOSURE TO PATIENT

  36. ADVANTAGE OF CR/DR • Changes made to image after the exposure • Can eliminate the need to repeat the exposure

  37. ADVANTAGE OF CR/DR vs FS • Rapid storage • Retrieval of images NO LOST FILMS! • PAC (storage management) • Teleradiology - long distance transmission of image information • Economic advantage - at least in the long run?

  38. CR/DR VS FILM/SCREEN • FILM these can not be modified once processed • If copied – lose quality • DR/CR – print from file – no loss of quality

More Related