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RAD 254 Digital Imaging Basic Elements of Digital Imaging CR/DR CD/DR • • • • • Image data CAPTURE Image data PROCESSING Image DISPLAY Image data ARCHIVING Image data DISTRIBUTION & TRANSMISSION Electronic Imaging • Produce image – Digitize (A-D Converter) • Process Data – Output or D-A Conversion then Analog Display » Network » Archive Image Image Acquisition & Detection • Image detector types: – COMPUTED RADIOGRAPHY (CR) • Photostimulable Phosphor (PSP) – DIRECT RADIOGRAPHY (DDR, “DR”) • Solid State X-ray Detector (SSXD) CR/DR Differences (steps) • COMPUTED RADIOGRAPHY(CR) – X-ray – PSP – A-D Conversion – Data • DIRECT RADIOGRAPHY (DDR, “DR”) – X-ray – SSXD - Data Image Data Processing • The selection of processing algorithms, and anatomic regions and radiographic projections controls how the acquired (latent) image is presented for display Image Display • In both CR and DR, a separate device MUST be used to display (as well as view) the digitized image (video monitor) – High resolution (1.5-2.5k matrix) – Diagnostic – Clinical Review – Web based Image Data Archiving • Storage and retrieval • RAID – Storage – Terabyte (Tb) capacity • Digital Linear Tape (DLT) • Application Software Provider (ASP) Image Data Distribution/Transmission • One of the greatest strengths of a digital imaging system is the ability to share images simultaneously with multiple sites, sometimes over great distances (Iraq) – PACS – Teleradiology Myth • “DR” will turn a bad tech into a good tech! • TRUTH – Digital radiography makes people “stupid” = give them an “auto pilot” mentality Myth • “Positioning and collimation don’t matter” • Truth: Positioning and collimation are MORE critical with digital imaging systems Myth • “X-ray techniques don’t matter – you can use whatever you want.” • Truth: Images almost always look better at higher exposures – very possible to over-expose the patient! Caveat: • Typically use HIGHER kVp – Get the photons to the image receptor – Algorithm to determine image quality • STILL GREAT POTENTIAL TO OVER IRRADIATE THE PATIENT Myth • “DR only operates as a 200 speed system.” • TRUTH: Can operate at whatever speed system you desire… but remember – NOISE vs. X-RAY DOSE Myth • “You can’t use grids with a CR system.” • TRUTH: Grid use is still an important part of obtaining good image quality and controlling scatter Computer Technophobia Nagy, P • “A Symantic study found that 70% of users experienced difficulties with computers. Symptoms included swearing at computers, loss of productivity, and emotional distress. 21% of users suffer from ‘PC RAGE,’ sometimes involving physical assault on and damage of a computer.” Skill sets NOT to forget: • Basic Radiography 101 – Proper patient positioning – Proper beam restriction – Proper exposure factors – Correct patient ID – Correct R and L marker use Skill sets NOT to forget: • Basic x-ray physics – How a radiographic image is made – GOOD image quality elements – Effects of incorrect x-ray exposure selection and image quality New Skill Set Development: • Critical thinking skills • Ability to identify a good image • Knowledge of how to fix a repairable bad image • Understanding the exposure indicator New Terminology • PACS – Picture Archival and Communications Systems • PPACS – Picture and Paper and Communications System New Terminology • Teleradiology • ASP – Application Service Providers • DICOM – Digital Images and COmmunication in Medicine • HL-7 – Health Level - 7 New Terminology • HIS – Hospital Information System • RIS – Radiology Information System • HIS/RIS Broker (make sure they talk to each other) Electronic Medical Record (EMR) • DICOM Standard » Work Stations » HL-7 Standard 21st Century Imaging • • • • • • • All modalities will be in digital format Direct to Digital acquisition (SSXD) On-line access to patient records “Total” patient record (EMR) Software and equipment changes Radiation exposure a MAJOR concern Remote reading stations miles away STOP the BS and just tell me! • In CR – the photostimulable phosphor (just like an intensifying screen) is exposed to x-rays. The PSP cassette is then “scanned” by a laser “reader” to obtain the image (stored images are released as varied shades of “light”) • DR/DD uses a “flat panel detector(s) and a scintillator combined with a photodiode the light produced is “digitized” and translated into “densities” for computer viewing. Thanks to: • Rolando R. Reyes, B.S., R.T.(R) – Senior Project Manager – Eastman Kodak Health Imaging – Rochester, NY