Prin Radiographic Imaging I
Prin Radiographic Imaging I RADS 1312
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This 17 page Class Notes was uploaded by Henri Cartwright on Thursday October 15, 2015. The Class Notes belongs to RADS 1312 at Midwestern State University taught by Staff in Fall. Since its upload, it has received 37 views. For similar materials see /class/223506/rads-1312-midwestern-state-university in Radiologic at Midwestern State University.
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Date Created: 10/15/15
Slide 1 Slide 2 Slide 3 39 My 39 if mililh RAD S 13 12 Principles of Radio graphic Imaging I Increased Attenuation Additive Conditions Requires an increase in kVp AEC systems 4 Example conditions Slide 4 v S Abscess Edema Tumors Slide 5 Atelectasis Pneumoconioses Bronchiectasis Pneumonia Cardiomegaly Pneumonitis Congestive Heart 39 Pneumonecmmy Failure 0 Pulmonary Edema Empyema Tuberculosis Pleural Effusions Hemotho raX HydrothoraX W W4 is Slide 6 Aortic Aneurysm Acites Cirrhosis Calci ed stones Slide 7 Slide 8 Slide 9 quot p w EA tremi Osteo chondroma Acromegaly Hydrocephalus osteitis deformans Osteoblastic 39 SClerOSiS Metastases Osteopetrosis Chronic Osteomyelitis Paget s disease Technical factors 0 Destruction of tissue andor bone Multiple Sites 7 Anorexia 7 Atrophy 7 Emaciation Slide 10 Slide 11 Slide 12 Emphysema Pneumothroax Aerophagia Bowel obstruction 394 J44 Wm M1 3 i in quot Ext mities cm 5th Active osteomyelitis Hyperparathyroidism Aseptic necrosis Multiple myeloma Carcinoma Osteolytic metastases Degenerative Arthritis Osteomalacia Fibrosarcoma Osteoporosis Gout Slide 1 Intensifying Screens RADS 1312 Fri c39 les of Radiographic lmagmg Slide 2 Objectives Upon completiov I Explain the purpose of radiographic intensifiying screens Describe the function ofeach layerof an intensifying screen I Evaluate the desirability of phosphor aterials according to atomic numbe conversion efficiency spectral emiss 391 ion and fluorescence Shde 3 Objectives I Describe luminescence Describe how to i Analyzethe effect of 393ng qquot quot quot39quot phosphor crystalsixeV 39 la enhickness I classify intensifying mmquot on screens according to quot ef39 lntensl catlonfactor 39menSIfV quot9 fee descrip i e rati n resolution reh v ed I Explain the effect of Desc I the eff of K lmlscreen contact on shell absorption edges resolution on intensifying screens Slide 4 Slide 5 Slide 6 Objectives I Describe the components of a radiographic cassette I Describe the propercleaning and care of radiographic cassettes and screens I Evaluate filmscreen combinations for specific clinical uses Construction l Radiolucent plastic coated with phosphors I Phosphors emit light when radiated I Mounted in pair inside the top and bottom ofa radiographic cassette I Cassette must be lightproof Components I Base 1 Made of polyester plastic1 mm thick i Must be flexible but tough chernicaiiy inert and unifor n rigid mly radioiuce t Slide 9 Slide 7 Components I Re ective Layer i Us aiiy magnesium oxide ortitaniurn dioxide i 25 rnicrorniiiirneters tnicilt i Reflects iignt toward him i Dyesii ithisiaye neipto ao so ion Waveiengtn iignt onotons wnicn reduces scattering oftne iig Slide 8 Components l Phosphor Layer 1 Active iayei ii i tne screen i Pnospnors aosoro ways and ernit iig hi I Varies from 150 to 300 micro millimeters thick Components I Protective Coat i la tic 25 micro millimeters thick i Protects pnospnoriayerfrom abrasions and stains i ifsci39e ens are scratched tne pnosonor crystals may be u ed cre exposed Wnite iine artiracts radiograp ating on tne nnisneo Slide 10 Slide ll Slide 12 Phosphors I Atomic Number i Hign atorn c n ton interactions l Conversion Ef cienc i Tne greater tne erricien produced I Spectral Emi 39 given rn on 4 Mus match the Sensitivity ofthe film urnper is required to produce pnotoeiectnc a d Corn cy tne rnore iigntis A5 Phosphors I Luminescence i Ablllly or a rnateriai to ernit iignt in response to excitation Lurninescent rnateriais ernit iigntWitn Wavelengths characteristic ortne rnateriai t Tnis resuits in iignt ernissions or a particuiar coior i Fiuore ence and pnospnorescence are two types oriurninescence Phosphors I Luminescence i Fiuorescence Occurs wnen iignt is emitted Witnin tne tirne ittakE and alert on to cornpiete one orbit oftne affected sneii eieetrons i instantaneous ernission Slide 13 Phosphors I Lumlne 1 Pnuspnurescen Occuvswnen ram ls emmed lungevlhan necessawluvune um uHhe mm m eleclmns Delaved Emlssl n en lay my anevgluw Occuvswnen n2 pnuspnuvcummueslu e moldemwav phumn enemv has ulsslpaled mm mm aner I Maxrnurnnuureseenee an pnu u rnrnrrnurn spnurescence ls desrrable Slide 14 Phosphors l Luminescence I As screens age pnospnors decrease ll l acllvlly 1 Normal llfe expectancy l5 5 e 7 years l All screens se ced by a srngle darkroom snould be replaced anne sarn Slide 15 Phosphor Types I Old l le lC Sul de l Barlum lead sulfate 1 Calciumtungs te r u 2 y Edlsun and wastne bes L untll late 197D l Rare E Gadullmum Lanthanum and Ynnurn Slide 16 Slide 17 Slide 18 Rare Earth Phosphors I Greater absorption intensi cation and f ciency I Use phosphors with atomic numbers of 5771 I 10 to 15 more ef cient than Calcium Tunstate I Offer increased speed while maintaining resolution Rare Earth Phosphors I Cost more tnan noncrare eartn screens I signiricantly reduce patientdose Pnospnortecnnology nas passed equipment tecnnology Some pnospnors are too fast I Tubes not fast enougn at producing exposure to ayoid quantum mottle aec reaction time lmum s erratic densities and grid line imaging Screen Characteristics I Resolution I ability to accurately image an ooiect l Controlled by tne size ortne pncispncir crystals i thlckness ortne crystal layer i concentration of crystals i Crystal siz layer tniclltness are both inyersely related to detail and directly related Slide 19 Slide 20 Slide 21 Screen Characteristics I Resolution Hign speed screens 7 iprnrn Resuiutiun FilmScreen Centaet F39uurfiimscreeri eentaet is cine eftne rneist eernrnein sereen reseiutiein prebiern S E age uensi Can be caused by fereign eibieets in tne cassette Warped screens damaged cassettes peer screen installatiun Screen Characteristics s r cuntaet between fiirn and screen I Quantum Mottle i Caused by insufficient pnospnor ernission frorn crystais i Resuits in insuffcient iigntpnotons striking tne tne screen 1 image appears grainy i Usuaiiy caused by insufficient rnAs cicirs Screen Characteristics l Speed 1 Screen Speed Ciassmcations i intensificatiuri femur measurement cittne arnpiiticaticin cittne image that ciccurs due tci cunversicin cit Xcrays tci iignt intensiticaticin tactcir DLDS Wnere DR EXpDSurE in rnR ncinscreen DL EXpDSurE in mR Witn screens Speed Screen Speed cia DESEHptW Screen Characteristics E Rain Hign speed ssificaticins i a P r d universal or medium Fine detaii nign resoluti n rnes vary according to manufacturer Slide 25 Slide 26 Slide 27 s ereeh Charadensncs Speed Sereeh Speed classr eaaehs Sp Reianye speedis based un par weed ahars arbraaniy assigned areiaaye speed RS number uf lEIEI as eehaei perm High speed sereehs areusuallyrated RS zuueizun ne detail sereehs areusuallyrated zuebu Screen Charadensncs Kshell Absorption Edge rlncideni photon matches or is slightly above or below the Keshell binding energy of the phosphor rResults rh signi cant increase or decrease rh lightproduced by seree 7 May significantly affect radiogaphic density s ereeh Charadensncs I The closerthe incident photon is to the K edge the more ef cient the screen I Rare Earth phosphors are much more ef cient than nonrare earth I K edge also affects speed Slide 28 Slide 29 Slide 30 lntenslrylng Screens Mzimznznce Handling Scmm mieilie luniileil caieiiillyin minimize the r39sk iii physical ii Awid iniiching the sum lntenslrylng Screens cleaning Screens should be cleaned at regular Intervals per manufacturer39s recommendations Potential contaminants that can cause artifacts include dust nger nail polish paper processing chemical s lashes soot cigarette ashes pen and pencil marks nasal spray delivered by sneezing a coughing coffee tea and sodas Use of incorrect cleaning solutions may cause a blotcliy appearance on the radiograph Label cassettes and screens so dlm screens can be easily identified Slide 31 Slide 32 Slide 33 Intensifying Screens Maintenance Testing Filmscreen comacnests using aWiremesh should be conducted periodically cassene and screen labeling is a valuable assa here as well Evaluation 5creens mustbe evaluated penodicallv for exposures must utlllzethe same exposurefactors FILM HOLDERS Cassellvs Purpose To provide a ponable lightproofcase To utilixe the intensifying screens to best a van age To anenuake the residual xray beam as much as possible FILM HOLDERS Cassellvs construction Must be rigid and lightweight Intensifying screens are attached to the inside of the from and back covers At least one onhese must be mounted on a foam pad to assure good lmscreen contact From Must be uniformly radiopaqueto prevent artifactformation plastic bakelite or carbon ber Back Must contain lead foil to minimize backscaner lesser am ounts for AEc cassettes Slide 34 Slide 35 Slide 36 FILM HOLDERS r m shapesliii all applicminns Lo dl Open cassette all the way Gently remove lm from lm bin or box while grasping it between thethuinb and index nger Do not usethree ngers which might cause kinks Using two hands lay lm in bottom orcassette Do not slide lm into cassette which might cause static buildup Close and latch cassette FILM HOLDERS Cassellvs unloading Unlatch and fully open cassette With the open cassette la ing on bench tilt cassette forward perinitting lm to fall from the well Pick the lm up using thethuin and index ngers of both hands Carry lm to processor and insert Reload cassette FILM HOLDERS Cassettes Maintenance clean exterior on a regular basis inspect and lubricate movlng parts hinge assembly latch assembly D door assembly should be stored on end like a book should be empty lueverhappensl Slide 37 FILM HOLDERS Dispnszhle PurposeThe lm comes prepackaged In adlsposable llgnt tlgnt envelope for dlrect exposure Appllcauon In the past these were used for extremmes because ortne excellent resoluuon out Is no longer used dueto Improvements In screen resolutlon and dose reducuon