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- RAD 150 Final Exams Practice 2025-
RAD 150 Final Exams Practice 2025-2026 ionizing radiation - CORR. ANSWER-x rays produce electrically charged particles along their path BERT method - CORRECT ANSWEF-background equivalent radiation time compares amount of radiation received from imaging procedure with natural background radiation received over a period of time thickness of lead apron - CORRECT ANSWER..25 inm Pb Primary barriers - CORR! 7 ft high 1/16" lead equiv ex: doors, walls Secondary barriers - CORRECT ANSWEF-absorb scatter radiation to the ceiling 1/32" lead equiv ex: wall of control booth RRE max leakage allowed by tube housing - C' ANSWER-100 mR/hr at lm away Fluoroscopic protection - CORRECT bucky slot cover exposure timer dead man switch rotating personnel lead apparel Where Lo stand during mobile radiography - ( 6 [Laway, 90 degrees from source Where to stand during C-arm procedures - CORRECT. ANSWER-behind physician factors that influence room design and barriers - CORRECT ANSWER-workload use occupancy workload - CORRECT ANSWER-avg radiation output x days per week room used use factor - C ANSWERdirection of beam for % of time occupancy factor occupancy of space behind barrier (controlled vs uncontrolled) Aperture diaphragm - CORRECT ANSWER-lead below housing with a hole which the beam allows slraighlosl radiation to le nue med 12% interventional 7% CT 24% consumer products 2% nuclear fallout 3% occupational .1% industrial .1% 1968 Radiation Control Act - CORR! exposures from consumer products RECT ANSWER set minimum education standards 2003 CARE bill- CORRECT ANSWER-required national licensure for technologists Dosimeter - CORRECT ANSWERdevice that measures individual occupational exposure Film badge - CORRECT ANS darker film = larger exposure aluminum filler measures shallow dose, coppor [iltor measures deep dase Control badge - CORRECT ANSWER kept in radiation free area records radiation during transport which is subtracted from personnel devices OSL dosimeter - CORR. ANSWEFP plastic holder, filters, aluminum oxide read with a laser light TLD dosimeter - CORRECT ANSWER-plastic haldor and lithium fhuoride er read by TLD analyzer exposure = intensity of hght Pocket Ionization Chamber - CORR. ER-most sensilive used by medical physicists gives immediate feedback Tonization chamber - CORR! gas filled ionization chamber that moasures x-ray, gamma, or bela radialion over a period of time Proportional counter - CORRECT ANSWER can detect low levels of radioactive contaminations used in a lab setting Geiger-Muller counter - CORRECT ANSWER-can detect lost sources of radiation has audible alarms that become louder as it gets closer to the source QF 20- CORRECT ANSWEF-alpha, fast neutrons, unknown energies American vs SI units- CORRECT ANSWEFR-RAD = Gray REM = Sievert Roentgen = C/Kg 100 RAD =- CORRECT ANSWER-1 Gy 100 Rem =- CORRECT ANSWER-1 Sv 1 Roentgen =- 08 x 104 C/ke or 3.88 x 10°3 R tissues ED=DxWRx WT WT .20- CORRECT ANSWER-gonads WT .01- CORRECT ANSWER-Skin, bone surface WT .05- CORRECT ANSWER Bladder, breast. liver, esophagus, thyroid, other Collective Effective Dose - CORRECT ANSWER internal and external measurements of groups of populations from low doses of ionizing radiation avg ED x # of persons exposed Total Effective Dose Equivalent (TEDE) - and control human exposure to ionizing radiation ANSWER-quantity to monitor .05 Sv oecupational .001 Sv general Coherent Scattering - CORRECT ANSWER-below 30 keV electron interacts with nucleus and is pushed out in different direction creates Bremstrahlung radiation, low energy primary beam/ small angle scatter Photoelectric interaction - { 30-150 KeV inner shell interaction energy totally absorbed, excess binding energy emitted as characteristic photon Compton scattering - CORRECT ANSWER-over 100 KeV outer shell interaction incident photon partially absorbed, elects compton scattered electron and compton photon Pair production - © NSWER-cnergics over 1.022 MoV photon interacts with nucleus and transformed into negatron and positron (511 MeV) non threshold mutational chances increase with increased exposure not dose dependent 1 Rom x age Annual occupational cffective dose limit - CORRECT ANSWER-30 mSv (5 Rom) Occupational lens of eye - CORRE SWER-15 rem Occupational skin, hands, feet and localized tissues - CORRECT ANSWER-30 Rem Non occupational annual effective dose limit - CORRECT ANSWERS mSv (.5 Rem) Non occupational lens of eye - COR. ANSWER-1.5 Rem Non occupational skin, hands, feet, and localized tissues - CORRECT ANSWER-5 Rem TAN: exposed dose limit - CORR. WER-..1 Rem embryo/fetus effective dose limit - Orem gestational period CORREC. Parts of a cassette film Film holders must be - CORRECT ANSWER-durable, light tight, easily accessible Layers of radiographic film - adhesive layer ctnulsion supercoating Film Base- CORRECT ANSWER-polyester flexible, durable, uniform lucency, dimmensional stability blue tint reduces glare Adhesive layer - CORRECT ANSWER-adheres cmulsion Lo base Emulsion - Ct ER-conlains active ingredients for image production (gelatin and silver halide crystals) gelatin - CORR! ANSWERtransparent easily penetrable maintains dimensional stability /SWER-undesirable fluctuations in densities due to large crystals and a thin emulsion Intensifying screens - C' EF-reduces patient dose by converting one invisible light photon to many visible light photons 33 % of photons - interact with intensifying screen first ANSWER-1,000-10,00 visible light Intensifying screen layers - CORRE‘ reflective layer phosphor layer protcclive coating IS Base - CORRECT ANSWEF-polyester reflective layer - CORRECT ANSWER-magnesium oxide or titanium dioxide reflects ight toward cmulsion dye often added to absorb longer wavelength scattered photons Phosphor layer - CORRECT ANSWEF-fluorescent crystals absorb energy and emit light photons types of phosphors - CORR. rare earths (gadolinium, lanthanum, yttrium) ‘E’-barium platinocyanide, calcium tungstate, @ coating - CORRECT ANSWER-plastic, protects phosphor layer from abrasions and stains Phosphor Characteristics - CORR! ANSWER-atomic # conversion efficiency spectral emission spectral matching luminescence cach x-ray photon spectral omission - cprecise wavclength of light emitted by phosphor spectral matching - CORRECT ANSWER-film used w a screen must be sensitive to the spectral emission of the screen R-glowing during cxposure ejection of electrons gives the sensitivity speck .....- CORRECT ANSWER-a negative charge What becomes attracted to the sensitivity speck - CORR! ANSWEF-tree silver ions Bromides and iodides migrate to - CORRECT ANSWER the gelatin silver migrates to- CORR: the process repeats until - CORRECT sensitivity speck 4 Steps of film processing - CORRE' Developing - -silver at latent image sites becomes visible developing reducing agents - CORRECT ANS phenidone - CORR: CTA. ER-warks quickly Lo produce shades of gray hydroquinone - CORRECT ANSWER-works slowly to produce black maintains alkaline pH and makes gelatin easier to penetrate developing restrainer - CORRECT. prevents developer from acting on unexposed silver halides developing hardener - CORRECT ANSWER-ghilaraldchy de controls swelling of gelatin, maintains uniform thickness and prevents abraisions Fixing - CORRECT ANSWER-removal of undeveloped silver halides bonds wilh unexposed silver halides 15-20 seconds Preservative - CORRECT ANSWER-sodium sulfite fixing hardener - potassium aluminum aluminum chloride, chromium aluminum, circulation system - CORRECT ANSWER stabilizes temp, agitates and mixes chemistry, filters solutions temp control system - C. temps Silver recovery methods - CORRE' chemical (slidging) (CT ANSWER-electrolysis of silver salt solution consisting of 2 electrodes metal exchange - CORRECT ANSWER-metal displacement from salt solutions by steel wool extraction AN, clectrolyle (Zine and Copper) Chemical sludging - efixer reacts wilh sodium dithionite or sodium sulphide to form a sludge containing silver Humidity - CORRECT ANSWER between 40-60% A0% creates static artifacts 60% film becomes wet and tacky, increases fog, reduces contrast darkroom light - CORRECT ANSWER indirect. wavelength matches film type inlensily no grcater than 23 walls convenuonal safolight - CORRECT ANSWER-amber orthochromatic safelight - CORRE: an expired film may have - CORRECT density, decreased contrast digital computer handle data in definite quantities ADC - CORRECT ANSWER-analog digital converter, converts analog photon stream to digital info Software - CORRECT ANSWER-instructions for calculations
