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Fluoro & Rad Protection. Review Questions For WEB RT 255 wk 7/8. __________ – Input Phosphor _______________ – Output phosphor ELECTRON FOCUSING LENS + CURRENT ATTRACTS e TO ANODE _________ KVP POTIENTIAL ACROSS TUBE. IMAGE INTENSIFIER. MEASURED IN ???? IP VS OP. FUNCTION:
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Fluoro & Rad Protection Review Questions For WEB RT 255 wk 7/8
__________ – Input Phosphor _______________ – Output phosphor ELECTRON FOCUSING LENS + CURRENT ATTRACTS e TO ANODE _________ KVP POTIENTIAL ACROSS TUBE IMAGE INTENSIFIER MEASURED IN ???? IP VS OP
FUNCTION: CHANGE XRAY PHOTONS TO __________ PHOTONS (INPUT PHOSPHOR) TO __________(PHOTOCATHODE) IMAGE INTENSIFIER
The ratio of the number of light photons striking the output screen to the ratio of the number of x-ray photons striking the input screen is called _____________ Defines?
MAG MODE VS PT DOSE • MAG USED TO ENLARGE SMALL STRUCTURE OR TO PENETRATE THROUGH LARGER PARTS • FORMULA:???? • PATIENT DOSE IS INCREASED IN THE MAG MODE – • DEPENDANT ON SIZE OF INPUT PHOSPHOR
MAG MODE VS PT DOSE • MAG USED TO ENLARGE SMALL STRUCTURE OR TO PENETRATE THROUGH LARGER PARTS • PATIENT DOSE IS INCREASED IN THE MAG MODE – • DEPENDANT ON SIZE OF INPUT PHOSPHOR • FORMULA:????
Name of Pattern of electon beam? # of lines for Conventional vs Digital monitors Horizontal Resolution? Vertical Resolution? TV Monitor
VERTICAL RESOLUTION ABILITY TO RESOLVE OBJECTS SPACED APART IN A VERTICAL DIRECTION MORE DOTS(GLOBULES) = MORE SCAN LINES = MORE/BETTER RESOLUTION RATIO OF VERTICAL RESOLUITON # OF SCAN LINES KELL FACTOR FOR 525 LINE SYSTEM IS ____________________ KELL FACTOR
PLUMICON, VIDICON, ORTHOCON, CCD’s • Function? • CONNECTED BY • MOST COMMOM • BETTER RESOLUTION & Lower pt dose? • – VERY $$$$ • Type used in Digital Units? VIDEO/CAMERA TUBE
Terms that are necessary to know: • Vignetting is • Pincushion effect • Quantum mottle is • The _____of the II will always have the best resolution. • Lag is Image Quality
Terms that are necessary to know: • Vignetting is the loss of brightness at the periphery of the II due to the concave surface • Pincushion effect is the drop off at the edges of the II due to the curved surface • Quantum mottle is the grainy appearance on the image due to statistical fluctuations • The center of the II will always have the best resolution. • Lag is the blurry image from moving the II too fast Image Quality
Image Quality - Define • Contrast is controlled by? • Resolution • Size Distortion is affected by • Quantum mottle • What is it and what causes it?
Fluoroscopic tubes operate at currents that range from With ___________the most common AEC rate controls: equipment built after 1974 with AEC shall not expose in excess of __R/min; equipment after 1974 without AEC shall not expose in excess of ____ R/min Regulations about the operation
Must have a ____________ switch Must have __________ exposure timer Must have an ______to prevent exposure without II in place Tube potential must be tested ________ Brightness/contrast must be tested _______ Beam alignment and resolution must be tested _____ Leakage cannot exceed __________ Other regulations
FIXED UNITS • ____PREFERRED • _____MINIMUM MOBILE UNITS ( C-ARMS) _____ MINIMUM SSD – TUBE TO SKIN DISTANCE
Must have a device to prevent operation at a SOD of less than ___________ A bucky slot cover must be provided Aprons must be at least _______Pb equivalent ________Al equivalent filtration is required Must provide at least _____ and preferably ______ between source and table top more regulations
For radiation protection purposes the fluroscopic table top exposure rate must not exceed __________/min. The table top intensity should not exceed ____ R/min for each mA of current at____ kVp Fluoroscopy exposure rate
1 Rem = .01 Sievert 1 REM = _____mSv 1 Rem = _____mRem ? measurement
100 R = 1 C/kg 1Rad = 1/100 Gray 1 Rem = .01 Sievert (Rad + QF = REM) 1 REM = 10 mSv 1 Rem = 1000mRem measurement
______ OF OCCUPATIONAL NON MEDICAL EXPOSURE _____ RAD OR _____MRAD UNDER AGE 18 AND STUDENT .1 rem 1 mSv Pg 98 RTA BOOK PUBLIC EXPOSURE ?
INTERGRAL DOSE – 100 ERGS OF TISSUE = 1 RAD EXPOSURE OR ___ RAD =___ERGS
NAME 4 WAYS TO LIMIT DOSE TO THE PATIENT DURING FLUORO EXAM PATIENT PROTECTION
According to your California syllabus, list more 6 things that will reduce patient exposure:
MUST BE . ______ OF LEAD MUST BE USED WHEN GONADS WILL LIE WITHING _____ OF THE COLLIMATED AREA (RHB) KUB. Lumbar Spine Pelvis male vs female shielding GONAD SHIELDING
♀ receive _____ more dose than ♂ for pelvic x-rays 1 mm lead will reduce exposure (primary) by about ______♀ by about ________♂ Gonad shielding & dose
135 under 45 over Degree of scatter??
The use of the available film area to control the image as seen from the output phosphor. • Underframing • _______ is best, (58 % lost film surface) • Overframing,(part of image is lost) • Total overframing Framing and patient dosesyll = Pg 31 which is BEST
IF MACHINE OUTPUT IS 2 R/MA/MIN = WHAT IS PT DOSE AT 1.5 MA FOR 5 MIN STUDY? EXPOSURE RATES FLUORO
CURRENT STANDARD _______ R/MIN (INTENSIFIED UNITS) HLC: BOOST MODE _______ R/MIN EXPOSURE RATES FOR FLUORO
Lower at a _____ DEGREE ANGLE from the patient + PRIMARY BEAM AT 1 METER DISTANCE - • _______ OF INTENSITY PRIMARY XRAY or 0.1% RADIATION PROTECTIONThe Patient is the largest scattering object
The law requires that total filtration during fluoroscopy should be __________________
Between spot film cassettes and photospot films,the_____will increase patient dose. However, between the two the ______will produce better image quality.
The x-ray tube current automatically increases to ________level of mA when a spot film is taken.
List one RECORDING method that HAS LOWERPATIENT DOSE: ______________________
When recording dynamic images using cine, the higher the frames per second, the ___________ the patient dose
STANDING BEHIND A PROTECTIVE PRIMARY (-of ____ pb) BARRIER: PRIMARY RADIATION EXPOSURE _____REDUCED PORTABLE BARRIER = _____REDUCTION PERSONNEL PROTECTION
PROTECTIVE APRONS – 0.25 PB = ____ ↓ TO SCATTER 0.5 PB = _____ ↓ TO SCATTER THYROID SHEILDS (____________ mm pb) GLOVES (____________ mm pb) PERSONNEL PROTECTION
PERSONNEL PROTECTIONMONITORING • FILM BADGE • TLD • POSL • POCKET DOSIMETER • RING BADGE • Which is most sensitive to radiation? • Which one has a permanent record?
DOSE LIMITS WHOLE BODY __________ EYES _________________ EXTREMITIES (BELOW ELBOW/KNEES) PERSONNEL PROTECTIONMONITORING
Report available at least _________Preserved for a minimum of _____years
IMMEDIATE – REPORT WITHIN _________________________ TOTAL DOSE OF 25 rems Eye dose – 75 rem Extremity – 250 RADS RHB NOTIFICATION (
OVEREXPOSURE – Report within ________________ TOTAL DOSE OF 5 rems Eye dose – 15 rem Extremity - 50 REMS RHB NOTIFICATION (EXP IN 24 HOURS)
WITHIN ________OF EXPRIATION NOTIFICATION OF CHANGE OF ADDRESS LICENSE RENEWAL
HIGH RADIAITON AREA – • ___________mRem ( 0.1 rem / (1 msV) • @ 30 cm from the source of radiation