Standard fluoro dose rate is 1 rad/min 1-5 rad/min The table top exposure rate for routine fluroscopy shall not exceed 5 roentegens/in Tube current and potential must be monitored and recorded Weekly Beam alignment and image intensifier resolution monitored Monthly At 80 kVp, intensity at bedside should not exceed for each milliampere of current 2.2 roentgens/min MaxExposure Rate of Fluorscopic Beam on typical patient 5R/min Max allowable exposure to person in controlled area 100mR/week Maximum permissable dose to person in uncontrolled area 10mR/week Maximum permissable leakage radiation from diagnostic-type-xray tube housing at 1 meter 100mR/hour Immediate notification exposure total 25 rem Immediate notification eye 75 rem Immediate notifation skin 250 rem Does to be report in 24 hours. 5 rems Dose must be reported to regulatory agency in 30 days 2 rem Dose must be reported to regulatory agency in 30 days 1.3rem/quarter Maximum allowable whole body occupational dose 1250 mrem/quarter Magnitude of scatter at 1-3 feet from bedside during fluroscopy 50-500mR/hr Minimum Filtration Requirement for Fluroscopic Equipment 2.5mm alumn Recomended Dose to Fetus during pregnancy .5rem/8mos Maximum Recommended Exposure for Xray to be Stored for 1 month 02 mR/week Max intensity of xray beam where it enters patient for each milliampere of current 2.2 R/min Maximum tabletop dose rate when aquiring images without recoding devices 20 rads/min Maximum whole body dose in one hour in high radiation area 100mRems/hour Maximum whole body dose in one hour in radiation area 5mRems/hour Amount of rads to abdoment to cause miscarriage, stillbirth, 25 rads Accepted integration time of the eye. .2 sec Measurements of exposure rates using AEC should be made at least Yearly In upper GI in pregnant womne, total skin is 5, what is fetus exposrure 100 millirad Cardiac catherization results in bone marrow dose of approx 190 millrads Dose to goands resulting from barium enema exam 500 millirads Approximate exposure a pateint would receive during 5 minute fluoroscopy 10-30 roentgens CINE in which 35 mm film, frame rate 30/sec, approx skin exposure 2-5 roentgens/min Units Erg unit of energy Roentgens unit of exposure the measure of output radiation intesnity of a fluoro tube Rad unit of dose one Rem of xray = 1 rad SI = gray 1 Gray = 100 rads Rem unit of dose equivalent SI = Sievert 1 Sv = 100 rems calculation Rem = Rad x QF In Xray QF = 1, therefore exposure = does = dose equivalent1 roentgens = 1 Rad = 1 Rem Exposure Background radiation 100 milliroentgens CXR 20 mR Abdominal Xray 200 mR CT scan 2,000 mR (2 roentgens) Fluoro Exam 2,000 - 6,000 mR/min (2-6 roentgen/min) upper GI exam (3 roentgnes/min) (6 R for 2 minute exam) than exposue to fetus is 100 millirads (2%) CineRad 20,000 - 100,000 mR/sec (20-100 roentgens/min) Dose Cardia catheterization 190 millirads Barium Enema exam 1000 millirads is exposure to gonads Patient Care 9 Questions 1. Patient Interactions & Management 9 Questions Patient Identifications and Procedure Verification Task 1: Confirm patient identity Task 9: Examine imaging examination requisition to verify accuracy, completeness of information, and exam appropriateness) Components of Informed Consent Task 10: Verify or obtain patient consent as necessary (e.g,. contrast studies) Risk versus Benefit Patient Educations explanation Task 2: Advocate radiation safety and protection Task 6: Evaluate patients ability to understand and comply with the requirements for the requested examination response to inquiries (radiation dose, types of radiation) Procedural Understanding to Reduce Exposure Cumulative Dose Education Pregnancy Status Task 5: Assess risk factors that may contraindicate the procedure (health history, medications, pregnancy, psychological indicators, alternative medicines) Task 8: Question female patient of child-bearing age about the date of last menstrual period or possible pregnancy and take appropriate action (contact physician, document response) Contrast Reaction allergy history (appropriate pre-medication) types of reactions (mild to severe) Patient Record Information patient dose / technical factors Task 3: Assess the patient's radiation dose and history Task 4: Assess alternative procedures based on patient dose adverse reactions picture archiving and communication system (PACS) hospital information systems (HIS) radiology information systems (EMR) Standard of Care using fluoro to position patient prior to a normal radiograph is prohibited. HIPPA Task 2: Obtain pertinent medical history Safety 46 Questions 1. Radiation Physics and Radiobiology 22 Questions A. Radiation Physics Photon interactions with matter (5.5 questions) Compton effect (1.3 questions) photoelectric absorption (1.3 questions) coherent (classical) scatter (1.3 questions) attenuation of various tissues (1.3 questions) thickness of body part type of tissue (anatomic number, density) higher atomic number (bone) will absorb more xray X-ray production (5.5 questions) source of free electrons (e.g., thermionic emission) acceleration of electrons focusing of electrons deceleration of electrons target interaction (x-ray spectrum) bremsstrahlung characteristic X-ray Bean (5.5 questions) frequency of wavelength beam characteristics quality quantity primary verses remnant scatter inverse square law fundamental properties (e.g., travel in straight line, ionize matter) Radiation Biology (5.5 questions) radiosensitivity dose-response relationships relative tissue radiosensitivity appear to follow linear - nonthreshold dose pattern influenced by dose rate of radiation type of radiation total dose received by tissue type of tissue size of cell is NOT a factor. cell survical and recovery oxygen effect somatic effects short term verse long-term effects acute verses chronic effects carcinogenesis organ and tissue response eye thyroid breast bone marrow skin gonadal embryonic and fetal risks genetic effects 2. Radiation Protection 24 Questions Minimizing Patient Exposure (12 questions) exposure factors kVp * want this to be high determines max photon energy optimizing this largery determines quality of image based on maximal differential absorption the the tissue tube used in fluoro are capable of operating at 125-150 kVP (thus need filtration) mA * want this to be low tube currents of 0.5 to 5 mA (1-3mA) a spot film mA is > 100 (but used with very short exposure time 100 msecs) fluoroscopy time (exposure time) reduced by dead-man swith or pedal, only on when pushed exposure time is directly related to radiation exposure automatic brightness control (ABC) automatic exposure rate control (AERC) allowable exposure rates (x-ray intensity) may ot exceed five rads per minute (does not apply when using automatic brightness control on fat patients) shielding rationale for use types placement beam restriction purpose of primary beam restrictions collimators* restriction or area of the exposed field is required by law one of most important ways a fluroscopic can avoid unecessary radiation the greatest contribution of unnecessary radiation exposure to patient comes from xray operators failure to collimate the x-ray beam in the area of clinical interest. a well collimated image is better in quality usually located in useful (primary) xray beam path filtration * effect on skin and organ exposure effect on average beam energy NCRP recommendations (NCRP #102, minimum filtration in the useful beam) overview tube used in fluoro are capable of operating at 125-150 kVP and filtration of 3mm aluminum equivalent mused be used is necssary to protect patient's skin from receiving the unnecessary radiation dose equipment features last image hold cumulative manual-reset timer records the amount of xray on time predetermined time limit may not exceed 5 minutes magnification mode 9 inch input phospur 6 inch input phosphor when need vto view small area minification gain decreaseds thus need to increas mS thus patient radiation increaseds going from normal (9inch) to mage(6inch) dose mode low dose cine high-level control pulsed pediatric dose reduction grids receptor positioning patient positioning impact on dose patient immobilization devices dose or time documentation exposure switch dose area product (DAP) meter air kerma display minimum source to skin distance (21 CFR) source to tabletop distance (STD) important for under-the-table and over-the-table or c-arm target to panel distance optimal is 18 inch minimum is 12 inches. patient to image intensifier distance* Personnel Protection (12 questions) sources of radiation exposure primary xray beam secondary radiation scatter factors affecting an increase in radiation include High kilovoltage large field size thick body part (fat people) leakage patient as source basic methods of protection time allowable exposure time exposure time distance shielding protective devices protective drapes* must be .25 mm lead equivalent positioned between patient and fluoroscopist to intercept scatter radiation coming from the patient primary function is to reduce scatter coming from the patient scatter from patient can be as high as 500millrads per hour Bucky slot cover* Bucky tray is moved to end of table which leaves an opening two inches wide. opening must automatically covered with at least 0.25 millimeters lead equivalent material shields* apron gloves eye face floating thyroid attenuation properties cumulative timer remote-controlled fluoroscopy minimum lead equivalent (NCRP #102) guidelines for fluoroscopy and mobile units fluoroscopy exposure rates (e.g., normal high-level control) exposure switch guidelines recommendations for personnel monitoring (NCRP#116) occupational exposure' public exposure embryo/fetus exposure ALARA and dose equivalent limits evaluation and maintenance of personnel dosimetry records units of measurement absorbed dose dose equivalent exposure effective dose air kerma dosimeters types acceptable personnel montiroing devices are film badge measured in rems thermoluminescent dosimeter proper use Limits Society no members of publick in unrestricted area (waiting room) will receive .1 rems / year (100 millirems/year) .002 in any hour (2 millirems/hour) Patients Occupational yearly no one patient occupational exposure more than 5 rems in one calendar year pregnant work .5 rems during the entire pregnancy. (500 millirems) .05 rems in any month (50 millirems) Want KvP to increase (quality) so mA (quantity) so decrease patient skin exposure decrease scatter decrease operator exposure decrease contrast decrease image distortion Factor that directly affects milliamperage (mA) Kilovoltage (KvP) Collimation Filtration Exposure time Target to panel distance (TPD) Patient to image intensifier distance (for over-the-table and under-the-table systems) sensitivity of the image receptor Factors that directly reduce patient exposure collimating in area of interest only using last-fram-hold keep patient-to-image intensifier distance short use highest kVp use lowest milliamperage (mA) used pulsed fluoro woth lower frame rates use largest image intensifier mode (avoid mag mode) with strict collimation Image Production 35 Questions Equipment Operations 22 Questions Technical Factors (4.4 questions) kVP mA object-to-distance (OID) source-to-distance (SID) focal spot image grids filtration beam restriction automatic brightness control automatic exposure rate control (AERC) anatomic alignment exposure compensation magnification mode spot imaging (digital spot) high-level control boost high dose rate pulse rate Source (xray tube) cathode serves as source of electrons rotating anode produces the xrays made of Tungsten Image Receptors (4.4 questions) image intensifier functions to amplify the brightness of the image amplification measured in brightness gain. minification gain (same # electrons on 1 inch screen instead of 12 inch) flux gain is at output total brightness gain = minification gain x flux gain xray images input phosphor layer of fluorescent material that converts xray energy into light photons when amount of absorbed photons is low then get quantum mottle or grainly images photocathode converts light photons into electrons accelerating anode (electronic lenses) accelerates electrons brightness gain achieved by accelerating electons output phosphor converts electrons to photons flat panel detector Image Display (4.4 questions) viewing conditions luminance the brightness and contrast on the tv screen can be changed to help see the image ambient room lighting should be dim to enhance visualization of the black and white image eye physiology ergonomics spatial resolution pixel size pixel pitch contrast resolution/dynamic range DICOM gray scale function brightness and contrast Recording Systems (4.4 questions) digital subtraction angiography (DSA) image capture spot imaging (digital spot) Imaging Information (4.4 questions) digital imaging and communications in medicine (DICOM) picture archiving and commuications systems (PACS) radiology information system (RIS) modality workist hospital information system (HIS) electronic medical record (EMR) or electronic health records (EHR) Display of documents in area where xrays produced Certification documents each xray supervisor and operator permit each technologist certificate each technologist fluoroscopy permit "Notice of Employees" by Radiographic Health Department Laws and Regulations copy of the California Radiation Control Regulations operating procedures applicable to working with fluoroscopy Image Evaluation and Quality Control 12 Questions Digital Image Characteristics (4 questions) spatial resolution (equipment related) sampling frequency (framing frequency) patient radiation increases as the framing frequency (frame rate) increases detector element size (DEL) size pitch fill factor image signal (exposure related) quantum mottle (quantum noise) dynamic range signal to noise ratio (SNR) contrast to noise ratio (CNR) contrast resolution (equipment related) bit depth modulation transfer function (MTF) detectice quantum efficiency (DQE) Criteria for Image Evaluation (4 questions) demonstration of anatomical structures positioning motion identification markers (radiographic or electronic) anatomical patient date patient considerations (e.g. pathological conditions) quantum mottle (quantum noise) grainy appearance when not enough photons absorbed by image intensifier mottle can be improved by gross exposure error loss of contrast saturation contrast spatial resolution distortion size shape image artifacts grid lines dead pixels distortion pincushion distortion is artifact at the edges lag - motion artifact vignetting - when center is brighter than the edges Recognition and Reporting of Malfunctions (4 questions) quality control (2 questions) display monitor (1 questions) grayscale standard display function luminance shielding accessory testing (1 questions) lead apron testing glove testing exposure rate control (1 questions) spot imager (1 questions) image quality (1 questions) resolution recording and reporting of overexposure (2 questions) Equipement States Limits Tube Leakage .1 roentgens (100 milliroentgens) cannot exceed distance of 1 metter from target State Exam Limits 12 inch (30 cm) system must block from source to skin distance being less than this Annual Occupation Dose Equivalent Limits (adults over 18) adults .5 rem whole body during gestational period (9months) 5 rem whole body (total effective dose equivalent) 15 rem lens or eye (eye dose equivalent) 50 rem skin and extremity under 18 10% of limits above individual members of public in unrestricted area .1 rem (100 mrem) .002 rem in any one hour (2 mrem in any hour) prenatal dose to embryo/fetus .5 rem during gestational period (9 months) State notification immediate (5x above) 25 rem or more of total effective dose 75 rem or more eye dose 250 rem 24 hours notification if worker receives in 24 hours (same as annual but in 24 hours) 5 rems total 15 rems eye 50 skin Radiation Area high radiation area .1 rem / hour at 30 cm from source radiation area .005 rem / hour at 30 cm State Notification immediate 25 rem or more of total effective dose 75 rem or more eye dose 250 rem skin does within 24 hours if exposed within 24 hours (1/5 of above) 5 rem total 15 rem eye 50 rem skin report to state within 30 days in 2 rem in a calendar quarter Scattered radiation at 12 inches fromu patient at hight as 500 milliroentgens/hour (mR) or .5 roentgens/hour. Boost in IR max dose rate of 20 rads per minute when aquiring without video Typical for spot filming 100 mA Exposure #s Scatted radiation 500mR/hr at 1 foot Max at table for each mA of current 2.2 R/min Area #s Radiation Area high radiation area .1 rem (100 milirems) / hour at 30 cm from source radiation area .005 rem (5 milirems) / hour at 30 cm Equipment # .25 lead equivalent automatic coverage of bucky tray .25 lead equivalent min apron Biologic Damage #s Embryo Deleterious Effects 10 rads Risk of embryo malformation 15 rads Spontanoeus abortion 50 rads Cataracts several hundred rads Calculations During a 2-minute fluor for upper GI series, a typical xray exposure to patient is 6.0 roentgens If given kVP, delivers 4 mR at 40 inches then at 80 inches radiation output from tube (in mR/mAs) will be 1 If 3 grams of tisse absord 300 ergs of xray, what is the dose 300/3 = 100 ergs/gram = 1 rad Definitions Dose (Rad = Radiation absorbed dose) radiation absorbed per unit mass 1 rad = 100 ergs/gram rad - gray (Si units) 1 gray = 100 rads Dose Equivalent = Rem (sievery in SI) Whole body dose head eyes and brain trunk all organs arms above elbow legs above knee Occupational dose dose received by any individual during course of employment erg unit of energy milliroentgens the measure of output radiation intesnity of a fluoro tube Rem one Rem of xray = 1 rad Rad