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FLUOROSCOPYIMAGES
IN
MOTION
FLUOROSCOPYEQUIPMENT
PATIENT EXPOSURE
• REDUCE DISTANCE OF IMAGE INTESIFIER
• INCREASE DISTANCE FROM THE TUBE
SIE of 100 R-cm2 compared to only 10 R-cm2 for the lady on the left.
Here is a good example of where just knowing the exposure (100 mR), dose not tell the full story.
Radiation protection was primarily a non-governmental function until the late 1940s. After World War II, the development of the atomic bomb and nuclear reactors caused the Federal government to establish policies dealing with human exposure to radiation. In 1959, the Federal Radiation Council was established
GSD p185
• GENETICALY SIGNIFICANT DOSE• Takes all of the population into account• Annual AVERAGE gonadal dose to
population of childbearing age
• 0. 20 mSv or 20 millirem • rem or rad???
RADIATION DOSE TO PATIENTS
• ESE - ENTRACE SKIN EXPOSURE (MEASURED BY A TLD)
• SKIN DOSE• GONADAL DOSE• BONE MARROW DOSE• (MEAN GLADULAR DOSE- MAMMO)
• ** SEE TABLE 1-5 PG 17 &• 1-8 PG 18 (carltons)
PEDIATRIC EXPOSURE
• MORE SENSITIVE TO RADIATION THAN ADULTS
• LIMIT BEAM TIME • MAY REMOVE GRID (REDUCE
EXPOSURE)• AP VS PA• COLLIMATION & SHIELDING !!!!!!!!!!!!!!!• GENDER DIFFERENCES• IMMOBILATION
RADIATION PROTECTION
• PG 204 CARLTONS
• AT 90 DEGREE ANGLE
• TO PRIMARY BEAM
• AT 1 METER DISTANCE
• 1/1000 OF INTENSITY PRIMARY XRAY
ROOM SHIELDING
• PRIMARY SHIELD – PRIMARY BEAM DIRECTED AT WALL
• 1/16 LEAD 7 FEET HIGH• SECONDARY – NO PRIMARY BEAM• 1/32 LEAD• CONTROL BOOTH (SECONDARY)• BEAM SCATTERS 2X BEFORE HITTING• LEAD WINDOW – 1.5MM LEAD EQ
LEAKAGE RADIATION
•TUBE HOUSING 100MR / HR @ 1 METER
ROOM USAGE
• WORKLOAD FACTOR (W) =radiation output x usage mas/week or ma-min/week
• USE FACTOR (U) BEAM ON TIME
• OCCUPANCY FACTOR (T) – used for shielding requirements for a particular barrier
MONITORING
• CONTROLLED AREA – USED BY OCCUPATIONALY EXPOSED PERSONNELL (MONITORED)
• 100mrem / WEEK
• UNCONTROLLED AREA – PUBLIC
• 2 mrem per week*
PREGNANT PATIENTS
• ASCERTAIN LMP - IF FETUS IS EXPOSED• PHYSICSTS WILL NEED INFORMATION:• WHICH XRAY MACHINE USED (MR/MAS)• # OF PROJECTIONS (INC REPEATS)• TECHNIQUE FOR EACH EXPOSURE• SID • PATIENT MEASUREMENT AT C/R• FLUORO TIME & TECHNIQUE USED• PHYSICIST WILL CALCULATE FETAL DOSE
