RT 244 / 328 REVIEW & REVISIONS

1. RT 244 / 328 REVIEW & REVISIONS 9.21.12 RHB SYLLABUS on Fluoroscopy & Radiation Protection

2. RHB NOTIFICATION (revised 2012) (RP Syllabus – pg68 Fluoro Syllabus pb 53) IMMEDIATE reporting – TOTAL DOSE OF 25 rems • Eye dose – 75 rem • Extremity – 250 RADS WITHIN 24 HOURS • TOTAL DOSE OF 5 rems • Eye dose – 15 rem • Extremity - 50 REMS ALL other OVEREXPOSURE – (received w/in 24 hrsMust be Reported WITHIN 30 DAYS

3. Report at least every quarterPreserved for indefinitely - individuala minimum of 3 years (employer)*(“all other records” pg 52)

4. Gonad shielding & dose • ♀ receive 3x more dose than • ♂ for pelvic x-rays • 1 mm lead will reduce exposure (primary) by about 50% ♀ • by about 90 – 95 % ♂(STAT) Pg 13 RHB –RP: 0.5 mm ↓ 92% (inc internal scatter) Pg 43 300 Rads ♀ 30 Rads ♂ -temp sterility

5. MONITORING PG 75 • CONTROLLED AREA – Used by occupationaly exposed personnel (monitored) • 100mrem / WEEK • UNCONTROLLED AREA – PUBLIC • 2 mrem per week*

6. HIGH RADIATION AREA – • 100 mRem ( 0.1 rem / (1 msV) • @ 30 cm from the source of radiaton • RADIATION AREA – • RHB: 5 mRem ( 0.005 rem / (.05 msV) • @ 30 cm from the source of radiation • PUBLIC 2 mrem per week* (STAT)

7. DOSE REGULATIONS • Fluoroscopic tubes operate at currents that range from0.5 to 5 mA with 3ma the most common • BEFORE 1974 - AT TABLETOP • 5R/MIN (WITHOUT AEC) Reg & Boost • After 1974 with AEC (1993 ) • 10 R/MIN 20R/MIN BOOST • Some books ave is 4 R/min if not given

8. Over vs under the table fluoro tubespg 116 dose to operator

9. DOSE • CINE - 2mR per frame (60f/sec) • 400 mr per “look”

10. SSD – TUBE TO SKIN DISTANCE • FIXED UNITS • 18” PREFERRED • 15 “ MINIMUM MOBILE UNITS ( C-ARMS) • 12’ MINIMUM • 5 min AUDIBLE ALARM

11. KEEP I.I. CLOSE TO PATIENT

12. Patient Protection • Tabletop exposure rate • Maximum 10 R/min • Typically 1 – 3 R/min

13. Patient Protection • Minimum source-to-skin distance • 12” for mobile equipment • 15” for stationary systems • Audible alarm at 5 mins. • Same rules for collimation

14. Shielding to Scatter Pg 70 Fluoro RHB: Scatter RT: 0.25 = ↓ 97% 0.5 = ↓ 99.9%

15. Lead curtain & dose reduction

16. Units of Dose – App #3 pg 79 100 R = 1 C/kg 1Rad = 1/100 Gray 1 Rem = .01 Sievert (Rad + QF = REM) 1 REM = 10 mSv 1 Rem = 1000mRem

17. Pregnancy & Embryo Mother – occupational worker (5 rem) • Baby – (500 mRem) • .5 rem/ year .05 rem/month • 5 mSv .5 mSv / month

18. 10 – 25 RAD Rule and Pregnancy Bush p 545 • Below 10 RAD (100mgy) ther ab NOT indicated • Above 25 RAD may justify TAB • FETAL doses RARELY reach 5 RAD

19. The NCRP states that: the risk (to the embryo/fetus) is considered to be negligible at 5 rads or less when compared to the other risks of pregnancy • and the risk of malformation is significantly increased above control levels only at doses above 15 rads

20. Kell Factor • The ability to resolve objects spaced apart in a vertical direction. • More dots = more scan lines = more/better resolution • Kell factor for 525 line system is 0.7 VERTICAL RESOLUTION = VER - TI- K- AL • RATIO OF VERTICAL RESOLUITON • # OF SCAN LINES more dots(globules) = more scan lines = more/better resolution

21. Bandpass/Horizantal Resolution • Horizontal resolution is determined by the bandpass. • Bandpass is expressed in frequency (Hz) and describes the number of times per second the electron beam can be modulated. • The higher the bandpass, the better the resolution