1. Area Problems You have 20” of string; figure the square area of: – A 5 X 5” square – A 4 X 6” rectangle – A 6.66 “ X 3.33” X 5.76” right triangle – A circle with a periphery of 20” (R= 3.183”)

2. Steps Draw the DAMN picture! Write the equation Fill in the knowns and unknowns on the picture Work the problem Re-read the question to see if you did what it asked Do a “quick mental check”

3. Problems If you had collimator settings of 8 X 10” at 40” SID, what would the resultant field size be at 50” SID if NO changes in collimator settings were done (direct proportion)? If you were in fluoro and standing 24” away from the fluoro tube and received a dose of 20mR, what dose would you receive at 48” (inverse square law)?

4. More problems If you were doing a PCXR and used 10 mAs and 80 kVp at an SID of 40”, what distance would receive only 2.5 mAs (inv. sq. law)? If you had a great technique for a CXR of 115 kVp and 10 mAs at 40: SID, what mAs would you need to use at 80” SID to get the SAME radiographic density (Old mAs/New mAs)?

5. No more clues! You did a PCSR yesterday using 10 mAs, 70 kVp @ 40” SID. Today, you can only get a 50” SID. What technique would give you the same radiographic density as yesterday’s? You received a dose of 10mR/min @ 2Ft. From the fluoro table in 5 minutes. How far away would you need to stand to only receive 2.5 mR in 5 minutes?

6. Con’t A man was stabbed with a 4” blade. The blade shows up as 6” long on the image made @40” SID. How far away from the film/receptor is the blade? You totaled 182 pts. Of 200 possible in this class, what is your percentage of the total pts?

7. More You used 100 mA @ 1 sec with 70 kVp, but got motion on the image. What new time can you use to lesson motion if you now use 500 mA? If you had a great technique @40” SID with 6 mAs/70kVp, but could only get a 50”SID on a follow up, what new mAs would you use?

8. Ditto If you were receiving 4 R/min. during fluoro @ 20” from the fluoro table, how far away would you need to stand to only receive 2 R/min? An x-ray unit puts out 80 mR@ 40” SID. How far away from the same unit with the same factors would receive only 20mR?

9. Double ditto A portable machine exposure is 20 mR @ 40” SID. What is the new exposure at 80 SID (w/o technique changes)? You are using a technique of 20 mAs and 70 kVp. You must double your exposure density, but you have exceeded tube limits. What should you do to be able to make a more dense OD, but NOT exceed tube limits?