Physics Ch 6 Fluoro

Question 1

max air kerma (exposure) rate?

Answer 1

87 mGy/min (10 R/min)

Question 2

pulse fluoro –> frame rate 30frame/sec –> dec to 15frame/sec –> dose reduce by what %?

Answer 2

50% dec pulse rate –> 30% dec dose

Question 3

pulse fluoro –> good for moving patients –> T/F? why?

Answer 3

T

sharper images w less motion blur

Question 4

image intensifier system (II) –> spatial resolution –> limited by what?

Answer 4

TV dispaly

Question 5

flat panel detector system (FPD) –> spatial resolution –> limited by what?

Answer 5

detector element size

Question 6

pixel binning –> how effect…

• pixel size
• spatial resolution
• mottle (noise)
• SNR

Answer 6

inc pixel size:

• spatial resolution dec
• mottle (noise) dec
• SNR inc

Question 7

fluoro –> QC test for spatial resolution?

Answer 7

lead bar pattern

Question 8

inc kVp –> dose dec/inc?

Answer 8

dec

Question 9

radiation injury of skin –> peak skin dose?

Answer 9

> 2Gy

Question 10

sentinel event –> how much cumulative dose?

Answer 10

> 15Gy (1500 rads)

Question 11

geometric magnification –> how effect…

• entrance skin kerma
• kerma area product

Answer 11

• air kerma –> inc

- KAP (DAP) –> no change

Question 12

KAP –> good indicator of deterministic risk (ie. skin burn) –> T/F?

Answer 12

F

Question 13

KAP –> good indicator of stochastic risk (ie. cancer) –> T/F?

Answer 13

T